引自 ONJava.com 的文章，讓 Java POJO 能直接 serialize 成 JSON Format，或由 JSON Format unserialize 回 Java POJO ，透過 XStream 的 toXML 和 fromXML 相當容易及實用。
Java and JSON
from ONJava.com by firstname.lastname@example.org (Dejan Bosanac)
For one project, I started looking for a library that would enable me easy transformations between Java and JSON data. JSON in Java looks nice, but what I really want is a more automated and configurable library like those we have for XML processing. My first thought was XStream since I like its simple API, extensible architecture, powerful converters and support for annotations. After first check I found that from version 1.2 on there is a partial support for JSON (which was logical thing to expect). So, currently you can serialize your Java objects to JSON format."