JAXB Unmarshalling polymorphic objects - collections?

Question

I have got XML as following :

<Temp NAME="bobo"> 
    <elem1 />
    <elem2>
        <Attri1 ID="123" />
    </elem2>
    <elem3>
        <Attri2 MOM="9" ID="7" SSS="2" />
    </elem3>
    <elem3>
         <Attri3 MOM="44" ID="4" DSC="First Test"/>
    </elem3>
</Temp>

I'm using annotations to map to java classes :

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

    @XmlElements({
        @XmlElement(name="elem1",type=elem.class),
        @XmlElement(name="elem2",type=elem.class)})
    public ArrayList<elem> elms;
}

---

public class elem {
...
}

---

public class elem1 extends elem{
...
}

---

public class elem2 extends elem{
...
}

---

public class elem3 extends elem{
...
}

In each element there can be lots of attributes.

Can someone please help me how to annotate the java classes correctly ?

Let me sharpen my question. I need to build from this XML a java objects that will have 3 parameters : name of the first element(p1) , name of child element(p2), map values (p3).

The XML above will generate 4 java elem objects as following:

all java objects type is elem!

obj1 :

p1 = elem1
p2 = null
p3 = null

obj2 :

p1 = elem2
p2 = Attri1
p3 =  map:   key   value
             (ID,  123)

obj3 :

p1 = elem3
p2 = Attri2
p3 =  map:   key   value
             (MOM,  9)
             (ID,  7)
             (SSS,  2)

obj4 :

p1 = elem3
p2 = Attri3
p3 =  map:   key   value
             (MOM,  44)
             (ID,  4)
             (DSC,  First Test)

Thanks in advance! Boris.

Answer 1

Well, you need to have a schema definition for your xml which covers all your cases. If indeed you need dynamic structure you need to build it in a different way with key & value pairs. For ex:

< Attribute >

<name >ID</name >
<value > 123</value >

OR

< Attribute name="ID" value="123" >

This will give you a collection of attributes for each element. This can be represented in your schema. Once you have the schema, you can generate or create your objects