Test Quarkus Jackson ObjectMapper with JacksonDataFormat + Docs

docs/modules/ROOT/pages/reference/extensions/jackson.adoc

@@ -38,3 +38,80 @@ Or add the coordinates to your existing project:
 ----
 
 Check the xref:user-guide/index.adoc[User guide] for more information about writing Camel Quarkus applications.
+
+== Usage
+
+=== Configuring the Jackson `ObjectMapper`
+
+There are a few ways of configuring the `ObjectMapper` that the `JacksonDataFormat` uses. These are outlined below.
+
+==== `ObjectMapper` created internally by `JacksonDataFormat`
+
+By default, `JacksonDataFormat` will create its own `ObjectMapper` and use the various configuration options on the `DataFormat`
+to configure additional Jackson modules, pretty printing and other features.
+
+==== Custom `ObjectMapper` for `JacksonDataFormat`
+
+You can pass a custom `ObjectMapper` instance to `JacksonDataFormat` as follows.
+
+[source,java]
+----
+ObjectMapper mapper = new ObjectMapper();
+JacksonDataFormat dataFormat = new JacksonDataFormat();
+dataFormat.setObjectMapper(mapper);
+----
+
+==== Using the Quarkus Jackson `ObjectMapper` with `JacksonDataFormat`
+
+The Quarkus Jackson extension exposes an `ObjectMapper` CDI bean which can be discovered by the `JacksonDataFormat`.
+
+[source,java]
+----
+ObjectMapper mapper = new ObjectMapper();
+JacksonDataFormat dataFormat = new JacksonDataFormat();
+// Make JacksonDataFormat discover the Quarkus Jackson `ObjectMapper` from the Camel registry
+dataFormat.setAutoDiscoverObjectMapper(true);
+----
+
+If you are using the JSON binding mode in the Camel REST DSL and want to use the Quarkus Jackson `ObjectMapper`, it can be achieved as follows.
+
+[source,java]
+----
+@ApplicationScoped
+public class Routes extends RouteBuilder() {
+    public void configure() {
+        restConfiguration().dataFormatProperty("autoDiscoverObjectMapper", "true");
+        // REST definition follows...
+    }
+}
+----
+
+You can perform customizations on the Quarkus `ObjectMapper` with a `ObjectMapperCustomizer`.
+
+[source,java]
+----
+@Singleton
+public class RegisterCustomModuleCustomizer implements ObjectMapperCustomizer {
+    public void customize(ObjectMapper mapper) {
+        mapper.registerModule(new CustomModule());
+    }
+}
+----
+
+It's also possible to `@Inject` the Quarkus `ObjectMapper` and pass it to the `JacksonDataFormat`.
+
+[source,java]
+----
+@ApplicationScoped
+public class Routes extends RouteBuilder() {
+    @Inject
+    ObjectMapper mapper;
+
+    public void configure() {
+        JacksonDataFormat dataFormat = new JacksonDataFormat();
+        dataFormat.setObjectMapper(mapper);
+        // Routes definition follows...
+    }
+}
+----
+

extensions/jackson/runtime/src/main/doc/usage.adoc

@@ -0,0 +1,73 @@
+=== Configuring the Jackson `ObjectMapper`
+
+There are a few ways of configuring the `ObjectMapper` that the `JacksonDataFormat` uses. These are outlined below.
+
+==== `ObjectMapper` created internally by `JacksonDataFormat`
+
+By default, `JacksonDataFormat` will create its own `ObjectMapper` and use the various configuration options on the `DataFormat`
+to configure additional Jackson modules, pretty printing and other features.
+
+==== Custom `ObjectMapper` for `JacksonDataFormat`
+
+You can pass a custom `ObjectMapper` instance to `JacksonDataFormat` as follows.
+
+[source,java]
+----
+ObjectMapper mapper = new ObjectMapper();
+JacksonDataFormat dataFormat = new JacksonDataFormat();
+dataFormat.setObjectMapper(mapper);
+----
+
+==== Using the Quarkus Jackson `ObjectMapper` with `JacksonDataFormat`
+
+The Quarkus Jackson extension exposes an `ObjectMapper` CDI bean which can be discovered by the `JacksonDataFormat`.
+
+[source,java]
+----
+ObjectMapper mapper = new ObjectMapper();
+JacksonDataFormat dataFormat = new JacksonDataFormat();
+// Make JacksonDataFormat discover the Quarkus Jackson `ObjectMapper` from the Camel registry
+dataFormat.setAutoDiscoverObjectMapper(true);
+----
+
+If you are using the JSON binding mode in the Camel REST DSL and want to use the Quarkus Jackson `ObjectMapper`, it can be achieved as follows.
+
+[source,java]
+----
+@ApplicationScoped
+public class Routes extends RouteBuilder() {
+    public void configure() {
+        restConfiguration().dataFormatProperty("autoDiscoverObjectMapper", "true");
+        // REST definition follows...
+    }
+}
+----
+
+You can perform customizations on the Quarkus `ObjectMapper` with a `ObjectMapperCustomizer`.
+
+[source,java]
+----
+@Singleton
+public class RegisterCustomModuleCustomizer implements ObjectMapperCustomizer {
+    public void customize(ObjectMapper mapper) {
+        mapper.registerModule(new CustomModule());
+    }
+}
+----
+
+It's also possible to `@Inject` the Quarkus `ObjectMapper` and pass it to the `JacksonDataFormat`.
+
+[source,java]
+----
+@ApplicationScoped
+public class Routes extends RouteBuilder() {
+    @Inject
+    ObjectMapper mapper;
+
+    public void configure() {
+        JacksonDataFormat dataFormat = new JacksonDataFormat();
+        dataFormat.setObjectMapper(mapper);
+        // Routes definition follows...
+    }
+}
+----

integration-tests/dataformats-json/src/main/java/org/apache/camel/quarkus/component/dataformats/jackson/json/JacksonJsonResource.java

@@ -43,6 +43,7 @@
 import org.apache.camel.component.mock.MockEndpoint;
 import org.apache.camel.quarkus.component.dataformats.json.model.DummyObject;
 import org.apache.camel.quarkus.component.dataformats.json.model.Order;
+import org.apache.camel.quarkus.component.dataformats.json.model.Person;
 import org.apache.camel.quarkus.component.dataformats.json.model.Pojo;
 import org.apache.camel.quarkus.component.dataformats.json.model.TestJAXBPojo;
 import org.apache.camel.quarkus.component.dataformats.json.model.TestOtherPojo;
@@ -249,17 +250,16 @@ public void jacksonMarshalGeneral() throws Exception {
     @Path("jackson/object-mapper")
     @GET
     public void jacksonObjectMapper() throws Exception {
-        Map<String, Object> in = new HashMap<>();
-        in.put("name", "Camel");
+        Person person = new Person("John", "Doe", 44);
 
         MockEndpoint mock = context.getEndpoint("mock:jackson-objectmapper-reverse", MockEndpoint.class);
         mock.expectedMessageCount(1);
-        mock.message(0).body().isInstanceOf(Map.class);
-        mock.message(0).body().isEqualTo(in);
+        mock.message(0).body().isInstanceOf(Person.class);
+        mock.message(0).body().isEqualTo(person);
 
-        Object marshalled = producerTemplate.requestBody("direct:jackson-objectmapper-in", in);
+        Object marshalled = producerTemplate.requestBody("direct:jackson-objectmapper-in", person);
         String marshalledAsString = context.getTypeConverter().convertTo(String.class, marshalled);
-        assertEquals("{\"name\":\"Camel\"}", marshalledAsString);
+        assertEquals("{\"first_name\":\"John\",\"last_name\":\"Doe\",\"age\":44}", marshalledAsString);
 
         producerTemplate.sendBody("direct:jackson-objectmapper-back", marshalled);
 
@@ -495,7 +495,7 @@ public void jacksonConversionPojo(String body) throws Exception {
             order.setPartName("Camel");
 
             String json = (String) producerTemplate.requestBody("direct:jackson-conversion-pojo-test", order);
-            assertEquals("{\"id\":0,\"partName\":\"Camel\",\"amount\":1,\"customer_name\":\"Acme\"}", json);
+            assertEquals("{\"id\":0,\"part_name\":\"Camel\",\"amount\":1,\"customer_name\":\"Acme\"}", json);
         }
 
     }

integration-tests/dataformats-json/src/main/java/org/apache/camel/quarkus/component/dataformats/jackson/json/JacksonJsonRoute.java

@@ -29,6 +29,7 @@
 import org.apache.camel.model.dataformat.JsonLibrary;
 import org.apache.camel.quarkus.component.dataformats.json.model.DummyObject;
 import org.apache.camel.quarkus.component.dataformats.json.model.MyModule;
+import org.apache.camel.quarkus.component.dataformats.json.model.Person;
 import org.apache.camel.quarkus.component.dataformats.json.model.Pojo;
 import org.apache.camel.quarkus.component.dataformats.json.model.TestJAXBPojo;
 import org.apache.camel.quarkus.component.dataformats.json.model.TestPojo;
@@ -78,8 +79,7 @@ public void configure() throws Exception {
         from("direct:jackson-marshal-inPojo").marshal(formatPojo);
         from("direct:jackson-marshal-backPojo").unmarshal(formatPojo).to("mock:jackson-marshal-reversePojo");
 
-        this.getContext().getRegistry().bind("myMapper", new ObjectMapper());
-        JacksonDataFormat objectMapperFormat = new JacksonDataFormat();
+        JacksonDataFormat objectMapperFormat = new JacksonDataFormat(Person.class);
         objectMapperFormat.setAutoDiscoverObjectMapper(true);
         from("direct:jackson-objectmapper-in").marshal(objectMapperFormat);
         from("direct:jackson-objectmapper-back").unmarshal(objectMapperFormat).to("mock:jackson-objectmapper-reverse");

integration-tests/dataformats-json/src/main/java/org/apache/camel/quarkus/component/dataformats/jackson/json/NamingStrategyCustomizer.java

@@ -0,0 +1,31 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.camel.quarkus.component.dataformats.jackson.json;
+
+import javax.inject.Singleton;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.PropertyNamingStrategies;
+import io.quarkus.jackson.ObjectMapperCustomizer;
+
+@Singleton
+public class NamingStrategyCustomizer implements ObjectMapperCustomizer {
+    public void customize(ObjectMapper mapper) {
+        // Use snake case property names, so that we can verify the Quarkus ObjectMapper really is being used
+        mapper.setPropertyNamingStrategy(PropertyNamingStrategies.SNAKE_CASE);
+    }
+}

integration-tests/dataformats-json/src/main/java/org/apache/camel/quarkus/component/dataformats/json/model/Person.java

@@ -0,0 +1,81 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.camel.quarkus.component.dataformats.json.model;
+
+import java.util.Objects;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+import io.quarkus.runtime.annotations.RegisterForReflection;
+
+@RegisterForReflection(fields = false)
+public class Person {
+
+    @JsonProperty
+    private String firstName;
+    @JsonProperty
+    private String lastName;
+    @JsonProperty
+    private int age;
+
+    public Person() {
+    }
+
+    public Person(String firstName, String lastName, int age) {
+        this.firstName = firstName;
+        this.lastName = lastName;
+        this.age = age;
+    }
+
+    public String getFirstName() {
+        return firstName;
+    }
+
+    public void setFirstName(String firstName) {
+        this.firstName = firstName;
+    }
+
+    public String getLastName() {
+        return lastName;
+    }
+
+    public void setLastName(String lastName) {
+        this.lastName = lastName;
+    }
+
+    public int getAge() {
+        return age;
+    }
+
+    public void setAge(int age) {
+        this.age = age;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o)
+            return true;
+        if (o == null || getClass() != o.getClass())
+            return false;
+        Person person = (Person) o;
+        return age == person.age && Objects.equals(firstName, person.firstName) && Objects.equals(lastName, person.lastName);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(firstName, lastName, age);
+    }
+}