This is a continuation from this post: Xml Serialization in Java using Simple

Example 4 – Serializing a list of objects that inherit from Person

Lets create some objects that inherit from Person. I looked at some documentation to try to get it right the first time. And then I hoped that it would just work….

import org.simpleframework.xml.Element;
import org.simpleframework.xml.Root;

@Root
public class Person
{
	@Element(name="FirstName")
	private String _FirstName = "";

	@Element(name="LastName")
	private String _LastName = "";

	public String getFirstName()
	{
		return _FirstName;
	}

	public void setFirstName(String inFirstName)
	{
		_FirstName = inFirstName;
	}

	public String getLastName()
	{
		return _LastName;
	}

	public void setLastName(String inLastName)
	{
		_LastName = inLastName;
	}
}

import java.util.ArrayList;
import java.util.List;
import org.simpleframework.xml.ElementList;
import org.simpleframework.xml.Root;

@Root
public class People 
{
	@ElementList(inline=true)
	List<Person> List = new ArrayList<Person>();
}

I didn’t want to get too complex so I only added a single item to Patient, a list of Symptoms.

import java.util.ArrayList;
import java.util.List;
import org.simpleframework.xml.ElementList;

public class Patient extends Person
{
	@ElementList(entry = "Symptom", inline = true)
	public List<String> Symptoms = new ArrayList<String>();
}

For the Physician, again to keep it simple, I only added a list of Hospitals.

import java.util.ArrayList;
import java.util.List;
import org.simpleframework.xml.ElementList;

public class Physician extends Person
{
	@ElementList(entry = "Hospital", inline = true)
	public List<String> Hospitals = new ArrayList<String>();
}

And here is the main method where I create the instances and serialize them.

import java.io.File;
import org.simpleframework.xml.Serializer;
import org.simpleframework.xml.core.Persister;

public class Run
{
	public static void main(String[] args) throws Exception
	{
		People people = new People();
		
		Patient p1 = new Patient();
		p1.setFirstName("Jared");
		p1.setLastName("Barneck");
		p1.Symptoms.add("Runny nose");
		p1.Symptoms.add("Congestion");
		people.List.add(p1);

		Physician p2 = new Physician();
		p2.setFirstName("Mike");
		p2.setLastName("Michaels");
		p2.Hospitals.add("Intermount Health Care");
		p2.Hospitals.add("St. Marks");
		people.List.add(p2);
		
		Serializer serializer = new Persister();
		File file = new File("people.xml");

		serializer.write(people, file);
	}
}

And yeah! This worked. Here is the Xml.

<people>
   <person class="Patient">
      <FirstName>Jared</FirstName>
      <LastName>Barneck</LastName>
      <Symptom>Runny nose</Symptom>
      <Symptom>Congestion</Symptom>
   </person>
   <person class="Physician">
      <FirstName>Mike</FirstName>
      <LastName>Michaels</LastName>
      <Hospital>Intermount Health Care</Hospital>
      <Hospital>St. Marks</Hospital>
   </person>
</people>

There you go.

There are a lot more examples here:
Simple Xml Serialization Tutorial