JAXB HashMap unmappable

I want to convert a HashMap in a POJO class to XML. I tried using the XmlAdapter but it results in only the key and value pairs of the HashMap being the attributes of the XML Elements. I need the Key to be the Element itself and the value of the HashMap to be the value of the element. For instance, I need the following XML:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?> <cart> <supervisor_id>555</supervisor_id> <payments> <payment sequence="1"> <amount>123.45</amount> <billing_method>12345</billing_method> <form>card</form> <delivery_mode>Q</delivery_mode> </payment> <payment sequence="2"> <amount>123.45</amount> <person_id>2333</person_id> <form>cash</form> <delivery_mode>Q</delivery_mode> </payment> </payments> </cart> 

I created the following classes: MyMapType holds a list of MyMapEntryType class which has two fields namely Key and Value. How do I change the Key element to be @XmlElement and assign the value field to the Key field?

Here are my source files.

MyMapType.java

import java.util.ArrayList; import java.util.List; public class MyMapType { private List<MyMapEntryType> entry = new ArrayList<MyMapEntryType>(); public List<MyMapEntryType> getEntry() { return entry; } public void setEntry(List<MyMapEntryType> entry) { this.entry = entry; } } 

MyMapEntryType.java

import javax.xml.bind.annotation.XmlAccessType; import javax.xml.bind.annotation.XmlAccessorType; import javax.xml.bind.annotation.XmlAttribute; import javax.xml.bind.annotation.XmlValue; @XmlAccessorType(XmlAccessType.FIELD) public class MyMapEntryType { @XmlAttribute private String key; @XmlValue private String value; public String getKey() { return key; } public void setKey(String key) { this.key = key; } public String getValue() { return value; } public void setValue(String value) { this.value = value; } } 

Please also find the adapter class:

MyMapAdapter.java

import java.util.HashMap; import java.util.Map; import java.util.Map.Entry; import javax.xml.bind.annotation.adapters.XmlAdapter; public class MyMapAdapter extends XmlAdapter<MyMapType, Map<String, String>> { @Override public MyMapType marshal(Map<String, String> map) throws Exception { MyMapType myMapType = new MyMapType(); for(Entry<String, String> entry : map.entrySet()) { MyMapEntryType myMapEntryType = new MyMapEntryType(); myMapEntryType.setKey(entry.getKey()); myMapEntryType.setValue(entry.getValue()); myMapType.getEntry().add(myMapEntryType); } return myMapType; } @Override public Map<String, String> unmarshal(MyMapType map) throws Exception { HashMap<String, String> hashMap = new HashMap<String, String>(); for(MyMapEntryType myEntryType : map.getEntry()) { hashMap.put(myEntryType.getKey(), myEntryType.getValue()); } return hashMap; } } 

This is the class which has the HashMap field:

XmlElementMap.java

@XmlAccessorType(XmlAccessType.FIELD) public class XmlElementMap { @XmlAttribute(name="sequence") private int sequence; @XmlJavaTypeAdapter(MyMapAdapter.class) private Map<String, String> map = new HashMap<String, String>(); public int getSequence() { return sequence; } public void setSequence(int sequence) { this.sequence = sequence; } public Map<String, String> getMap() { return map; } public void setMap(Map<String, String> map) { this.map = map; } } 

Please advise on how to achieve this.

Regards,
-Anand

Currently it produces the following output: