Android and Xml Serialization with Simple

Xml serialization is almost becoming a standard requirement for a language these days and so as I have been taking an Android class and I couldn’t find an Xml Serialization library as part of Android by default, I set out in search of one.

I came across a java XML Serialization project called Simple.

So here is a quick entry-level example of how to use Simple in an Android development project.

Note: This walk-thru assumes you are using Eclipse.

Step 1 – Create a new Android Project

  1. Go to File | New Project and select Android.
  2. Provide a Project Name.
  3. Select the minimum build target.
  4. Provide a Package name.
  5. Click Finish.

Step 2 – Download Simple

  1. Go to the Simple download page: http://simple.sourceforge.net/download.php
  2. Extract the zip file.

Step 3 – Add the Simple library to your project

  1. Create a folder called libs in your project.
  2. Copy the jar file called simple-xml-2.6.2.jar to the libs directory you just created.Note: Be aware your version may be newer than 2.6.2.
  3. In Eclipse, right-click on simple-xml-2.6.2.jar (if it doesn’t show up refresh) and choose Build Path | Add to Build Path.

Step 4 – Create an Serializeable object

  1. Right-click on your package and choose New | Class.
  2. Provide a class name and click ok.
  3. The following is an example Person class:Person.java
    package org.jaredbarneck.cs6890;
    
    import org.simpleframework.xml.Element;
    import org.simpleframework.xml.Root;
    
    @Root
    public class Person
    {
    
    	public Person()
    	{
    	}
    
    	public Person(String inFirstName, String inLastName)
    	{
    		SetFirstname(inFirstName);
    		SetLastname(inLastName);
    	}
    
    	@Element
    	private String FirstName;
    
    	public String GetFirstName()
    	{
    		return FirstName;
    	}
    
    	public void SetFirstname(String inFirstName)
    	{
    		FirstName = inFirstName;
    	}
    
    	@Element
    	private String LastName;
    
    	public String GetLastName()
    	{
    		return LastName;
    	}
    
    	public void SetLastname(String inLastName)
    	{
    		LastName = inLastName;
    	}
    
    	@Override
    	public boolean equals(Object inObject)
    	{
    		if (inObject instanceof Person)
    		{
    			Person inPerson = (Person)inObject;
    			return this.FirstName.equalsIgnoreCase(inPerson.FirstName)
    				&& this.LastName.equalsIgnoreCase(inPerson.LastName);
    		}
    		return false;
    	}
    }
    

Step 5 – Serialize and Deserialize in your main Activity

  1. Add the following code to your main Activity:Note: Code should be clear and is commented.PersonActivity.java
    package org.jaredbarneck.cs6890;
    
    import java.io.File;
    
    import org.simpleframework.xml.Serializer;
    import org.simpleframework.xml.core.Persister;
    
    import android.app.Activity;
    import android.os.Bundle;
    
    public class PersonActivity extends Activity
    {
    	public void onCreate(Bundle savedInstanceState)
    	{
    		super.onCreate(savedInstanceState);
    		setContentView(R.layout.main);
    
    		// Create a Person object
    		Person person1 = new Person("John", "Johnson");
    
    		// Create a file to save to and make sure to use the path provided from
    		// getFilesDir().getPath().
    		File xmlFile = new File(getFilesDir().getPath() + "/Person.xml");
    
    		// Serialize the Person
    
    		try
    		{
    			Serializer serializer = new Persister();
    			serializer.write(person1, xmlFile);
    		}
    		catch (Exception e)
    		{
    			e.printStackTrace();
    		}
    
    		// Create a second person object
    		Person person2 = null;
    
    		// Deserialize the Person
    		if (xmlFile.exists())
    		{
    			try
    			{
    				Serializer serializer = new Persister();
    				person2 = serializer.read(Person.class, xmlFile);
    			}
    			catch (Exception e)
    			{
    				e.printStackTrace();
    			}
    		}
    
    		boolean b = person1.equals(person2);
    	}
    }
    

Go ahead and try this in your Android emulator and step through it with a debugger.

You have now successfully implemented Xml Serialization in Java on Android using Simple.

5 Comments

  1. Abhishek says:

    Currently, person.xml file is created with root tag . How to create as a root tag(means first letter with capital)?

    I also want to include namespace with root tag. For example -

    Is it possible to achieve with "Simple" library?

  2. Shaon says:

    If i have a list of persons. How would i loop through the xml elements and put the read values in a arraylist, i mean add to arraylist the below object:
    person2 = serializer.read(Person.class, xmlFile)

  3. hong says:

    Where should I put my xml file ? and what will I do when I need to read the xml from thhp api ? thank

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