XStream

XStream Library

Developer(s)	Codehaus
Initial release	1, 2004 (2004-01-01)
Written in	Java
Operating system	Cross-platform
License	BSD-style license
Website	http://xstream.codehaus.org/

XStream is a simple Java library to serialize objects to XML (or JSON) and back again.

XStream library

XStream stands out for its ease of use and low footprint. It uses reflection to discover the structure of the object graph to serialize at runtime. The XML it generates is very readable.

The library doesn't require modifications to objects, so it's non intrusive to use the library. It can serialize internal fields, including private and final. Supports non-public and inner classes.

Object graph serialization

When serializing an object it serializes the full object graph. Duplicate references encountered in the object-model will be maintained. For example using the following class CD

package com.thoughtworks.xstream;
public class Cd {
	private String id;

	private Cd bonusCd;

	Cd(String id, Cd bonusCd) {
		this.id = id;
		this.bonusCd = bonusCd;
	}

	Cd(String id) {
		this.id = id;
	}

	public String getId() {
		return id;
	}

	public Cd getBonusCd() {
		return bonusCd;
	}
}

and add some of these object to a list

Cd bj = new Cd("basement_jaxx_singles");
Cd mr = new Cd("maria rita");
		
List order = new ArrayList();
order.add(mr);
// adds the same cd twice (two references to the same object)
order.add(bj);
order.add(bj);

// adds itself (cycle)
order.add(order);

XStream xstream = new XStream();
xstream.alias("cd", Cd.class);
System.out.println(xstream.toXML(order));

If the above code is executed with XStream's default relative references mode, it will generate the following XML:

<list>
  <cd>
    <id>maria rita</id>
  </cd>
  <cd>
    <id>basement_jaxx_singles</id>
  </cd>
  <cd reference="../cd[2]"/>
  <list reference=".."/>
</list>

XStream is free software, distributed under a permissive, revised BSD-style licence.

Usage

• Confluence
• Apache Muse

External links

• XStream Library Home Page
• XStream, the functional transformation language for XML