Java UnMarshall XML gives null objects

Question

UnMarshalling XML gives null java objects.

XML :

<?xml version="1.0" encoding="UTF-8"?>
<Items>
<Item Name="John"/>
<Item Name="Jason"/>
</Items>

Items class :

@XmlRootElement(name = "Items")
@XmlAccessorType(XmlAccessType.FIELD)
public class Items{

    @XmlElement
    private List<Item> item; 

    public List<Item> getItem() {
    return this.Item;
}

}

Item class :

@XmlAccessorType(XmlAccessType.FIELD)
@XmlRootElement(name = "Item")
public class Item{

    @XmlAttribute
    private String name;

   public String getName() {
    return this.Name;
   }

}

Java Code that UnMarshalls : Here result.getBody gives XML String

ResponseEntity<String> result = restTemplate.exchange(uri, HttpMethod.GET, entity, String.class);

 
        JAXBContext jaxbContext = JAXBContext.newInstance(Items.class);
        Unmarshaller jaxbUnmarshaller = jaxbContext.createUnmarshaller();

        
        Items itResult =  (Items) jaxbUnmarshaller.unmarshal(new StringReader(result.getBody()));

Item object always comes null. How to unmarshall the xml correctly ? Thanks in Advance. :

Answer 1

Use the following classes :

Item.java

@XmlRootElement(name = "Item")
public class Item
{


   private String name;

   public String getName() 
   {
      return this.name;
   }

   @XmlAttribute(name = "Name" )
   public void setName( String name )
   {
       this.name = name;
   }

}

Items.java

@XmlRootElement(name = "Items")
public class Items
{

    @XmlElementWrapper( name = "Items")
    private List<Item> items = new ArrayList<Item>();


    public List<Item> getItemList() 
    {
       return this.items;
    }

    @XmlElement(name = "Item")
    public void setItemList( List<Item> items )
    {
        this.items = items;
    }

}

Test.java

public class Test
{
    public static void main( String... args )
    {
        try
        {
            JAXBContext jaxbContext = JAXBContext.newInstance( Items.class );
            Unmarshaller jaxbUnmarshaller = jaxbContext.createUnmarshaller();
            Items itResult =  (Items) jaxbUnmarshaller.unmarshal( new File( "Items.xml" ) );

            if ( itResult != null )
            {
                List<Item> items = itResult.getItemList();
                for ( Item item : items )
                {
                    System.out.println( item.getName() );
                }
            }
        }
        catch ( Exception e )
        {
            e.printStackTrace();
        }
    }

}

You should get the Items object which contains Item s.

Changes I made:

a) You need an @XmlElementWrapper on the list which says that the Items is a wrapper around Items.

b) Move the @XmlAttribute to setter in Item.java

c) Move the @XmlElement to setter in Items.java