media.xml

<?xml version="1.0" standalone="no"?>
<!--

    Copyright (c) 2012, 2023 Oracle and/or its affiliates. All rights reserved.

    This program and the accompanying materials are made available under the
    terms of the Eclipse Public License v. 2.0, which is available at
    http://www.eclipse.org/legal/epl-2.0.

    This Source Code may also be made available under the following Secondary
    Licenses when the conditions for such availability set forth in the
    Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
    version 2 with the GNU Classpath Exception, which is available at
    https://www.gnu.org/software/classpath/license.html.

    SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0

-->

<!DOCTYPE chapter [
        <!ENTITY link.moxy "<link linkend='json.moxy'>MOXy</link>" >
        <!ENTITY link.json-p "<link linkend='json.json-p'>Java API for JSON Processing (JSON-P)</link>" >
        <!ENTITY link.jackson "<link linkend='json.jackson'>Jackson</link>" >
        <!ENTITY link.jettison "<link linkend='json.jettison'>Jettison</link>" >
        <!ENTITY link.json-b "<link linkend='json.json-b'>Java API for JSON Binding (JSON-B)</link>" >

        <!ENTITY % ents SYSTEM "jersey.ent" > %ents;
]>
<chapter xmlns="http://docbook.org/ns/docbook"
         version="5.0"
         xml:lang="en"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xmlns:xlink="http://www.w3.org/1999/xlink"
         xsi:schemaLocation="http://docbook.org/ns/docbook http://docbook.org/xml/5.0/xsd/docbook.xsd
                             http://www.w3.org/1999/xlink http://www.w3.org/1999/xlink.xsd"
         xml:id="media">

    <title>Support for Common Media Type Representations</title>

    <section xml:id="json">
        <title>JSON</title>

        <para>
            Jersey JSON support comes as a set of extension modules where each of these modules contains an implementation of
            a &jaxrs.core.Feature; that needs to be registered into your &jaxrs.core.Configurable; instance (client/server).
            There are multiple frameworks that provide support for JSON processing and/or JSON-to-Java binding.
            The modules listed below provide support for JSON representations by integrating the individual JSON frameworks into
            Jersey. At present, Jersey integrates with the following modules to provide JSON support:

            <itemizedlist>
                <listitem>
                    <para>
                        &link.moxy; - JSON binding support via MOXy is a default and preferred way of supporting JSON binding
                        in your Jersey applications since Jersey 2.0. When JSON MOXy module is on the class-path, Jersey will
                        automatically discover the module and seamlessly enable JSON binding support via MOXy in your
                        applications. (See <xref linkend="deployment.autodiscoverable" />.)
                    </para>
                </listitem>
                <listitem>
                    <para>&link.json-p;</para>
                </listitem>
                <listitem>
                    <para>&link.jackson;</para>
                </listitem>
                <listitem>
                    <para>&link.jettison;</para>
                </listitem>
                <listitem>
                    <para>&link.json-b;</para>
                </listitem>
            </itemizedlist>
        </para>

        <section>
            <title>Approaches to JSON Support</title>

            <para>
                Each of the aforementioned extension modules uses one or more of the three basic approaches available when
                working with JSON representations:

                <itemizedlist>
                    <listitem>
                        <para>POJO based JSON binding support</para>
                    </listitem>
                    <listitem>
                        <para>JAXB based JSON binding support</para>
                    </listitem>
                    <listitem>
                        <para>Low-level JSON parsing &amp; processing support</para>
                    </listitem>
                </itemizedlist>

                The first method is pretty generic and allows you to map any Java Object to JSON and vice versa.
                The other two approaches limit you in Java types your resource methods could produce and/or consume.
                JAXB based approach is useful if you plan to utilize certain JAXB features and support both XML and JSON
                representations. The last, low-level, approach gives you the best fine-grained control over the out-coming
                JSON data format.
            </para>

            <section xml:id="json-pojo">
                <title>POJO support</title>

                <para>POJO support represents the easiest way to convert your Java Objects to JSON and back.</para>
                <para>Media modules that support this approach are &link.moxy;, &link.jackson;, and &link.json-b;</para>
            </section>

            <section xml:id="json-jaxb">
                <title>JAXB based JSON support</title>

                <para>
                    Taking this approach will save you a lot of time, if you want to easily produce/consume both JSON and XML
                    data format. With JAXB beans you will be able to use the same Java model to generate JSON as well as XML
                    representations.
                    Another advantage is simplicity of working with such a model and availability of the API in Java SE Platform.
                    JAXB leverages annotated POJOs and these could be handled as simple Java beans.
                </para>
                <para>
                    A disadvantage of JAXB based approach could be if you need to work with a very specific JSON format. Then it
                    might be difficult to find a proper way to get such a format produced and consumed. This is a reason why a
                    lot of configuration options are provided, so that you can control how JAXB beans get serialized and
                    de-serialized. The extra configuration options however requires you to learn more details about the framework
                    you are using.
                </para>

                <para>
                    Following is a very simple example of how a JAXB bean could look like.

                    <example>
                        <title>Simple JAXB bean implementation</title>
                        <programlisting language="java" linenumbering="numbered">@XmlRootElement
public class MyJaxbBean {
    public String name;
    public int age;

    public MyJaxbBean() {} // JAXB needs this

    public MyJaxbBean(String name, int age) {
        this.name = name;
        this.age = age;
    }
}</programlisting>
                    </example>

                    Using the above JAXB bean for producing JSON data format from you resource method, is then as simple as:

                    <example>
                        <title>JAXB bean used to generate JSON representation</title>
                        <programlisting language="java" linenumbering="numbered">@GET
@Produces("application/json")
public MyJaxbBean getMyBean() {
    return new MyJaxbBean("Agamemnon", 32);
}</programlisting>
                    </example>

                    Notice, that JSON specific mime type is specified in &lit.jaxrs.Produces; annotation, and the method returns
                    an instance of <literal>MyJaxbBean</literal>, which JAXB is able to process. Resulting JSON in this case
                    would look like:

                    <programlisting language="text" linenumbering="unnumbered">{"name":"Agamemnon", "age":"32"}</programlisting>
                </para>
                <para>
                    A proper use of JAXB annotations itself enables you to control output JSON format to certain extent.
                    Specifically, renaming and omitting items is easy to do directly just by using JAXB annotations.
                    For example, the following example depicts changes in the above mentioned MyJaxbBean that will result in
                    <literal>{"king":"Agamemnon"}</literal> JSON output.

                    <example>
                        <title>Tweaking JSON format using JAXB</title>
                        <programlisting language="java" linenumbering="numbered">@XmlRootElement
public class MyJaxbBean {

    @XmlElement(name="king")
    public String name;

    @XmlTransient
    public int age;

    // several lines removed
}</programlisting>
                    </example>
                </para>

                <para>Media modules that support this approach are &link.moxy;, &link.jackson;, &link.jettison;</para>
            </section>

            <section xml:id="json-lowlevel">
                <title>Low-level based JSON support</title>

                <para>
                    JSON Processing API is a new standard API for parsing and processing JSON structures in similar way to what
                    SAX and StAX parsers provide for XML. The API is part of Java EE 7 and later (including Jakarta EE 8).
                    Another such JSON parsing/processing API is provided by Jettison framework. Both APIs provide a low-level
                    access to producing and consuming JSON data structures. By adopting this low-level approach you would
                    be working with
                    <literal>JsonObject</literal> (or <literal>JSONObject</literal> respectively) and/or
                    <literal>JsonArray</literal> (or <literal>JSONArray</literal> respectively) classes when processing your
                    JSON data representations.
                </para>

                <para>
                    The biggest advantage of these low-level APIs is that you will gain full control over the JSON format
                    produced and consumed. You will also be able to produce and consume very large JSON structures using
                    streaming JSON parser/generator APIs.
                    On the other hand, dealing with your data model objects will probably be a lot more complex, compared
                    to the POJO or JAXB based binding approach. Differences are depicted at the following code snippets.
                </para>

                <para>
                    Let's start with JAXB-based approach.

                    <example>
                        <title>JAXB bean creation</title>
                        <programlisting language="java" linenumbering="numbered">MyJaxbBean myBean = new MyJaxbBean("Agamemnon", 32);</programlisting>
                    </example>

                    Above you construct a simple JAXB bean, which could be written in JSON as
                    <literal>{"name":"Agamemnon", "age":32}</literal>
                </para>

                <para>
                    Now to build an equivalent <literal>JsonObject</literal>/<literal>JSONObject</literal> (in terms of
                    resulting JSON expression), you would need several more lines of code. The following example illustrates
                    how to construct the same JSON data using the standard Jakarta EE 8 JSON-Processing API.
                    <example>
                        <title>Constructing a <literal>JsonObject</literal> (JSON-Processing)</title>
                        <programlisting language="java" linenumbering="numbered">JsonObject myObject = Json.createObjectBuilder()
        .add("name", "Agamemnon")
        .add("age", 32)
        .build();</programlisting>
                    </example>

                    And at last, here's how the same work can be done with Jettison API.
                    <example>
                        <title>Constructing a <literal>JSONObject</literal> (Jettison)</title>
                        <programlisting language="java" linenumbering="numbered">JSONObject myObject = new JSONObject();
try {
    myObject.put("name", "Agamemnon");
    myObject.put("age", 32);
} catch (JSONException ex) {
    LOGGER.log(Level.SEVERE, "Error ...", ex);
}</programlisting>
                    </example>
                </para>
                <para>
                    Media modules that support the low-level JSON parsing and generating approach are &link.json-p;
                    and &link.jettison;. Unless you have a strong reason for using the non-standard &link.jettison; API,
                    we recommend you to use the new standard &link.json-p; API instead.
                </para>
            </section>
        </section>

        <section xml:id="json.moxy">
            <title>MOXy</title>

            <section>
                <title>Dependency</title>

                <para>
                    To use MOXy as your JSON provider you need to add &lit.jersey-media-moxy; module to your &lit.pom.xml; file:

                    <programlisting language="xml" linenumbering="unnumbered">&lt;dependency&gt;
    &lt;groupId&gt;org.glassfish.jersey.media&lt;/groupId&gt;
    &lt;artifactId&gt;jersey-media-moxy&lt;/artifactId&gt;
    &lt;version&gt;&version;&lt;/version&gt;
&lt;/dependency&gt;</programlisting>

                    If you're not using Maven make sure to have all needed dependencies (see &jersey.media.moxy.deps.link;) on the classpath.
                </para>
            </section>
            <section xml:id="moxy-registration">
                <title>Configure and register</title>

                <para>
                    As stated in the <xref linkend="deployment.autodiscoverable"/> as well as earlier in this chapter, MOXy media
                    module is one of the modules where you don't need to explicitly register its &lit.jaxrs.core.Feature;s
                    (&lit.jersey.media.MoxyJsonFeature;) in your client/server &jaxrs.core.Configurable; as this feature is
                    automatically discovered and registered when you add &lit.jersey-media-moxy; module to your class-path.
                </para>
                <para>
                    The auto-discoverable &lit.jersey-media-moxy; module defines a few properties that can be used to control the
                    automatic registration of &lit.jersey.media.MoxyJsonFeature; (besides the generic
                    &jersey.common.CommonProperties.FEATURE_AUTO_DISCOVERY_DISABLE; an the its client/server variants):

                    <itemizedlist>
                        <listitem>
                            <para>&jersey.common.CommonProperties.MOXY_JSON_FEATURE_DISABLE;</para>
                        </listitem>
                        <listitem>
                            <para>&jersey.server.ServerProperties.MOXY_JSON_FEATURE_DISABLE;</para>
                        </listitem>
                        <listitem>
                            <para>&jersey.client.ClientProperties.MOXY_JSON_FEATURE_DISABLE;</para>
                        </listitem>
                    </itemizedlist>
                </para>
                <note>
                    <para>
                        A manual registration of any other Jersey JSON provider feature (except for &link.json-p;)
                        disables the automated enabling and configuration of &lit.jersey.media.MoxyJsonFeature;.
                    </para>
                </note>
                <para>
                    To configure &jaxrs.ext.MessageBodyReader;s / &jaxrs.ext.MessageBodyWriter;s provided by MOXy you can simply
                    create an instance of &jersey.media.MoxyJsonConfig; and set values of needed properties. For most common
                    properties you can use a particular method to set the value of the property or you can use more generic
                    methods to set the property:

                    <itemizedlist>
                        <listitem>
                            <para>
                                &jersey.media.MoxyJsonConfig.property; - sets a property value for both Marshaller and Unmarshaller.
                            </para>
                        </listitem>
                        <listitem>
                            <para>
                                &jersey.media.MoxyJsonConfig.marshallerProperty; - sets a property value for Marshaller.
                            </para>
                        </listitem>
                        <listitem>
                            <para>
                                &jersey.media.MoxyJsonConfig.unmarshallerProperty; - sets a property value for Unmarshaller.
                            </para>
                        </listitem>
                    </itemizedlist>

                    <example>
                        <title>&jersey.media.MoxyJsonConfig; - Setting properties.</title>

                        <programlisting language="java">final Map&lt;String, String&gt; namespacePrefixMapper = new HashMap&lt;String, String&gt;();
namespacePrefixMapper.put("http://www.w3.org/2001/XMLSchema-instance", "xsi");

final MoxyJsonConfig configuration = new MoxyJsonConfig()
        .setNamespacePrefixMapper(namespacePrefixMapper)
        .setNamespaceSeparator(':');
                        </programlisting>
                    </example>

                    In order to make &lit.jersey.media.MoxyJsonConfig; visible for MOXy you need to create and register
                    &lit.jaxrs.ext.ContextResolver; in your client/server code.

                    <example>
                        <title>Creating <literal>ContextResolver&lt;MoxyJsonConfig&gt;</literal></title>

                        <programlisting language="java">final Map&lt;String, String&gt; namespacePrefixMapper = new HashMap&lt;String, String&gt;();
namespacePrefixMapper.put("http://www.w3.org/2001/XMLSchema-instance", "xsi");

final MoxyJsonConfig moxyJsonConfig = MoxyJsonConfig()
            .setNamespacePrefixMapper(namespacePrefixMapper)
            .setNamespaceSeparator(':');

final ContextResolver&lt;MoxyJsonConfig&gt; jsonConfigResolver = moxyJsonConfig.resolver();
</programlisting>
                    </example>
                </para>

                <para>
                    Another way to pass configuration properties to the underlying <literal>MOXyJsonProvider</literal> is to set
                    them directly into your &jaxrs.core.Configurable; instance (see an example below). These are overwritten by
                    properties set into the &jersey.media.MoxyJsonConfig;.

                    <example>
                        <title>Setting properties for MOXy providers into &jaxrs.core.Configurable;</title>

                        <programlisting language="java">new ResourceConfig()
                            .property(MarshallerProperties.JSON_NAMESPACE_SEPARATOR, ".")
                            // further configuration</programlisting>
                    </example>
                </para>

                <para>
                    There are some properties for which Jersey sets the default value when
                    &jaxrs.ext.MessageBodyReader; / &jaxrs.ext.MessageBodyWriter; from MOXy is used and they are:

                    <table frame="all">
                        <title>Default property values for MOXy &jaxrs.ext.MessageBodyReader; / &jaxrs.ext.MessageBodyWriter;</title>
                        <tgroup cols="2" align="left">
                            <tbody>
                                <row>
                                    <entry><literal>javax.xml.bind.Marshaller#JAXB_FORMATTED_OUTPUT</literal></entry>
                                    <entry><literal>false</literal></entry>
                                </row>
                                <row>
                                    <entry>
                                        <literal>org.eclipse.persistence.jaxb.JAXBContextProperties#JSON_INCLUDE_ROOT</literal>
                                    </entry>
                                    <entry><literal>false</literal></entry>
                                </row>
                                <row>
                                    <entry>
                                        <literal>org.eclipse.persistence.jaxb.MarshallerProperties#JSON_MARSHAL_EMPTY_COLLECTIONS</literal>
                                    </entry>
                                    <entry><literal>true</literal></entry>
                                </row>
                                <row>
                                    <entry>
                                        <literal>org.eclipse.persistence.jaxb.JAXBContextProperties#JSON_NAMESPACE_SEPARATOR</literal>
                                    </entry>
                                    <entry><literal>org.eclipse.persistence.oxm.XMLConstants#DOT</literal></entry>
                                </row>
                            </tbody>
                        </tgroup>
                    </table>
                </para>

                <example xml:id="ex-moxy-client">
                    <title>Building client with MOXy JSON feature enabled.</title>

                    <programlisting language="java">final Client client = ClientBuilder.newBuilder()
        // The line below that registers MOXy feature can be
        // omitted if FEATURE_AUTO_DISCOVERY_DISABLE is
        // not disabled.
        .register(MoxyJsonFeature.class)
        .register(jsonConfigResolver)
        .build();</programlisting>
                </example>

                <example xml:id="ex-moxy-server">
                    <title>Creating JAX-RS application with MOXy JSON feature enabled.</title>

                    <programlisting language="java">// Create JAX-RS application.
final Application application = new ResourceConfig()
        .packages("org.glassfish.jersey.examples.jsonmoxy")
        // The line below that registers MOXy feature can be
        // omitted if FEATURE_AUTO_DISCOVERY_DISABLE is
        // not disabled.
        .register(MoxyJsonFeature.class)
        .register(jsonConfigResolver);</programlisting>
                </example>
            </section>

            <section>
                <title>Examples</title>

                <para>
                    Jersey provides a <link xlink:href='&jersey.github.examples.uri;/json-moxy'>JSON MOXy example</link>
                    on how to use MOXy to consume/produce JSON.
                </para>
            </section>
        </section>

        <section xml:id="json.json-p">
            <title>Java API for JSON Processing (JSON-P)</title>

            <section>
                <title>Dependency</title>

                <para>
                    To use JSON-P as your JSON provider you need to add &lit.jersey-media-json-processing; module to your
                    &lit.pom.xml; file:

                    <programlisting language="xml" linenumbering="unnumbered">&lt;dependency&gt;
    &lt;groupId&gt;org.glassfish.jersey.media&lt;/groupId&gt;
    &lt;artifactId&gt;jersey-media-json-processing&lt;/artifactId&gt;
    &lt;version&gt;&version;&lt;/version&gt;
&lt;/dependency&gt;</programlisting>

                    If you're not using Maven make sure to have all needed dependencies (see &jersey.media.json-processing.deps.link;)
                    on the class-path.
                </para>
            </section>
            <section xml:id="jsonp-registration">
                <title>Configure and register</title>

                <para>
                    As stated in <xref linkend="deployment.autodiscoverable"/> JSON-Processing media module is one of the
                    modules where you don't need to explicitly register its
                    &lit.jaxrs.core.Feature;s (&lit.jersey.media.JsonProcessingFeature;) in your client/server
                    &jaxrs.core.Configurable; as this feature is automatically discovered and registered when you add
                    &lit.jersey-media-json-processing; module to your classpath.
                </para>
                <para>
                    As for the other modules, &lit.jersey-media-json-processing; has also few properties that can affect the
                    registration of &lit.jersey.media.JsonProcessingFeature;
                    (besides &jersey.common.CommonProperties.FEATURE_AUTO_DISCOVERY_DISABLE; and the like):

                    <itemizedlist>
                        <listitem>
                            <para>&jersey.common.CommonProperties.JSON_PROCESSING_FEATURE_DISABLE;</para>
                        </listitem>
                        <listitem>
                            <para>&jersey.server.ServerProperties.JSON_PROCESSING_FEATURE_DISABLE;</para>
                        </listitem>
                        <listitem>
                            <para>&jersey.client.ClientProperties.JSON_PROCESSING_FEATURE_DISABLE;</para>
                        </listitem>
                    </itemizedlist>
                </para>
                <para>
                    To configure &jaxrs.ext.MessageBodyReader;s / &jaxrs.ext.MessageBodyWriter;s provided by JSON-P you can simply
                    add values for supported properties into the &jaxrs.core.Configuration; instance (client/server). Currently
                    supported are these properties:

                    <itemizedlist>
                        <listitem>
                            <para>
                                <literal>JsonGenerator.PRETTY_PRINTING</literal>
                                ("<literal>javax.json.stream.JsonGenerator.prettyPrinting</literal>")
                            </para>
                        </listitem>
                    </itemizedlist>
                </para>

                <example>
                    <title>Building client with JSON-Processing JSON feature enabled.</title>

                    <programlisting language="java">ClientBuilder.newClient(new ClientConfig()
        // The line below that registers JSON-Processing feature can be
        // omitted if FEATURE_AUTO_DISCOVERY_DISABLE is not disabled.
        .register(JsonProcessingFeature.class)
        .property(JsonGenerator.PRETTY_PRINTING, true)
);</programlisting>
                </example>

                <example>
                    <title>Creating JAX-RS application with JSON-Processing JSON feature enabled.</title>

                    <programlisting language="java">// Create JAX-RS application.
final Application application = new ResourceConfig()
        // The line below that registers JSON-Processing feature can be
        // omitted if FEATURE_AUTO_DISCOVERY_DISABLE is not disabled.
        .register(JsonProcessingFeature.class)
        .packages("org.glassfish.jersey.examples.jsonp")
        .property(JsonGenerator.PRETTY_PRINTING, true);</programlisting>
                </example>
            </section>

            <section>
                <title>Examples</title>

                <para>Jersey provides a
                    <link xlink:href='&jersey.github.examples.uri;/json-processing-webapp'>JSON Processing example</link>
                    on how to use JSON-Processing to consume/produce JSON.</para>
            </section>
        </section>
        <section xml:id="json.jackson">
            <title>Jackson (1.x and 2.x)</title>

            <section>
                <title>Dependency</title>

                <para>
                    To use Jackson 2.x as your JSON provider you need to add &lit.jersey-media-json-jackson; module to your
                    &lit.pom.xml; file:

                    <programlisting language="xml" linenumbering="unnumbered">&lt;dependency&gt;
    &lt;groupId&gt;org.glassfish.jersey.media&lt;/groupId&gt;
    &lt;artifactId&gt;jersey-media-json-jackson&lt;/artifactId&gt;
    &lt;version&gt;&version;&lt;/version&gt;
&lt;/dependency&gt;</programlisting>

                    To use Jackson 1.x it'll look like:

                    <programlisting language="xml" linenumbering="unnumbered">&lt;dependency&gt;
    &lt;groupId&gt;org.glassfish.jersey.media&lt;/groupId&gt;
    &lt;artifactId&gt;jersey-media-json-jackson1&lt;/artifactId&gt;
    &lt;version&gt;&version;&lt;/version&gt;
&lt;/dependency&gt;</programlisting>

                    If you're not using Maven make sure to have all needed dependencies (see &jersey.media.json-jackson.deps.link; or
                    &jersey.media.json-jackson1.deps.link;) on the classpath.
                </para>
            </section>
            <section xml:id="jackson-registration">
                <title>Configure and register</title>

                <note>
                    <para>
                        Note that there is a difference in namespaces between Jackson 1.x (<literal>org.codehaus.jackson</literal>)
                        and Jackson 2.x (<literal>com.fasterxml.jackson</literal>).
                    </para>
                </note>

                <para>
                    Jackson JSON processor could be controlled via providing a custom Jackson 2 &jersey.media.ObjectMapper; (or
                    &jersey.media.ObjectMapper1; for Jackson 1) instance.
                    This could be handy if you need to redefine the default Jackson behaviour and to fine-tune how your JSON data
                    structures look like. Detailed description of all Jackson features is out of scope of this guide. The example
                    below gives you a hint on how to wire your &lit.jersey.media.ObjectMapper; (&jersey.media.ObjectMapper1;)
                    instance into your Jersey application.
                </para>

                <para>
                    Since the 2.36 version of Jersey it is possible to filter (include/exclude) Jackson modules by properties
                    &jersey.common.CommonProperties.JSON_JACKSON_DISABLED_MODULES; and &jersey.common.CommonProperties.JSON_JACKSON_ENABLED_MODULES;
                    (with their client/server derivatives). If the &jersey.common.CommonProperties.JSON_JACKSON_ENABLED_MODULES; property is used,
                    only those named modules will be used for JSON processing. On the other hand if the &jersey.common.CommonProperties.JSON_JACKSON_DISABLED_MODULES;
                    property is used, those listed modules will be explicitly excluded from processing while other (not listed) will remain. Please note that
                    the <literal>JaxbAnnotationModule</literal> module is always excluded from processing and this is not configurable.
                </para>

                <para>
                    In order to use Jackson as your JSON (JAXB/POJO) provider you need to register &jersey.media.JacksonFeature;
                    (&jersey.media.Jackson1Feature;) and a &lit.jaxrs.ext.ContextResolver; for &lit.jersey.media.ObjectMapper;,
                    if needed, in your &jaxrs.core.Configurable; (client/server).

                    <example>
                        <title><literal>ContextResolver&lt;ObjectMapper&gt;</literal></title>

                        <programlisting language="java" linenumbering="numbered">@Provider
public class MyObjectMapperProvider implements ContextResolver&lt;ObjectMapper&gt; {

    final ObjectMapper defaultObjectMapper;

    public MyObjectMapperProvider() {
        defaultObjectMapper = createDefaultMapper();
    }

    @Override
    public ObjectMapper getContext(Class&lt;?&gt; type) {
            return defaultObjectMapper;
        }
    }

    private static ObjectMapper createDefaultMapper() {
        final ObjectMapper result = new ObjectMapper();
        result.configure(Feature.INDENT_OUTPUT, true);

        return result;
    }

    // ...
}</programlisting>
<para>To view the complete example source code, see
    <link xlink:href='&jersey.github.examples.uri;/json-jackson/src/main/java/org/glassfish/jersey/examples/jackson/MyObjectMapperProvider.java'>
    MyObjectMapperProvider</link> class from the
    <link xlink:href='&jersey.github.examples.uri;/json-jackson'>JSON-Jackson</link> example.</para>
                    </example>

                    <example>
                        <title>Building client with Jackson JSON feature enabled.</title>

                        <programlisting language="java" linenumbering="numbered">final Client client = ClientBuilder.newBuilder()
        .register(MyObjectMapperProvider.class)  // No need to register this provider if no special configuration is required.
        .register(JacksonFeature.class)
        .build();</programlisting>
                    </example>

                    <example>
                        <title>Creating JAX-RS application with Jackson JSON feature enabled.</title>

                        <programlisting language="java" linenumbering="numbered">// Create JAX-RS application.
final Application application = new ResourceConfig()
        .packages("org.glassfish.jersey.examples.jackson")
        .register(MyObjectMapperProvider.class)  // No need to register this provider if no special configuration is required.
        .register(JacksonFeature.class);</programlisting>
                    </example>
                </para>
            </section>

            <section>
                <title>Examples</title>

                <para>
                    Jersey provides <link xlink:href='&jersey.github.examples.uri;/json-jackson'>JSON Jackson (2.x) example</link>
                    and <link xlink:href='&jersey.github.examples.uri;/json-jackson1'>JSON Jackson (1.x) example</link> showing
                    how to use Jackson to consume/produce JSON.
                </para>
            </section>
        </section>

        <section xml:id="json.jettison">
            <title>Jettison</title>

            <para>
                JAXB approach for (de)serializing JSON in Jettison module provides, in addition to using pure JAXB,
                configuration options that could be set on an &jersey.media.JettisonConfig; instance. The instance could be then
                further used to create a &jersey.media.JettisonJaxbContext;, which serves as a main configuration point in this
                area.
                To pass your specialized &lit.jersey.media.JettisonJaxbContext; to Jersey, you will finally need to implement
                a JAXBContext &jaxrs.ext.ContextResolver; (see below).
            </para>

            <section>
                <title>Dependency</title>

                <para>
                    To use Jettison as your JSON provider you need to add &lit.jersey-media-json-jettison; module to your
                    &lit.pom.xml; file:

                    <programlisting language="xml" linenumbering="unnumbered">&lt;dependency&gt;
    &lt;groupId&gt;org.glassfish.jersey.media&lt;/groupId&gt;
    &lt;artifactId&gt;jersey-media-json-jettison&lt;/artifactId&gt;
    &lt;version&gt;&version;&lt;/version&gt;
&lt;/dependency&gt;</programlisting>

                    If you're not using Maven make sure to have all needed dependencies (see &jersey.media.json-jettison.deps.link;) on
                    the classpath.
                </para>
            </section>
            <section>
                <title>JSON Notations</title>

                <para>
                    &lit.jersey.media.JettisonConfig; allows you to use two JSON notations. Each of these notations serializes
                    JSON in a different way. Following is a list of supported notations:

                    <itemizedlist>
                        <listitem>
                            <para>JETTISON_MAPPED (default notation)</para>
                        </listitem>
                        <listitem>
                            <para>BADGERFISH</para>
                        </listitem>
                    </itemizedlist>

                    You might want to use one of these notations, when working with more complex XML documents. Namely when you
                    deal with multiple XML namespaces in your JAXB beans.
                </para>

                <para>
                    Individual notations and their further configuration options are described below. Rather then explaining
                    rules for mapping XML constructs into JSON, the notations will be described using a simple example. Following
                    are JAXB beans, which will be used.

                    <example>
                        <title>JAXB beans for JSON supported notations description, simple address bean</title>

                        <programlisting language="java" linenumbering="numbered">@XmlRootElement
public class Address {
    public String street;
    public String town;

    public Address(){}

    public Address(String street, String town) {
        this.street = street;
        this.town = town;
    }
}</programlisting>
                    </example>

                    <example>
                        <title>JAXB beans for JSON supported notations description, contact bean</title>

                        <programlisting language="java" linenumbering="numbered">@XmlRootElement
public class Contact {

    public int id;
    public String name;
    public List&lt;Address&gt; addresses;

    public Contact() {};

    public Contact(int id, String name, List&lt;Address&gt; addresses) {
        this.name = name;
        this.id = id;
        this.addresses =
            (addresses != null) ? new LinkedList&lt;Address&gt;(addresses) : null;
    }
}</programlisting>
                    </example>
                </para>

                <para>
                    Following text will be mainly working with a contact bean initialized with:

                    <example>
                        <title>JAXB beans for JSON supported notations description, initialization</title>
                        <programlisting language="java"  linenumbering="numbered">Address[] addresses = {new Address("Long Street 1", "Short Village")};
Contact contact = new Contact(2, "Bob", Arrays.asList(addresses));</programlisting>
                    </example>

                    I.e. contact bean with <literal>id=2</literal>, <literal>name="Bob"</literal> containing
                    a single address (<literal>street="Long Street 1"</literal>, <literal>town="Short Village"</literal>).
                </para>

                <para>
                    All below described configuration options are documented also in api-docs at &jersey.media.JettisonConfig;.
                </para>

                <section>
                    <title>Jettison mapped notation</title>

                    <para>
                        If you need to deal with various XML namespaces, you will find Jettison <literal>mapped</literal>
                        notation pretty useful. Lets define a particular namespace for <code>id</code> item:

                        <programlisting language="java" linenumbering="numbered">...
@XmlElement(namespace="http://example.com")
public int id;
...</programlisting>

                        Then you simply configure a mapping from XML namespace into JSON prefix as follows:

                        <example xml:id="json.jaxb.jettison.mapped.ns.def">
                            <title>
                                XML namespace to JSON mapping configuration for Jettison based <literal>mapped</literal> notation
                            </title>

                            <programlisting language="java" linenumbering="numbered">Map&lt;String,String&gt; ns2json = new HashMap&lt;String, String&gt;();
ns2json.put("http://example.com", "example");
context = new JettisonJaxbContext(
    JettisonConfig.mappedJettison().xml2JsonNs(ns2json).build(),
    types);</programlisting>
                        </example>

                        Resulting JSON will look like in the example below.

                        <example>
                            <title>JSON expression with XML namespaces mapped into JSON</title>
                            <programlisting language="xml" linenumbering="numbered">{
   "contact":{
      "example.id":2,
      "name":"Bob",
      "addresses":{
         "street":"Long Street 1",
         "town":"Short Village"
      }
   }
}</programlisting>
                        </example>

                        Please note, that <code>id</code> item became <code>example.id</code> based on the XML namespace mapping.
                        If you have more XML namespaces in your XML, you will need to configure appropriate mapping for all of
                        them.
                    </para>
                    <para>
                        Another configurable option introduced in Jersey version 2.2 is related to serialization of JSON arrays with Jettison's
                        mapped notation. When serializing elements representing single item lists/arrays, you might want to utilise
                        the following Jersey configuration method to explicitly name which elements to treat as arrays no matter what the actual content is.

                        <example xml:id="json.jaxb.jettison.mapped.array.def">
                            <title>
                                JSON Array configuration for Jettison based <literal>mapped</literal> notation
                            </title>

                            <programlisting language="java" linenumbering="numbered">context = new JettisonJaxbContext(
    JettisonConfig.mappedJettison().serializeAsArray("name").build(),
    types);</programlisting>
                        </example>

                        Resulting JSON will look like in the example below, unimportant lines removed for sanity.

                        <example>
                            <title>JSON expression with JSON arrays explicitly configured via Jersey</title>
                            <programlisting language="xml" linenumbering="numbered">{
   "contact":{
      ...
      "name":["Bob"],
      ...
   }
}</programlisting>
                        </example>

                    </para>
                </section>

                <section>
                    <title>Badgerfish notation</title>

                    <para>
                        From JSON and JavaScript perspective, this notation is definitely the worst readable one.
                        You will probably not want to use it, unless you need to make sure your JAXB beans could be flawlessly
                        written and read back to and from JSON, without bothering with any formatting configuration, namespaces,
                        etc.
                    </para>

                    <para>
                        &lit.jersey.media.JettisonConfig; instance using <literal>badgerfish</literal> notation could be built
                        with

                        <programlisting language="java">JettisonConfig.badgerFish().build()</programlisting>

                        and the JSON output JSON will be as follows.

                        <example>
                            <title>JSON expression produced using <literal>badgerfish</literal> notation</title>
                            <programlisting language="xml" linenumbering="numbered">{
   "contact":{
      "id":{
         "$":"2"
      },
      "name":{
         "$":"Bob"
      },
      "addresses":{
         "street":{
            "$":"Long Street 1"
         },
         "town":{
            "$":"Short Village"
         }
      }
   }
}</programlisting>
                        </example>
                    </para>
                </section>
            </section>

            <section xml:id="jettison-registration">
                <title>Configure and register</title>

                <para>
                    In order to use Jettison as your JSON (JAXB/POJO) provider you need to register &jersey.media.JettisonFeature;
                    and a &lit.jaxrs.ext.ContextResolver; for &lit.jaxb.JAXBContext; (if needed) in your &jaxrs.core.Configurable;
                    (client/server).

                    <example>
                        <title><literal>ContextResolver&lt;ObjectMapper&gt;</literal></title>

                        <programlisting language="java">@Provider
public class JaxbContextResolver implements ContextResolver&lt;JAXBContext&gt; {

    private final JAXBContext context;
    private final Set&lt;Class&lt;?&gt;&gt; types;
    private final Class&lt;?&gt;[] cTypes = {Flights.class, FlightType.class, AircraftType.class};

    public JaxbContextResolver() throws Exception {
        this.types = new HashSet&lt;Class&lt;?&gt;&gt;(Arrays.asList(cTypes));
        this.context = new JettisonJaxbContext(JettisonConfig.DEFAULT, cTypes);
    }

    @Override
    public JAXBContext getContext(Class&lt;?&gt; objectType) {
        return (types.contains(objectType)) ? context : null;
    }
}</programlisting>
                    </example>

                    <example>
                        <title>Building client with Jettison JSON feature enabled.</title>

                        <programlisting language="java">final Client client = ClientBuilder.newBuilder()
        .register(JaxbContextResolver.class)  // No need to register this provider if no special configuration is required.
        .register(JettisonFeature.class)
        .build();</programlisting>
                    </example>

                    <example>
                        <title>Creating JAX-RS application with Jettison JSON feature enabled.</title>

                        <programlisting language="java">// Create JAX-RS application.
final Application application = new ResourceConfig()
        .packages("org.glassfish.jersey.examples.jettison")
        .register(JaxbContextResolver.class)  // No need to register this provider if no special configuration is required.
        .register(JettisonFeature.class);</programlisting>
                    </example>
                </para>
            </section>

            <section>
                <title>Examples</title>

                <para>
                    Jersey provides an <link xlink:href='&jersey.github.examples.uri;/json-jettison'>JSON Jettison example</link>
                    on how to use Jettison to consume/produce JSON.
                </para>
            </section>
        </section>

        <section>
            <title><literal>@JSONP</literal> - JSON with Padding Support</title>

            <para>
                Jersey provides out-of-the-box support for <link xlink:href='&wikipedia.uri;JSONP'>JSONP</link>
                - JSON with padding. The following conditions has to be met to take advantage of this capability:

                <itemizedlist>
                    <listitem>
                        <para>
                            Resource method, which should return wrapped JSON, needs to be annotated with &jersey.server.JSONP;
                            annotation.
                        </para>
                    </listitem>
                    <listitem>
                        <para>
                            &jaxrs.ext.MessageBodyWriter; for <literal>application/json</literal> media type, which also accepts
                            the return type of the resource method, needs to be registered (see <link linkend="json">JSON</link>
                            section of this chapter).
                        </para>
                    </listitem>
                    <listitem>
                        <para>
                            User's request has to contain &lit.http.header.Accept; header with one of the JavaScript media types
                            defined (see below).
                        </para>
                    </listitem>
                </itemizedlist>

                Acceptable media types compatible with &lit.jersey.server.JSONP; are: <literal>application/javascript</literal>,
                <literal>application/x-javascript</literal>, <literal>application/ecmascript</literal>,
                <literal>text/javascript</literal>, <literal>text/x-javascript</literal>, <literal>text/ecmascript</literal>,
                <literal>text/jscript</literal>.

                <example>
                    <title>Simplest case of using &lit.jersey.server.JSONP;</title>

                    <programlisting language="java">@GET
@JSONP
@Produces({"application/json", "application/javascript"})
public JaxbBean getSimpleJSONP() {
    return new JaxbBean("jsonp");
}</programlisting>
                </example>

                Assume that we have registered a JSON providers and that the <literal>JaxbBean</literal> looks like:

                <example>
                    <title>JaxbBean for @JSONP example</title>

                    <programlisting language="java">@XmlRootElement
public class JaxbBean {

    private String value;

    public JaxbBean() {}

    public JaxbBean(final String value) {
        this.value = value;
    }

    public String getValue() {
        return value;
    }

    public void setValue(final String value) {
        this.value = value;
    }
}</programlisting>
                </example>

                When you send a &lit.http.GET; request with &lit.http.header.Accept; header set to
                <literal>application/javascript</literal> you'll get a result entity that look like:

                <programlisting language="xml">callback({
    "value" : "jsonp",
})</programlisting>
            </para>

            <para>
                There are, of course, ways to configure wrapping method of the returned entity which defaults to
                <literal>callback</literal> as you can see in the previous example.
                &lit.jersey.server.JSONP; has two parameters that can be configured: <literal>callback</literal> and
                <literal>queryParam</literal>.
                <literal>callback</literal> stands for the name of the JavaScript callback function defined by the application.
                The second parameter, <literal>queryParam</literal>, defines the name of the query parameter holding the name of
                the callback function to be used (if present in the request). Value of <literal>queryParam</literal> defaults to
                <literal>__callback</literal> so even if you do not set the name of the query parameter yourself, client can
                always affect the result name of the wrapping JavaScript callback method.

                <note>
                    <para>
                        <literal>queryParam</literal> value (if set) always takes precedence over <literal>callback</literal>
                        value.
                    </para>
                </note>
            </para>

            <para>
                Lets modify our example a little bit:

                <example>
                    <title>Example of &lit.jersey.server.JSONP; with configured parameters.</title>

                    <programlisting language="java">@GET
@Produces({"application/json", "application/javascript"})
@JSONP(callback = "eval", queryParam = "jsonpCallback")
public JaxbBean getSimpleJSONP() {
    return new JaxbBean("jsonp");
}</programlisting>
                </example>

                And make two requests:

                <programlisting>curl -X GET http://localhost:8080/jsonp</programlisting>

                will return

                <programlisting language="xml">eval({
    "value" : "jsonp",
})</programlisting>

                and the

                <programlisting>curl -X GET http://localhost:8080/jsonp?jsonpCallback=alert</programlisting>

                will return

                <programlisting language="xml">alert({
    "value" : "jsonp",
})</programlisting>
            </para>

            <formalpara>
                <title>Example</title>
                <para>
                    You can take a look at a provided
                    <link xlink:href='&jersey.github.examples.uri;/json-with-padding'>JSON with Padding example</link>.
                </para>
            </formalpara>
        </section>
        <section xml:id="json.json-b">
            <title>Java API for JSON Binding (JSON-B)</title>

            <para>
                Jersey uses &yasson.link; for JSON Binding (JSR-367) implementation.
            </para>
            <section>
                <title>Dependency</title>
                <para>
                    To use JSON-B as your JSON provider you need to add &lit.jersey-media-json-binding; module to your
                    &lit.pom.xml; file:

                    <programlisting language="xml" linenumbering="unnumbered">&lt;dependency&gt;
    &lt;groupId&gt;org.glassfish.jersey.media&lt;/groupId&gt;
    &lt;artifactId&gt;jersey-media-json-binding&lt;/artifactId&gt;
    &lt;version&gt;&version;&lt;/version&gt;
&lt;/dependency&gt;</programlisting>

                    If you're not using Maven make sure to have all needed dependencies
                    (see &jersey.media.json-binding.deps.link;) on the classpath.
                </para>
            </section>

            <section xml:id="json.jsonb-registration">
                <title>Configure and register</title>

                <para>
                    As stated in <xref linkend="deployment.autodiscoverable"/> JSON-Binding media module is one of the
                    modules where you don't need to explicitly register its
                    &lit.jaxrs.core.Feature;s (&lit.jersey.media.JsonBindingFeature;) in your client/server
                    &jaxrs.core.Configurable; as this feature is automatically discovered and registered when you add
                    &lit.jersey-media-json-binding; module to your classpath.
                </para>
                <para>
                    To use custom preconfigured JSON-B, it is simply possible to register
                    a &lit.jaxrs.ext.ContextResolver; for &lit.jsonb.Jsonb; in your &jaxrs.core.Configurable;
                    (client/server) and configure &jsonb.JsonbConfig;.
                </para>

                <example>
                    <title><literal>ContextResolver&lt;Jsonb&gt;</literal></title>

                    <programlisting language="java">@Provider
public class JsonbContextResolver implements ContextResolver&lt;Jsonb&gt; {

        @Override
        public Jsonb getContext(Class&gt;?&lt; type) {
            JsonbConfig config = new JsonbConfig();
            // configure JsonbConfig
            ...
            return JsonbBuilder.create(config);
        }
}</programlisting>
            </example>
            <example>
                    <title><literal>Register the feature and ContextResolver&lt;Jsonb></literal></title>
                    <programlisting language="java">ClientBuilder.newClient(new ClientConfig()
    // The line below that registers JSON-Binding feature can be
    // omitted if FEATURE_AUTO_DISCOVERY_DISABLE is not disabled.
    .register(JsonBindingFeature.class)
    .register(JsonbContextResolver.class)
);</programlisting>
                </example>

                <formalpara>
                    <title>Example</title>
                    <para>
                        You can take a look at a provided
                        <link xlink:href='&jersey.github.examples.uri;/json-binding-webapp'>JSON-B example.</link>.
                    </para>
                </formalpara>
            </section>
        </section>
        <section xml:id="json.configuration">
            <title>Properties for configuring JSON providers</title>

            <para>
                Apart from using &lit.jaxrs.ext.ContextResolver; for configuring directly the specific JSON provider classes,
                Jersey supports additional configuration properties prefixed by <literal>JSON</literal> that are available in
                <xref linkend="appendix-properties-message">the appendix.</xref>
            </para>
        </section>
    </section>

    <section xml:id="xml">
        <title>XML</title>

        <para>
            As you probably already know, Jersey uses &lit.jaxrs.ext.MessageBodyWriter;s and &lit.jaxrs.ext.MessageBodyReader;s to
            parse incoming requests and create outgoing responses. Every user can create its own representation but... this is not
            recommended way how to do things. XML is proven standard for interchanging information, especially in web services.
            Jerseys supports low level data types used for direct manipulation and JAXB XML entities.
        </para>

        <section>
            <title xml:id="xml.lowlevel">Low level XML support</title>

            <para>
                Jersey currently support several low level data types: &jdk7.StreamSource;, &jdk7.SAXSource;, &jdk7.DOMSource;
                and &jdk7.org.w3c.dom.Document;. You can use these types as the return type or as a method (resource) parameter.
                Lets say we want to test this feature and we have
                <link xlink:href='&jersey.github.examples.uri;/helloworld'>helloworld example</link> as a starting point.
                All we need to do is add methods (resources) which consumes and produces XML and types mentioned above will be
                used.
            </para>

            <example>
                <title>Low level XML test - methods added to <literal>HelloWorldResource.java</literal></title>
                <programlisting language="java" linenumbering="numbered">@POST
@Path("StreamSource")
public StreamSource getStreamSource(StreamSource streamSource) {
    return streamSource;
}

@POST
@Path("SAXSource")
public SAXSource getSAXSource(SAXSource saxSource) {
    return saxSource;
}

@POST
@Path("DOMSource")
public DOMSource getDOMSource(DOMSource domSource) {
    return domSource;
}

@POST
@Path("Document")
public Document getDocument(Document document) {
    return document;
}</programlisting>
            </example>

            <para>
                Both &lit.jaxrs.ext.MessageBodyWriter; and &lit.jaxrs.ext.MessageBodyReader; are used in this case, all we need is
                a &lit.http.POST; request with some XML document as a request entity. To keep this as simple as possible only root
                element with no content will be sent: <literal>"&lt;test /&gt;"</literal>. You can create JAX-RS client to do that
                or use some other tool, for example <literal>curl</literal>:
                <informalexample>
                    <programlisting>curl -v http://localhost:8080/base/helloworld/StreamSource -d "&lt;test/&gt;"</programlisting>
                </informalexample>
                You should get exactly the same XML from our service as is present in the request; in this case, XML headers are
                added to response but content stays. Feel free to iterate through all resources.
            </para>
        </section>

        <section>
            <title xml:id="xml.jaxb.xmlRootElement">Getting started with JAXB</title>

            <para>
                Good start for people which already have some experience with JAXB annotations
                is <link xlink:href='&jersey.github.examples.uri;/jaxb'>JAXB example</link>. You can see various use-cases there.
                This text is mainly meant for those who don't have prior experience with JAXB. Don't expect that all possible
                annotations and their combinations will be covered in this chapter,
                <link xlink:href='http://jaxb.java.net'>JAXB (JSR 222 implementation)</link>
                is pretty complex and comprehensive. But if you just want to know how you can interchange XML messages with your
                REST service, you are looking at the right chapter.
            </para>

            <para>
                Lets start with simple example. Lets say we have class <literal>Planet</literal> and service which produces
                "Planets".
            </para>

            <example>
                <title>Planet class</title>
                <programlisting language="java" linenumbering="numbered">@XmlRootElement
public class Planet {
    public int id;
    public String name;
    public double radius;
}</programlisting>
            </example>

            <example>
                <title>Resource class</title>
                <programlisting language="java" linenumbering="numbered">@Path("planet")
public class Resource {

    @GET
    @Produces(MediaType.APPLICATION_XML)
    public Planet getPlanet() {
        final Planet planet = new Planet();

        planet.id = 1;
        planet.name = "Earth";
        planet.radius = 1.0;

        return planet;
    }
}</programlisting>
            </example>

            <para>
                You can see there is some extra annotation declared on <literal>Planet</literal> class, particularly
                &jaxb.annotation.XmlRootElement;. This is an JAXB annotation which maps java classes
                to XML elements. We don't need to specify anything else, because <literal>Planet</literal> is very simple class
                and all fields are public. In this case, XML element name will be derived from the class name or
                you can set the name property: <literal>@XmlRootElement(name="yourName")</literal>.
            </para>

            <para>
                Our resource class will respond to <literal>GET /planet</literal> with

                <programlisting language="xml">&lt;?xml version="1.0" encoding="UTF-8" standalone="yes"?&gt;
&lt;planet&gt;
    &lt;id&gt;1&lt;/id&gt;
    &lt;name&gt;Earth&lt;/name&gt;
    &lt;radius&gt;1.0&lt;/radius&gt;
&lt;/planet&gt;</programlisting>

                which might be exactly what we want... or not. Or we might not really care, because we
                can use JAX-RS client for making requests to this resource and this is easy as:
                <programlisting language="java" linenumbering="unnumbered">
                    Planet planet = webTarget.path("planet").request(MediaType.APPLICATION_XML_TYPE).get(Planet.class);
                </programlisting>
                There is pre-created &lit.jaxrs.client.WebTarget; object which points to our applications context root and
                we simply add path (in our case its <literal>planet</literal>), accept header (not mandatory, but service could
                provide different content based on this header; for example <literal>text/html</literal> can be served for web
                browsers) and at the end we specify that we are expecting <literal>Planet</literal> class via &lit.http.GET;
                request.
            </para>

            <para>
                There may be need for not just producing XML, we might want to consume it as well.

                <example>
                    <title>Method for consuming Planet</title>
                    <programlisting language="java" linenumbering="numbered">@POST
@Consumes(MediaType.APPLICATION_XML)
public void setPlanet(Planet planet) {
    System.out.println("setPlanet " + planet);
}</programlisting>
                </example>

                After valid request is made, service will print out string representation of <literal>Planet</literal>, which can
                look like <literal>Planet{id=2, name='Mars', radius=1.51}</literal>. With JAX-RS client you can do:
                <programlisting language="java" linenumbering="unnumbered">
                    webTarget.path("planet").request().post(Entity.xml(planet));
                </programlisting>
            </para>

            <para>
                If there is a need for some other (non default) XML representation, other JAXB annotations would
                need to be used. This process is usually simplified by generating java source from XML Schema which is
                done by <literal>xjc</literal> which is XML to java compiler and it is part of JAXB.
            </para>
        </section>

        <section>
            <title xml:id="xml.jabx.JAXBElement">POJOs</title>

            <para>
                Sometimes you can't / don't want to add JAXB annotations to source code and you still want to have resources
                consuming and producing XML representation of your classes. In this case, &jaxb.JAXBElement; class should help
                you. Let's redo planet resource but this time we won't have an &jaxb.annotation.XmlRootElement; annotation on
                <literal>Planet</literal> class.
            </para>

            <example>
                <title>Resource class - JAXBElement</title>
                <programlisting language="java" linenumbering="numbered">@Path("planet")
public class Resource {

    @GET
    @Produces(MediaType.APPLICATION_XML)
    public JAXBElement&lt;Planet&gt; getPlanet() {
        Planet planet = new Planet();

        planet.id = 1;
        planet.name = "Earth";
        planet.radius = 1.0;

        return new JAXBElement&lt;Planet&gt;(new QName("planet"), Planet.class, planet);
    }

    @POST
    @Consumes(MediaType.APPLICATION_XML)
    public void setPlanet(JAXBElement&lt;Planet&gt; planet) {
        System.out.println("setPlanet " + planet.getValue());
    }
}</programlisting>
            </example>

            <para>
                As you can see, everything is little more complicated with &lit.jaxb.JAXBElement;. This is because now you need
                to explicitly set element name for <literal>Planet</literal> class XML representation. Client side is even more
                complicated than server side because you can't do <literal>JAXBElement&lt;Planet&gt;</literal> so JAX-RS client
                API provides way how to workaround it by declaring subclass of &lit.jaxrs.core.GenericType;.
            </para>

            <example>
                <title>Client side - JAXBElement</title>
                <programlisting language="java" linenumbering="numbered">// GET
GenericType&lt;JAXBElement&lt;Planet&gt;&gt; planetType = new GenericType&lt;JAXBElement&lt;Planet&gt;&gt;() {};

Planet planet = (Planet) webTarget.path("planet").request(MediaType.APPLICATION_XML_TYPE).get(planetType).getValue();
System.out.println("### " + planet);

// POST
planet = new Planet();

// ...

webTarget.path("planet").post(new JAXBElement&lt;Planet&gt;(new QName("planet"), Planet.class, planet));</programlisting>
            </example>
        </section>

        <section>
            <title xml:id="xml.jaxb.JAXBContext">Using custom JAXBContext</title>

            <para>In some scenarios you can take advantage of using custom &jaxb.JAXBContext;. Creating
                &lit.jaxb.JAXBContext; is an expensive operation and if you already have one created, same instance
                can be used by Jersey. Other possible use-case for this is when you need to set some specific things
                to &lit.jaxb.JAXBContext;, for example to set a different class loader.
            </para>

            <example>
                <title>PlanetJAXBContextProvider</title>
                <programlisting language="java" linenumbering="numbered">@Provider
public class PlanetJAXBContextProvider implements ContextResolver&lt;JAXBContext&gt; {
    private JAXBContext context = null;

    public JAXBContext getContext(Class&lt;?&gt; type) {
        if (type != Planet.class) {
            return null; // we don't support nothing else than Planet
        }

        if (context == null) {
            try {
                context = JAXBContext.newInstance(Planet.class);
            } catch (JAXBException e) {
                // log warning/error; null will be returned which indicates that this
                // provider won't/can't be used.
            }
        }

        return context;
    }
}</programlisting>
            </example>

            <para>
                Sample above shows simple &lit.jaxb.JAXBContext; creation, all you need to do is put
                this &lit.jaxrs.ext.Provider; annotated class somewhere where Jersey can find it. Users sometimes
                have problems with using provider classes on client side, so just to reminder - you have to
                register them in the client config (client does not do anything like package scanning done by server).
            </para>

            <example>
                <title>Using Provider with JAX-RS client</title>
                <programlisting language="java" linenumbering="numbered">
ClientConfig config = new ClientConfig();
config.register(PlanetJAXBContextProvider.class);

Client client = ClientBuilder.newClient(config);
                </programlisting>
            </example>
        </section>

        <section>
            <title>MOXy</title>
            <para>
                If you want to use <link xlink:href='http://www.eclipse.org/eclipselink/moxy.php'>MOXy</link> as your JAXB
                implementation instead of JAXB RI you have two options. You can either use the standard JAXB mechanisms to define
                the <literal>JAXBContextFactory</literal> from which a &lit.jaxb.JAXBContext; instance would be obtained (for more
                on this topic, read JavaDoc on &jaxb.JAXBContext;) or you can add <literal>jersey-media-moxy</literal> module to
                your project and register/configure
                <link xlink:href='&jersey.javadoc.uri.prefix;/moxy/xml/MoxyXmlFeature.html'>MoxyXmlFeature</link> class/instance in
                the &jaxrs.core.Configurable;.
            </para>

            <example>
                <title>Add <literal>jersey-media-moxy</literal> dependency.</title>
                <programlisting language="xml">&lt;dependency&gt;
    &lt;groupId&gt;org.glassfish.jersey.media&lt;/groupId&gt;
    &lt;artifactId&gt;jersey-media-moxy&lt;/artifactId&gt;
    &lt;version&gt;&version;&lt;/version&gt;
&lt;/dependency&gt;</programlisting>
            </example>

            <example>
                <title>Register the <literal>MoxyXmlFeature</literal> class.</title>
                <programlisting language="java" linenumbering="numbered">final ResourceConfig config = new ResourceConfig()
    .packages("org.glassfish.jersey.examples.xmlmoxy")
    .register(MoxyXmlFeature.class);</programlisting>
            </example>

            <example>
                <title>Configure and register an <literal>MoxyXmlFeature</literal> instance.</title>
                <programlisting language="java" linenumbering="numbered">// Configure Properties.
final Map&lt;String, Object&gt; properties = new HashMap&lt;String, Object&gt;();
// ...

// Obtain a ClassLoader you want to use.
final ClassLoader classLoader = Thread.currentThread().getContextClassLoader();

final ResourceConfig config = new ResourceConfig()
    .packages("org.glassfish.jersey.examples.xmlmoxy")
    .register(new MoxyXmlFeature(
        properties,
        classLoader,
        true, // Flag to determine whether eclipselink-oxm.xml file should be used for lookup.
        CustomClassA.class, CustomClassB.class  // Classes to be bound.
    ));</programlisting>
            </example>
        </section>
        <section xml:id="jaxb.configuration">
            <title>Properties for configuring XML providers</title>

            <para>
                Apart from using &lit.jaxrs.ext.ContextResolver; for configuring directly the specific JSON provider classes,
                Jersey supports additional configuration properties prefixed by <literal>JAXB</literal> and <literal>XML</literal>
                that are available in <xref linkend="appendix-properties-message">the appendix.</xref>
            </para>
        </section>
    </section>

    <section xml:id="multipart">
        <title>Multipart</title>
        <titleabbrev id="multipart.short">Multipart</titleabbrev>

        <section>
            <title>Overview</title>

            <para>
                The classes in this module provide an integration of <literal>multipart/*</literal> request and response bodies
                in a JAX-RS runtime environment. The set of registered providers is leveraged, in that the content type for a body
                part of such a message reuses the same &lit.jaxrs.ext.MessageBodyReader;/&lit.jaxrs.ext.MessageBodyWriter;
                implementations as would be used for that content type as a standalone entity.
            </para>

            <para>
                The following list of general MIME MultiPart features is currently supported:

                <itemizedlist>
                    <listitem>
                        <para>
                            The <literal>MIME-Version: 1.0</literal> HTTP header is included on generated responses.
                            It is accepted, but not required, on processed requests.
                        </para>
                    </listitem>
                    <listitem>
                        <para>
                            A &jaxrs.ext.MessageBodyReader; implementation for consuming MIME MultiPart entities.
                        </para>
                    </listitem>
                    <listitem>
                        <para>
                            A &lit.jaxrs.ext.MessageBodyWriter; implementation for producing MIME MultiPart entities.
                            The appropriate &lit.jaxrs.ext.Provider; is used to serialize each body part, based on its media type.
                        </para>
                    </listitem>
                    <listitem>
                        <para>
                            Optional creation of an appropriate <literal>boundary</literal> parameter on a generated
                            <literal>Content-Type</literal> header, if not already present.
                        </para>
                    </listitem>
                </itemizedlist>
            </para>

            <para>
                For more information refer to &jersey.media.multipart;.
            </para>

            <section>
                <title>Dependency</title>

                <para>
                    To use multipart features you need to add &lit.jersey-media-multipart; module to your &lit.pom.xml; file:

                    <programlisting language="xml">&lt;dependency&gt;
    &lt;groupId&gt;org.glassfish.jersey.media&lt;/groupId&gt;
    &lt;artifactId&gt;jersey-media-multipart&lt;/artifactId&gt;
    &lt;version&gt;&version;&lt;/version&gt;
&lt;/dependency&gt;</programlisting>

                    If you're not using Maven make sure to have all needed dependencies (see &jersey.media.multipart.deps.link;) on the
                    class-path.
                </para>
            </section>

            <section>
                <title>Registration</title>

                <para>
                    Before you can use capabilities of the &lit.jersey-media-multipart; module in your client/server code, you
                    need to register &jersey.media.multipart.MultiPartFeature;.

                    <example>
                        <title>Building client with MultiPart feature enabled.</title>

                        <programlisting language="java">final Client client = ClientBuilder.newBuilder()
    .register(MultiPartFeature.class)
    .build();</programlisting>
                    </example>

                    <example>
                        <title>Creating JAX-RS application with MultiPart feature enabled.</title>

                        <programlisting language="java">// Create JAX-RS application.
final Application application = new ResourceConfig()
    .packages("org.glassfish.jersey.examples.multipart")
    .register(MultiPartFeature.class)</programlisting>
                    </example>
                </para>
            </section>

            <section>
                <title>Examples</title>

                <para>Jersey provides a
                    <link xlink:href='&jersey.github.examples.uri;/multipart-webapp'>Multipart Web Application Example</link>
                    on how to use multipart features.</para>
            </section>
        </section>

        <section>
            <title>Client</title>

            <para>
                &jersey.media.multipart.MultiPart; class (or it's subclasses) can be used as an entry point to use
                &lit.jersey-media-multipart; module on the client side. This class represents a
                <link xlink:href='&wikipedia.uri;MIME#Multipart_messages'>MIME multipart message</link> and is able
                to hold an arbitrary number of &jersey.media.multipart.BodyPart;s. Default media type is
                <link xlink:href='&wikipedia.uri;MIME#Mixed'>multipart/mixed</link>
                for &lit.jersey.media.multipart.MultiPart; entity and <literal>text/plain</literal> for
                &lit.jersey.media.multipart.BodyPart;.

                <example>
                    <title>&lit.jersey.media.multipart.MultiPart; entity</title>

                    <programlisting language="java">final MultiPart multiPartEntity = new MultiPart()
        .bodyPart(new BodyPart().entity("hello"))
        .bodyPart(new BodyPart(new JaxbBean("xml"), MediaType.APPLICATION_XML_TYPE))
        .bodyPart(new BodyPart(new JaxbBean("json"), MediaType.APPLICATION_JSON_TYPE));

final WebTarget target = // Create WebTarget.
final Response response = target
        .request()
        .post(Entity.entity(multiPartEntity, multiPartEntity.getMediaType()));</programlisting>
                </example>

                If you send a <literal>multiPartEntity</literal> to the server the entity with <literal>Content-Type</literal>
                header in HTTP message would look like (don't forget to register a JSON provider):

                <example>
                    <title>&lit.jersey.media.multipart.MultiPart; entity in HTTP message.</title>

                    <screen language="text" linenumbering="unnumbered"><emphasis>Content-Type: multipart/mixed; boundary=Boundary_1_829077776_1369128119878</emphasis>

--Boundary_1_829077776_1369128119878
Content-Type: text/plain

hello
--Boundary_1_829077776_1369128119878
Content-Type: application/xml

&lt;?xml version="1.0" encoding="UTF-8" standalone="yes"?&gt;&lt;jaxbBean&gt;&lt;value&gt;xml&lt;/value&gt;&lt;/jaxbBean&gt;
--Boundary_1_829077776_1369128119878
Content-Type: application/json

{"value":"json"}
--Boundary_1_829077776_1369128119878--</screen>
                </example>
            </para>
            <para>
                When working with forms (e.g. media type <literal>multipart/form-data</literal>) and various fields in them,
                there is a more convenient class to be used - &jersey.media.multipart.FormDataMultiPart;. It automatically sets
                the media type for the &lit.jersey.media.multipart.FormDataMultiPart; entity to
                <literal>multipart/form-data</literal> and <literal>Content-Disposition</literal> header to
                &lit.jersey.media.multipart.FormDataBodyPart; body parts.

                <example>
                    <title>&lit.jersey.media.multipart.FormDataMultiPart; entity</title>
                    <programlisting language="java">final FormDataMultiPart multipart = new FormDataMultiPart()
    .field("hello", "hello")
    .field("xml", new JaxbBean("xml"))
    .field("json", new JaxbBean("json"), MediaType.APPLICATION_JSON_TYPE);

final WebTarget target = // Create WebTarget.
final Response response = target.request().post(Entity.entity(multipart, multipart.getMediaType()));</programlisting>
                </example>

                To illustrate the difference when using &lit.jersey.media.multipart.FormDataMultiPart; instead of
                &lit.jersey.media.multipart.FormDataBodyPart; you can take a look at the
                &lit.jersey.media.multipart.FormDataMultiPart; entity from HTML message:

                <example>
                    <title>&lit.jersey.media.multipart.FormDataMultiPart; entity in HTTP message.</title>

                    <screen language="text" linenumbering="unnumbered"><emphasis>Content-Type: multipart/form-data; boundary=Boundary_1_511262261_1369143433608</emphasis>

--Boundary_1_511262261_1369143433608
Content-Type: text/plain
Content-Disposition: form-data; name="hello"

hello
--Boundary_1_511262261_1369143433608
Content-Type: application/xml
Content-Disposition: form-data; name="xml"

&lt;?xml version="1.0" encoding="UTF-8" standalone="yes"?&gt;&lt;jaxbBean&gt;&lt;value&gt;xml&lt;/value&gt;&lt;/jaxbBean&gt;
--Boundary_1_511262261_1369143433608
Content-Type: application/json
Content-Disposition: form-data; name="json"

{"value":"json"}
--Boundary_1_511262261_1369143433608--</screen>
                </example>
            </para>
            <para>
                A common use-case for many users is sending files from client to server. For this purpose you can use classes from
                <literal>org.glassfish.jersey.jersey.media.multipart</literal> package, such as
                &jersey.media.multipart.FileDataBodyPart; or &jersey.media.multipart.StreamDataBodyPart;.

                <example>
                    <title>Multipart - sending files.</title>

                    <programlisting language="java">// MediaType of the body part will be derived from the file.
final FileDataBodyPart filePart = new FileDataBodyPart("my_pom", new File("pom.xml"));

final FormDataMultiPart multipart = new FormDataMultiPart()
    .field("foo", "bar")
    .bodyPart(filePart);

final WebTarget target = // Create WebTarget.
final Response response = target.request()
    .post(Entity.entity(multipart, multipart.getMediaType()));</programlisting>
                </example>
            </para>
            <warning>
                <para>
                    Do not use &lit.jersey.apache.ApacheConnectorProvider; nor &lit.jersey.grizzly.GrizzlyConnectorProvider;
                    neither &lit.jersey.jetty.JettyConnectorProvider; connector implementations with Jersey Multipart
                    features. See <xref linkend="connectors.warning"/> warning for more details.
                </para>
            </warning>
        </section>

        <section>
            <title>Server</title>

            <para>
                Returning a multipart response from server to client is not much different from the parts described in the client
                section above. To obtain a multipart entity, sent by a client, in the application you can use two approaches:

                <itemizedlist>
                    <listitem>
                        <para>Injecting the whole &jersey.media.multipart.MultiPart; entity.</para>
                    </listitem>
                    <listitem>
                        <para>
                            Injecting particular parts of a <literal>form-data</literal> multipart request via
                            &jersey.media.multipart.FormDataParam; annotation.
                        </para>
                    </listitem>
                </itemizedlist>
            </para>

            <section>
                <title>Injecting and returning the &lit.jersey.media.multipart.MultiPart; entity</title>

                <para>
                    Working with &lit.jersey.media.multipart.MultiPart; types is no different from injecting/returning other
                    entity types.
                    Jersey provides &lit.jaxrs.ext.MessageBodyReader; for reading the request entity and injecting this entity
                    into a method parameter of a resource method and &lit.jaxrs.ext.MessageBodyWriter; for writing output entities.
                    You can expect that either &lit.jersey.media.multipart.MultiPart; or
                    &lit.jersey.media.multipart.FormDataMultiPart; (<literal>multipart/form-data</literal> media type) object
                    to be injected into a resource method.
                </para>

                <example>
                    <title>Resource method using &lit.jersey.media.multipart.MultiPart; as input parameter / return value.</title>

                    <programlisting language="java">@POST
@Produces("multipart/mixed")
public MultiPart post(final FormDataMultiPart multiPart) {
    return multiPart;
}</programlisting>
                </example>
            </section>

            <section>
                <title>Injecting with &lit.jersey.media.multipart.FormDataParam;</title>

                <para>
                    If you just need to bind the named body part(s) of a <literal>multipart/form-data</literal> request
                    entity body to a resource method parameter you can use &jersey.media.multipart.FormDataParam; annotation.
                </para>
                <para>
                    This annotation in conjunction with the media type <literal>multipart/form-data</literal> should be used for
                    submitting and consuming forms that contain files, non-ASCII data, and binary data.
                </para>
                <para>
                    The type of the annotated parameter can be one of the following (for more detailed description see
                    javadoc to &jersey.media.multipart.FormDataParam;):

                    <itemizedlist>
                        <listitem>
                            <para>
                                &lit.jersey.media.multipart.FormDataBodyPart; - The value of the parameter will be the first
                                named body part or &lit.null; if such a named body part is not present.
                            </para>
                        </listitem>
                        <listitem>
                            <para>
                                A <literal>List</literal> or <literal>Collection</literal> of
                                &lit.jersey.media.multipart.FormDataBodyPart;.
                                The value of the parameter will be one or more named body parts with the same name or
                                &lit.null; if such a named body part is not present.
                            </para>
                        </listitem>
                        <listitem>
                            <para>
                                &lit.jersey.media.multipart.FormDataContentDisposition; - The value of the parameter will be the
                                content disposition of the first named body part part or &lit.null; if such a named body part
                                is not present.
                            </para>
                        </listitem>
                        <listitem>
                            <para>
                                A <literal>List</literal> or <literal>Collection</literal> of
                                &lit.jersey.media.multipart.FormDataContentDisposition;.
                                The value of the parameter will be one or more content dispositions of the named body parts with the
                                same name or &lit.null; if such a named body part is not present.
                            </para>
                        </listitem>
                        <listitem>
                            <para>
                                A type for which a message body reader is available given the media type of the first named body
                                part. The value of the parameter will be the result of reading using the message body reader given
                                the type <literal>T</literal>, the media type of the named part, and the bytes of the named body
                                part as input.
                            </para>
                            <para>
                                If there is no named part present and there is a default value present as declared by
                                &jaxrs.DefaultValue; then the media type will be set to <literal>text/plain</literal>.
                                The value of the parameter will be the result of reading using the message body reader given the
                                type <literal>T</literal>, the media type <literal>text/plain</literal>, and the UTF-8 encoded
                                bytes of the default value as input.
                            </para>
                            <para>
                                If there is no message body reader available and the type <literal>T</literal> conforms
                                to a type specified by &jaxrs.FormParam; then processing is performed as specified by
                                &lit.jaxrs.FormParam;, where the values of the form parameter are <literal>String</literal>
                                instances produced by reading the bytes of the named body parts utilizing a message body reader
                                for the <literal>String</literal> type and the media type <literal>text/plain</literal>.
                            </para>
                            <para>
                                If there is no named part present then processing is performed as specified by
                                &lit.jaxrs.FormParam;.
                            </para>
                        </listitem>
                    </itemizedlist>
                </para>

                <example>
                    <title>Use of &lit.jersey.media.multipart.FormDataParam; annotation</title>

                    <programlisting language="java">@POST
@Consumes(MediaType.MULTIPART_FORM_DATA)
public String postForm(
    @DefaultValue("true") @FormDataParam("enabled") boolean enabled,
    @FormDataParam("data") FileData bean,
    @FormDataParam("file") InputStream file,
    @FormDataParam("file") FormDataContentDisposition fileDisposition) {

    // ...
}</programlisting>
                </example>

                <para>
                    In the example above the server consumes a <literal>multipart/form-data</literal> request entity body that
                    contains one optional named body part <literal>enabled</literal> and two required named body parts
                    <literal>data</literal> and <literal>file</literal>.
                </para>
                <para>
                    The optional part <literal>enabled</literal> is processed
                    as a <literal>boolean</literal> value, if the part is absent then the value will be <literal>true</literal>.
                </para>
                <para>
                    The part <literal>data</literal> is processed as a JAXB bean and contains some meta-data about the following
                    part.
                </para>
                <para>
                    The part <literal>file</literal> is a file that is uploaded, this is processed as an
                    <literal>InputStream</literal>. Additional information about the file from the
                    <literal>Content-Disposition</literal> header can be accessed by the parameter
                    <literal>fileDisposition</literal>.
                </para>

                <tip>
                    <para>&lit.jersey.media.multipart.FormDataParam; annotation can be also used on fields.</para>
                </tip>
            </section>
        </section>
    </section>
</chapter>