Unmarshalling array of complex JSON objects with MOXy JAXB 2.5.1 - json

Question

I'm trying to use MOXy JAXB to unmarshal some JSON/XML in an Apache CFX project. The following request gives me trouble:
{"CC.ConsumerPersistAppDataRequest" : {
"SessionId" : "42",
"AppData" : [
{"AppDatum" : {
"TimeStamp" : 1384548486,
"Value" : "Some kind of String would go here"}},
{"AppDatum" : {
"TimeStamp" : 1384548578,
"Value" : "I hope I am understanding this format correctly!"}},
{"AppDatum" : {
"TimeStamp" : 1384549696,
"Value" : "One more time for the road..."}}],
"MetaDataTags" : ["dumb", "dummy", "data"]}
}
Here, AppData is unmarshalled as a List<AppDatum>, however the list only contains the last element. Notably, the "MetaDataTags" element is correctly unmarshalled as a List<String> of size 3.
Surprisingly, the following request can be submitted with the same result, despite the fact the "AppData" should expect a List<AppDatum> (I can't help but feel this is related):
{"CC.ConsumerPersistAppDataRequest" : {
"SessionId" : "42",
"AppData" : {
"AppDatum" : {
"TimeStamp" : 1384548486,
"Value" : "Some kind of String would go here"
}
}
}}
This XML equivalent (or what I see to be the XML equivalent) is parsed as expected:
<?xml version="1.0" encoding="UTF-8"?>
<cc:ConsumerPersistAppDataRequest xmlns:cc="http://org/alg/ari/pnd/introspect/webservices/consumercomms">
<SessionId>42</SessionId>
<AppData>
<AppDatum>
<TimeStamp>1384548486</TimeStamp>
<Value>Some kind of String would go here</Value>
</AppDatum>
<AppDatum>
<TimeStamp>1384548578</TimeStamp>
<Value>I hope I am understanding this format correctly!</Value>
</AppDatum>
<AppDatum>
<TimeStamp>1384549696</TimeStamp>
<Value>One more time for the road...</Value>
</AppDatum>
</AppData>
<MetaDataTags>dumb dummy data</MetaDataTags>
</cc:ConsumerPersistAppDataRequest>
The JAXB class in question (generated by XJC, comments elided):
package org.alg.ari.pnd.introspect.webservices.consumercomms;
import java.util.ArrayList;
import java.util.List;
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlList;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlType;
#XmlAccessorType(XmlAccessType.FIELD)
#XmlType(name = "", propOrder = {
"sessionId",
"appData",
"metaDataTags"
})
#XmlRootElement(name = "ConsumerPersistAppDataRequest")
public class ConsumerPersistAppDataRequest {
#XmlElement(name = "SessionId", required = true)
protected String sessionId;
#XmlElement(name = "AppData", required = true)
protected ConsumerPersistAppDataRequest.AppData appData;
#XmlList
#XmlElement(name = "MetaDataTags", required = true)
protected List<String> metaDataTags;
public String getSessionId() {
return sessionId;
}
public void setSessionId(String value) {
this.sessionId = value;
}
public ConsumerPersistAppDataRequest.AppData getAppData() {
return appData;
}
public void setAppData(ConsumerPersistAppDataRequest.AppData value) {
this.appData = value;
}
public List<String> getMetaDataTags() {
if (metaDataTags == null) {
metaDataTags = new ArrayList<String>();
}
return this.metaDataTags;
}
#XmlAccessorType(XmlAccessType.FIELD)
#XmlType(name = "", propOrder = {
"appDatum"
})
public static class AppData {
#XmlElement(name = "AppDatum", required = true)
protected List<ConsumerPersistAppDataRequest.AppData.AppDatum> appDatum;
public List<ConsumerPersistAppDataRequest.AppData.AppDatum> getAppDatum() {
if (appDatum == null) {
appDatum = new ArrayList<ConsumerPersistAppDataRequest.AppData.AppDatum>();
}
return this.appDatum;
}
#XmlAccessorType(XmlAccessType.FIELD)
#XmlType(name = "", propOrder = {
"timeStamp",
"value"
})
public static class AppDatum {
#XmlElement(name = "TimeStamp")
protected long timeStamp;
#XmlElement(name = "Value", required = true)
protected String value;
public long getTimeStamp() {
return timeStamp;
}
public void setTimeStamp(long value) {
this.timeStamp = value;
}
public String getValue() {
return value;
}
public void setValue(String value) {
this.value = value;
}
}
}
}
and my MoxyJsonProvider bean
<bean id="moxy-json-provider"
class="org.eclipse.persistence.jaxb.rs.MOXyJsonProvider">
<property name="attributePrefix" value="#" />
<property name="formattedOutput" value="true" /> <!-- set to false for production! -->
<property name="includeRoot" value="true" />
<property name="marshalEmptyCollections" value="false" />
<property name="valueWrapper" value="$" />
<property name="namespacePrefixMapper" ref="json-ns-mapper" />
</bean>
Any idea what could be causing this issue? Is this a bug in the 2.5.1 Release of MOXy? Or is there a "switch" somewhere that I need to set?

Answer 1

Based on your mapping, the folloiwng would be the expected JSON document:
{
"CC.ConsumerPersistAppDataRequest" : {
"SessionId" : "42",
"AppData" : {
"AppDatum" : [ {
"TimeStamp" : 1384548486,
"Value" : "Some kind of String would go here"
}, {
"TimeStamp" : 1384548578,
"Value" : "I hope I am understanding this format correctly!"
}, {
"TimeStamp" : 1384549696,
"Value" : "One more time for the road..."
} ]
},
"MetaDataTags" : "dumb dummy data"
}
}
The following is the standalone example I wrote based on yours to read in the XML and output the corresponding JSON:
import java.io.File;
import java.util.*;
import javax.xml.bind.*;
import org.eclipse.persistence.jaxb.MarshallerProperties;
public class Demo {
public static void main(String[] args) throws Exception {
JAXBContext jc = JAXBContext.newInstance(ConsumerPersistAppDataRequest.class);
Unmarshaller unmarshaller = jc.createUnmarshaller();
File xml = new File("src/forum20056524/input.xml");
ConsumerPersistAppDataRequest result = (ConsumerPersistAppDataRequest) unmarshaller.unmarshal(xml);
Marshaller marshaller = jc.createMarshaller();
marshaller.setProperty(MarshallerProperties.MEDIA_TYPE, "application/json");
marshaller.setProperty(MarshallerProperties.JSON_ATTRIBUTE_PREFIX, "#");
marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
marshaller.setProperty(MarshallerProperties.JSON_INCLUDE_ROOT, true);
marshaller.setProperty(MarshallerProperties.JSON_MARSHAL_EMPTY_COLLECTIONS, false);
marshaller.setProperty(MarshallerProperties.JSON_VALUE_WRAPPER, "$");
Map<String, String> jsonNsMapper = new HashMap<String, String>(1);
jsonNsMapper.put("http://org/alg/ari/pnd/introspect/webservices/consumercomms", "CC");
marshaller.setProperty(MarshallerProperties.NAMESPACE_PREFIX_MAPPER, jsonNsMapper);
marshaller.marshal(result, System.out);
}
}