XML/JSON的类库，Xstream!

XML/JSON的操作类库，codehaus的xstream，很简单的在xml/json和java对象间转换。

1、所需jar包：xstream-[version].jar 和 xpp3-[version].jar 。xpp3不是必须的，也可以用标准的JAXP DOM parser 来代替，如：

<!--<br /> <br /> Code highlighting produced by Actipro CodeHighlighter (freeware)<br /> http://www.CodeHighlighter.com/<br /> <br /> -->XStream xstream = new XStream(new DomDriver()); // does not require XPP3 library

另外，通过alias可实现xml属性的支持。更多功能，请参阅 Tutorial 。

2、XML转换代码片段：
Class 转换为 xml 的代码片段:

<!--<br /> <br /> Code highlighting produced by Actipro CodeHighlighter (freeware)<br /> http://www.CodeHighlighter.com/<br /> <br /> -->XStream xstream = new XStream();

xstream.alias("person", Person.class);

xstream.alias("phonenumber", PhoneNumber.class);

Person joe = new Person("Joe", "Walnes");
joe.setPhone(new PhoneNumber(123, "1234-456"));
joe.setFax(new PhoneNumber(123, "9999-999"));
String xml = xstream.toXML(joe);

The resulting XML looks like this:

<!--<br /> <br /> Code highlighting produced by Actipro CodeHighlighter (freeware)<br /> http://www.CodeHighlighter.com/<br /> <br /> --><person>
  <firstname>Joe</firstname>
  <lastname>Walnes</lastname>
  <phone>
    <code>123</code>
    <number>1234-456</number>
  </phone>
  <fax>
    <code>123</code>
    <number>9999-999</number>
  </fax>
</person>

xml转换为java类的代码片段:

<!--<br /> <br /> Code highlighting produced by Actipro CodeHighlighter (freeware)<br /> http://www.CodeHighlighter.com/<br /> <br /> -->Person newJoe = (Person)xstream.fromXML(xml);

3、JSON

另需jar包:jettison.jar 、stax-api.jar。JSON Turorial 。

Write to json:

<!--<br /> <br /> Code highlighting produced by Actipro CodeHighlighter (freeware)<br /> http://www.CodeHighlighter.com/<br /> <br /> -->package org.sensatic.json.test;

import com.thoughtworks.xstream.XStream;
import com.thoughtworks.xstream.io.json.JettisonMappedXmlDriver;

public class WriteTest {
    public static void main(String[] args) {
        Product product = new Product("Banana", "123", 23.00);
        XStream xstream = new XStream(new JettisonMappedXmlDriver());
        xstream.alias("product", Product.class);
        System.out.println(xstream.toXML(product));    
    }
}

Read from json:

<!--<br /> <br /> Code highlighting produced by Actipro CodeHighlighter (freeware)<br /> http://www.CodeHighlighter.com/<br /> <br /> -->package org.sensatic.json.test;

import com.thoughtworks.xstream.XStream;
import com.thoughtworks.xstream.io.json.JettisonMappedXmlDriver;

public class ReadTest {
    public static void main(String[] args) {
        String json = "{\"product\":{\"name\":\"Banana\",\"id\":\"123\""
            + ",\"price\":\"23.0\"}}";
            
        XStream xstream = new XStream(new JettisonMappedXmlDriver());
        xstream.alias("product", Product.class);
        Product product = (Product)xstream.fromXML(json);
        System.out.println(product.getName());
    }
}

And that's how simple XStream is!

from:http://www.blogjava.net/josson/archive/2008/01/15/175381.html