Deserializing when using custom wrapper element

[mortenoh]

I'm having some issues deserializing a class that uses a @JacksonXmlElementWrapper.

This how my class looks:

@JacksonXmlRootElement( localName = "person", namespace ="http://example.org/person" )
public class Person
{
   @JacksonXmlProperty( isAttribute = true )
   private String id;

   private String name;

   private Integer age;

   @JacksonXmlElementWrapper(localName = "notes")
   @JacksonXmlProperty( localName = "note" )
   private List<String> notes = new ArrayList<String>();

  // getters, setters, etc
}

And this gets serialized fine with:

Person p = new Person( "Name", 30 );
p.getNotes().add( "This is note #1" );
p.getNotes().add( "This is note #2" );

ObjectMapper xmlMapper = new XmlMapper();
String xml = xmlMapper.writeValueAsString( p );

This gives me something like:

<zdef-1759520061:person xmlns=""
xmlns:zdef-1759520061="http://example.org/person"
id="af47ac8e-ee8c-4e43-a87c-dbff93f28d87">
 <name>Name</name>
 <age>30</age>
 <notes>
   <note>This is note #1</note>
   <note>This is note #2</note>
 </notes>
</zdef-1759520061:person>

But, when I now try and deserialize this using:

Person p = xmlMapper.readValue( xml, Person.class );

I get:

Exception in thread "main"
com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException:
Unrecognized field "notes" (Class Person), not marked as ignorable
 at [Source: java.io.StringReader@5c1fe88d; line: 1, column: 169]
(through reference chain: Person["notes"])
       at com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException.from(UnrecognizedPropertyException.java:51)
       at com.fasterxml.jackson.databind.DeserializationContext.reportUnknownProperty(DeserializationContext.java:526)
       at com.fasterxml.jackson.databind.deser.std.StdDeserializer.handleUnknownProperty(StdDeserializer.java:651)
       at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.handleUnknownProperty(BeanDeserializerBase.java:771)
       at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserializeFromObject(BeanDeserializer.java:291)
       at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:99)
       at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:2532)
       at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:1774)

[cowtowncoder]

Adding unit test: can reproduce the problem as described... will try to see what gives the problem.

[cowtowncoder]

Looks like there is discrepancy between expected regular name, wrapper name (for test, changing local name to be 'notes' makes test pass for example).

[cowtowncoder]

Managed to fix by checking and using wrapper name for deserialization, instead of property name.

[cowtowncoder]

Strange. Things work ok when annotations are added on setters, but not when added on getters...

[cowtowncoder]

Ok: needed to add quite a bit more code, workarounds than anticipated, but things now work.
New code should be more robust as well. Please let me know if I still managed to miss something...

[fredcooke]

I appear to still be getting this, or something similar, in 2.1.3. I've got annotations setup to correctly create this:

<Root BuildVersion="1.1.1" Description="horribleformatthati'mstuckwith" DataInterchangeType="dit" Locale="local pub">
    <Batch name="botched">
        <Documents>
            <Document DocID="hg is better" DocType="rocksml" MimeType="daddytype">
                <Tags>
                    <Tag id="hello" TagName="icknd" TagDataType="pasta">of no value at all</Tag>
                    <Tag id="hello2" TagName="icknd2" TagDataType="pasta2">of no value at all2</Tag>
                </Tags>
            </Document>
            <Document DocID="git is better" DocType="sucksml" MimeType="mummytype">
                <Tags>
                    <Tag id="hell3o" TagName="ick3nd" TagDataType="p3asta">of no v3alue at all</Tag>
                    <Tag id="hello42" TagName="icknd42" TagDataType="pas4ta2">of no value at al4l2</Tag>
                </Tags>
            </Document>
        </Documents>
    </Batch>
</Root>

However it can not read it back in, giving the following slightly sanitised error:

Caused by: com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException: Unrecognized field "Documents" (class com.example.bcn.tara.xml.perceptive.Batch), not marked as ignorable (2 known properties: , "name", "Document"])
 at [Source: java.io.FileInputStream@243f01d4; line: 1, column: 221] (through reference chain: com.example.bcn.tara.xml.Perceptive["Batch"]->com.example.bcn.tara.xml.perceptive.Batch["Documents"])
    at com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException.from(UnrecognizedPropertyException.java:79)
    at com.fasterxml.jackson.databind.DeserializationContext.reportUnknownProperty(DeserializationContext.java:579)
    at com.fasterxml.jackson.databind.deser.std.StdDeserializer.handleUnknownProperty(StdDeserializer.java:672)
    at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.handleUnknownProperty(BeanDeserializerBase.java:906)
    at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserializeFromObject(BeanDeserializer.java:328)
    at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:121)
    at com.fasterxml.jackson.databind.deser.SettableBeanProperty.deserialize(SettableBeanProperty.java:375)
    at com.fasterxml.jackson.databind.deser.impl.MethodProperty.deserializeAndSet(MethodProperty.java:98)
    at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserializeFromObject(BeanDeserializer.java:308)
    at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:121)
    at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:2797)
    at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:1989)
    at com.example.bcn.tara.XMLMain.main(XMLMain.java:85)
    ... 6 more

The relevant lines from the Batch object:

    @JacksonXmlProperty(isAttribute=true)
    private String name;
    @JacksonXmlElementWrapper(localName="Documents")
    @JacksonXmlProperty(localName="Document")
    private List<Document> documents;

Let me know if I can help in any way. I'm happy to try snapshots if you deploy them to sonatype's OSS repo.

[fredcooke]

FYI, I could, of course, serialise and deserialise in both JSON and YAML using 2.1.3. In the end having heard nothing back from you guys, I tried simple 2.6.9, and found it to not be simple at all. Then I tried XStream and it works superbly. I'm still interested in seeing this resolved, though, as I would REALLY like to use Jackson as my catch-all serialiser/deserialiser across all of XML, JSON, YAML in a single application.

[cowtowncoder]

Sorry for slow response here. There are issues with List (de)serialization, and I hope they all come from a single root cause, to be fixed for Jackson 2.2.

[cowtowncoder]

After fixing other issues (#47, #55), I think this may well have been fixed: if anyone thinks there are leftovers from this one, please file a new issue.