XStream使用详解

1.Xstream介绍

(1)Xstream介绍
    Xstream是一种OXMapping 技术，是用来处理XML文件序列化的框架,在将JavaBean序列化，或将XML文件反序列化的时候，不需要其它辅助类和映射文件，使得XML序列化不再繁索。Xstream也可以将JavaBean序列化成Json或反序列化，使用非常方便。
(2)Xstream的简单例子
  1. class Person//JavaBean实体类
  2. {
  3. 	private String name;
  4. 	private int age;
  5. 	public Person(String name,int age)
  6. 	{
  7. 		this.name=name;
  8. 		this.age=age;
  9. 	}
  10. 	@Override
  11. 	public String toString()
  12. 	{
  13. 		return "Person [name=" + name + ", age=" + age + "]";
  14. 	}
  15. }
  16. public class Test
  17. {
  18. 	public static void main(String[] args)
  19. 	{
  20. 		Person bean=new Person("张三",19);
  21. 		XStream xstream = new XStream();
  22. 		//XML序列化
  23. 		String xml = xstream.toXML(bean);
  24. 		System.out.println(xml);
  25. 		//XML反序列化
  26. 		bean=(Person)xstream.fromXML(xml);
  27. 		System.out.println(bean);
  28. 		
  29. 		xstream = new XStream(new JettisonMappedXmlDriver());
  30. 		xstream.setMode(XStream.NO_REFERENCES);
  31. 		//Json序列化
  32. 		String json=xstream.toXML(bean);
  33. 		System.out.println(json);
  34. 		//Json反序列
  35. 		bean=(Person)xstream.fromXML(json);
  36. 		System.out.println(bean);
  37. 	}
  38. }
    程序运行结果：
  1. <test.Person>
  2.   <name>张三</name>
  3.   <age>19</age>
  4. </test.Person>
  5. Person [name=张三, age=19]
  6. {"test.Person":{"name":"张三","age":19}}
  7. Person [name=张三, age=19
    注意：Xstream序列化XML时需要引用的jar包：xstream-[version].jar、xpp3-[version].jar、xmlpull-[version].jar。Xstream序列化Json需要引用的jar包：jettison-[version].jar。
    使用Xstream序列化时，对JavaBean没有任何限制。JavaBean的字段可以是私有的，也可以没有getter或setter方法，还可以没有默认的构造函数。

2.Xstream的基本使用

(1)Xstream序列化XML
    Xstream序列化XML时可以允许用户使用不同的XML解析器，用户可以使用一个标准的JAXP DOM解析器或自Java6集成StAX解析器。这样用户就不需要依赖xpp3-[version].jar。
    Xstream序列化XML时，也可以对XML节点重命名。
  1. public class Test
  2. {
  3. 	public static void main(String[] args)
  4. 	{
  5. 		Person bean=new Person("张三",19);
  6. 		//XStream xstream = new XStream();//需要XPP3库
  7. 		//XStream xstream = new XStream(new DomDriver());//不需要XPP3库
  8. 		XStream xstream = new XStream(new StaxDriver());//不需要XPP3库开始使用Java6 
  9. 		xstream.alias("人",Person.class);//为类名节点重命名
  10. 		//XML序列化
  11. 		String xml = xstream.toXML(bean);
  12. 		System.out.println(xml);
  13. 		//XML反序列化
  14. 		bean=(Person)xstream.fromXML(xml);
  15. 		System.out.println(bean);
  16. 	}
  17. }
    程序运行结果：
  1. <?xml version="1.0" ?><人><name>张三</name><age>19</age></人>
  2. Person [name=张三, age=19]
(2)Xstream序列化Json
    Xstream序列化Json与序列化XML类似，例如：
  1. public class Test
  2. {
  3. 	public static void main(String[] args)
  4. 	{
  5. 		Person bean=new Person("张三",19);
  6. 		XStream xstream = new XStream(new JettisonMappedXmlDriver());//设置Json解析器
  7.         xstream.setMode(XStream.NO_REFERENCES);//设置reference模型,不引用
  8. 		xstream.alias("人",Person.class);//为类名节点重命名
  9. 		//Json序列化
  10. 		String xml = xstream.toXML(bean);
  11. 		System.out.println(xml);
  12. 		//Json反序列化
  13. 		bean=(Person)xstream.fromXML(xml);
  14. 		System.out.println(bean);
  15. 	}
  16. }
    程序运行结果：
  1. {"人":{"name":"张三","age":19}}
  2. Person [name=张三, age=19]

3.Xstream序列化重命名

(1)为包重命名：Xstream.aliasPackage()方法
  1. public class Test
  2. {
  3. 	public static void main(String[] args)
  4. 	{
  5. 		Person bean=new Person("张三",19);
  6. 		XStream xstream = new XStream();
  7. 		xstream.aliasPackage("com.lzw", "test");//为包名称重命名
  8. 		//序列化
  9. 		String xml = xstream.toXML(bean);
  10. 		System.out.println(xml);
  11. 		//反序列化
  12. 		bean=(Person)xstream.fromXML(xml);
  13. 		System.out.println(bean);
  14. 	}
  15. }
    程序运行结果：
  1. <com.lzw.Person>
  2.   <name>张三</name>
  3.   <age>19</age>
  4. </com.lzw.Person>
  5. Person [name=张三, age=19]
(2)为类重命名：Xstream.alias()方法
  1. public class Test
  2. {
  3. 	public static void main(String[] args)
  4. 	{
  5. 		Person bean=new Person("张三",19);
  6. 		XStream xstream = new XStream();
  7. 		xstream.alias("人", Person.class);//为类名节点重命名
  8. 		//序列化
  9. 		String xml = xstream.toXML(bean);
  10. 		System.out.println(xml);
  11. 		//反序列化
  12. 		bean=(Person)xstream.fromXML(xml);
  13. 		System.out.println(bean);
  14. 	}
  15. }
    程序运行结果：
  1. <人>
  2.   <name>张三</name>
  3.   <age>19</age>
  4. </人>
  5. Person [name=张三, age=19]
(3)为字段重命名：Xstream.aliasField()方法
  1. public class Test
  2. {
  3. 	public static void main(String[] args)
  4. 	{
  5. 		Person bean=new Person("张三",19);
  6. 		XStream xstream = new XStream();
  7. 		xstream.aliasField("姓名", Person.class,"name");//为类的字段节点重命名
  8. 		xstream.aliasField("年龄", Person.class,"age");//为类的字段节点重命名
  9. 		//序列化
  10. 		String xml = xstream.toXML(bean);
  11. 		System.out.println(xml);
  12. 		//反序列化
  13. 		bean=(Person)xstream.fromXML(xml);
  14. 		System.out.println(bean);
  15. 	}
  16. }
    程序运行结果：
  1. <test.Person>
  2.   <姓名>张三</姓名>
  3.   <年龄>19</年龄>
  4. </test.Person>
  5. Person [name=张三, age=19]
(4)省略集合根节点：Xstream.addImplicitCollection()方法
  1. class Person
  2. {
  3. 	private String name;
  4. 	private int age;
  5. 	private List friends;
  6. 	public Person(String name, int age, String... friends)
  7. 	{
  8. 		this.name = name;
  9. 		this.age = age;
  10. 		this.friends = Arrays.asList(friends);
  11. 	}
  12. 	@Override
  13. 	public String toString()
  14. 	{
  15. 		return "Person [name=" + name + ", age=" + age + ", friends=" + friends + "]";
  16. 	}
  17. }
  18. public class Test
  19. {
  20. 	public static void main(String[] args)
  21. 	{
  22. 		Person bean =new Person("张三",19,"李四","王五","赵六");
  23. 		XStream xstream = new XStream();
  24. 		xstream.addImplicitCollection(Person.class, "friends");//省略集合根节点
  25. 		//序列化
  26. 		String xml = xstream.toXML(bean);
  27. 		System.out.println(xml);
  28. 		//反序列化
  29. 		bean=(Person)xstream.fromXML(xml);
  30. 		System.out.println(bean);
  31. 	}
  32. }
    程序运行结果：
  1. <test.Person>
  2.   <name>张三</name>
  3.   <age>19</age>
  4.   <string>李四</string>
  5.   <string>王五</string>
  6.   <string>赵六</string>
  7. </test.Person>
  8. Person [name=张三, age=19, friends=[李四, 王五, 赵六]]
(5)把字段节点设置成属性：Xstream.useAttributeFor()方法
  1. public class Test
  2. {
  3. 	public static void main(String[] args)
  4. 	{
  5. 		Person bean =new Person("张三",19,"李四","王五","赵六");
  6. 		XStream xstream = new XStream();
  7. 		xstream.useAttributeFor(Person.class, "name");//把字段节点设置成属性
  8. 		//序列化
  9. 		String xml = xstream.toXML(bean);
  10. 		System.out.println(xml);
  11. 		//反序列化
  12. 		bean=(Person)xstream.fromXML(xml);
  13. 		System.out.println(bean);
  14. 	}
  15. }
    程序运行结果：
  1. <test.Person name="张三">
  2.   <age>19</age>
  3.   <friends class="java.util.Arrays$ArrayList">
  4.     <a class="string-array">
  5.       <string>李四</string>
  6.       <string>王五</string>
  7.       <string>赵六</string>
  8.     </a>
  9.   </friends>
  10. </test.Person>
  11. Person [name=张三, age=19, friends=[李四, 王五, 赵六]]
(6)隐藏字段：xstream.omitField()方法
  1. public class Test
  2. {
  3. 	public static void main(String[] args)
  4. 	{
  5. 		Person bean =new Person("张三",19,"李四","王五","赵六");
  6. 		XStream xstream = new XStream();
  7. 		xstream.omitField(Person.class, "friends");//把字段节点隐藏
  8. 		//序列化
  9. 		String xml = xstream.toXML(bean);
  10. 		System.out.println(xml);
  11. 		//反序列化
  12. 		bean=(Person)xstream.fromXML(xml);
  13. 		System.out.println(bean);
  14. 	}
  15. }
    程序运行结果：
  1. <test.Person>
  2.   <name>张三</name>
  3.   <age>19</age>
  4. </test.Person>
  5. Person [name=张三, age=19, friends=null]

4.Xstream注解的使用

(1)设置Xstream应用注解
    使用Xstream注解前需要对Xstream进行配置，可以使用两种方式：应用某个JavaBean类的注解或自动使用JavaBean类的注解。代码如下：
  1. XStream xstream = new XStream();
  2. xstream.processAnnotations(Person.class);//应用Person类的注解
  3. xstream.autodetectAnnotations(true);//自动检测注解
(2)重命名注解：@XStreamAlias()
  1. @XStreamAlias("人")
  2. class Person
  3. {
  4. 	@XStreamAlias("姓名")
  5. 	private String name;
  6. 	@XStreamAlias("年龄")
  7. 	private int age;
  8. 	@XStreamAlias("朋友")
  9. 	private List friends;
  10. 	public Person(String name, int age, String... friends)
  11. 	{
  12. 		this.name = name;
  13. 		this.age = age;
  14. 		this.friends = Arrays.asList(friends);
  15. 	}
  16. 	@Override
  17. 	public String toString()
  18. 	{
  19. 		return "Person [name=" + name + ", age=" + age + ", friends=" + friends + "]";
  20. 	}
  21. }
    程序运行结果：
  1. <人>
  2.   <姓名>张三</姓名>
  3.   <年龄>19</年龄>
  4.   <朋友 class="java.util.Arrays$ArrayList">
  5.     <a class="string-array">
  6.       <string>李四</string>
  7.       <string>王五</string>
  8.       <string>赵六</string>
  9.     </a>
  10.   </朋友>
  11. </人>
  12. Person [name=张三, age=19, friends=[李四, 王五, 赵六]]
(3)省略集合根节点：@XStreamImplicit
  1. class Person
  2. {
  3. 	private String name;
  4. 	private int age;
  5. 	//@XStreamImplicit//只隐藏集合根节点
  6. 	@XStreamImplicit(itemFieldName="朋友")//设置重复的节点名，可能会导致无法反序列化
  7. 	private List<String> friends;
  8. 	public Person(String name, int age, String... friends)
  9. 	{
  10. 		this.name = name;
  11. 		this.age = age;
  12. 		this.friends = Arrays.asList(friends);
  13. 	}
  14. 	@Override
  15. 	public String toString()
  16. 	{
  17. 		return "Person [name=" + name + ", age=" + age + ", friends=" + friends + "]";
  18. 	}
  19. }
    程序运行结果：
  1. <test.Person>
  2.   <name>张三</name>
  3.   <age>19</age>
  4.   <朋友>李四</朋友>
  5.   <朋友>王五</朋友>
  6.   <朋友>赵六</朋友>
  7. </test.Person>
  8. Person [name=张三, age=19, friends=[李四, 王五, 赵六]]
(4)把字段节点设置成属性：@XStreamAsAttribute
  1. class Person
  2. {
  3. 	@XStreamAsAttribute
  4. 	private String name;
  5. 	@XStreamAsAttribute
  6. 	private int age;
  7. 	private List<String> friends;
  8. 	public Person(String name, int age, String... friends)
  9. 	{
  10. 		this.name = name;
  11. 		this.age = age;
  12. 		this.friends = Arrays.asList(friends);
  13. 	}
  14. 	@Override
  15. 	public String toString()
  16. 	{
  17. 		return "Person [name=" + name + ", age=" + age + ", friends=" + friends + "]";
  18. 	}
  19. }
    程序运行结果：
  1. <test.Person name="张三" age="19">
  2.   <friends class="java.util.Arrays$ArrayList">
  3.     <a class="string-array">
  4.       <string>李四</string>
  5.       <string>王五</string>
  6.       <string>赵六</string>
  7.     </a>
  8.   </friends>
  9. </test.Person>
  10. Person [name=张三, age=19, friends=[李四, 王五, 赵六]]
(5)隐藏字段：@XStreamOmitField
  1. class Person
  2. {
  3. 	private String name;
  4. 	private int age;
  5. 	@XStreamOmitField
  6. 	private List<String> friends;
  7. 	public Person(String name, int age, String... friends)
  8. 	{
  9. 		this.name = name;
  10. 		this.age = age;
  11. 		this.friends = Arrays.asList(friends);
  12. 	}
  13. 	@Override
  14. 	public String toString()
  15. 	{
  16. 		return "Person [name=" + name + ", age=" + age + ", friends=" + friends + "]";
  17. 	}
  18. }
    程序运行结果：
  1. <test.Person>
  2.   <name>张三</name>
  3.   <age>19</age>
  4. </test.Person>
  5. Person [name=张三, age=19, friends=null]
(6)设置转换器：@XStreamConverter()
  1. class Person
  2. {
  3. 	private String name;
  4. 	private int age;
  5.         @XStreamConverter(value=BooleanConverter.class,booleans={false},strings={"男","女"})
  6. 	private boolean sex;
  7. 	public Person(String name, int age, boolean sex)
  8. 	{
  9. 		this.name = name;
  10. 		this.age = age;
  11. 		this.sex=sex;
  12. 	}
  13. 	@Override
  14. 	public String toString()
  15. 	{
  16. 		return "Person [name=" + name + ", age=" + age + ", sex=" + sex + "]";
  17. 	}
  18. }
    程序运行结果：
  1. <test.Person>
  2.   <name>张三</name>
  3.   <age>19</age>
  4.   <sex>男</sex>
  5. </test.Person>
  6. Person [name=张三, age=19, sex=true]

5.Xstream自定义的转换器

(1)Xstream自带的转换器
    Xstream内部有许多转换器，用于JavaBean对象到XML或Json之间的转换。这些转换器的详细信息网址：http://xstream.codehaus.org/converters.html
(2)使用自定义的转换器
  1. class Person
  2. {
  3. 	private String name;
  4. 	private int age;
  5. 	public Person(String name, int age)
  6. 	{
  7. 		this.name = name;
  8. 		this.age = age;
  9. 	}
  10. 	public String getName()
  11. 	{
  12. 		return name;
  13. 	}
  14. 	public void setName(String name)
  15. 	{
  16. 		this.name = name;
  17. 	}
  18. 	public int getAge()
  19. 	{
  20. 		return age;
  21. 	}
  22. 	public void setAge(int age)
  23. 	{
  24. 		this.age = age;
  25. 	}
  26. 	@Override
  27. 	public String toString()
  28. 	{
  29. 		return "Person [name=" + name + ", age=" + age + "]";
  30. 	}
  31. }
  32. public class PersonConverter implements Converter 
  33. {
  34. 	@Override//定义转换器能转换的JavaBean类型
  35. 	public boolean canConvert(Class type)
  36. 	{
  37. 		return type.equals(Person.class);
  38. 	}
  39. 	@Override//把对象序列化成XML或Json
  40. 	public void marshal(Object value, HierarchicalStreamWriter writer, 
  41. MarshallingContext context)
  42. 	{
  43. 		Person person = (Person) value;
  44.         writer.startNode("姓名");
  45.         writer.setValue(person.getName());
  46.         writer.endNode();
  47.         writer.startNode("年龄");
  48.         writer.setValue(person.getAge()+"");
  49.         writer.endNode();
  50.         writer.startNode("转换器");
  51.         writer.setValue("自定义的转换器");
  52.         writer.endNode();
  53. 	}
  54. 	@Override//把XML或Json反序列化成对象
  55. 	public Object unmarshal(HierarchicalStreamReader reader, 
  56. UnmarshallingContext context)
  57. 	{
  58. 		   Person person = new Person("",-1);
  59.            reader.moveDown();
  60.            person.setName(reader.getValue());
  61.            reader.moveUp();
  62.            reader.moveDown();
  63.            person.setAge(Integer.parseInt(reader.getValue()));
  64.            reader.moveUp();
  65.            return person;
  66. 	}
  67. }
  68. public class Test
  69. {
  70. 	public static void main(String[] args)
  71. 	{
  72. 		Person bean =new Person("张三",19);
  73. 		XStream xstream = new XStream();
  74. 		xstream.registerConverter(new PersonConverter());//注册转换器
  75. 		//序列化
  76. 		String xml = xstream.toXML(bean);
  77. 		System.out.println(xml);
  78. 		//反序列化
  79. 		bean=(Person)xstream.fromXML(xml);
  80. 		System.out.println(bean);
  81. 	}
  82. }
    程序运行结果：
  1. <test.Person>
  2.   <姓名>张三</姓名>
  3.   <年龄>19</年龄>
  4.   <转换器>自定义的转换器</转换器>
  5. </test.Person>
  6. Person [name=张三, age=19]
(3)常用的转换器接口与抽象类
    SingleValueConverter：单值转换接口
    AbstractSingleValueConverter：单值转换抽象类
    Converter：常规转换器接口

6.Xstream对象流的使用

(1)Xstream对象输出流
  1. class Person
  2. {
  3. 	private String name;
  4. 	private int age;
  5. 	public Person(String name, int age)
  6. 	{
  7. 		this.name = name;
  8. 		this.age = age;
  9. 	}
  10. }
  11. public class Test
  12. {
  13. 	public static void main(String[] args) throws IOException
  14. 	{		
  15. 		XStream xstream = new XStream();
  16. 		ObjectOutputStream out = xstream.createObjectOutputStream(System.out);
  17. 		out.writeObject(new Person("张三",12));
  18. 		out.writeObject(new Person("李四",19));
  19. 		out.writeObject("Hello");
  20. 		out.writeInt(12345);
  21. 		out.close();
  22. 	}
  23. }
    程序运行结果：
  1. <object-stream>
  2.   <test.Person>
  3.     <name>张三</name>
  4.     <age>12</age>
  5.   </test.Person>
  6.   <test.Person>
  7.     <name>李四</name>
  8.     <age>19</age>
  9.   </test.Person>
  10.   <string>Hello</string>
  11.   <int>12345</int>
  12. </object-stream>
    注意：XStream对象流是通过标准java.io.ObjectOutputStream和java.io.ObjectInputStream对象。因为XML文档只能有一个根节点,必须包装在一个序列化的所有元素 额外的根节点。 这个根节点默认 < object-stream > 上面的例子所示。 
(2)Xstream对象输出流
  1. class Person
  2. {
  3. 	private String name;
  4. 	private int age;
  5. 	public Person(String name, int age)
  6. 	{
  7. 		this.name = name;
  8. 		this.age = age;
  9. 	}
  10. 	@Override
  11. 	public String toString()
  12. 	{
  13. 		return "Person [name=" + name + ", age=" + age + "]";
  14. 	}
  15. }
  16. public class Test
  17. {
  18. 	public static void main(String[] args) throws IOException, ClassNotFoundException
  19. 	{
  20. 		String s="<object-stream><test.Person><name>张三</name><age>12</age></test.Person><int>12345</int></object-stream>";
  21. 		StringReader reader = new StringReader(s);
  22. 		XStream xstream = new XStream();
  23. 		ObjectInputStream in = xstream.createObjectInputStream(reader);
  24. 		System.out.println((Person) in.readObject());
  25. 		System.out.println(in.readInt());
  26. 	}
  27. }
    程序运行结果：
  1. Person [name=张三, age=12]
  2. 12345

7.Xstream持久化API

(1)保存JavaBean对象
  1. class Person
  2. {
  3. 	private String name;
  4. 	private int age;
  5. 	public Person(String name, int age)
  6. 	{
  7. 		this.name = name;
  8. 		this.age = age;
  9. 	}
  10. 	@Override
  11. 	public String toString()
  12. 	{
  13. 		return "Person [name=" + name + ", age=" + age + "]";
  14. 	}
  15. }
  16. public class Test
  17. {
  18. 	public static void main(String[] args) throws IOException, ClassNotFoundException
  19. 	{
  20. 		PersistenceStrategy strategy = new FilePersistenceStrategy(new File("D:\\tmp"));
  21. 		List list = new XmlArrayList(strategy);
  22. 		list.add(new Person("张三",13));//保存数据
  23. 		list.add(new Person("李四",21));
  24. 		list.add(new Person("王五",17));
  25. 	}
  26. }
    程序运行结果：如果我们检查D:\tmp目录,有三个文件:int@0.xml、int@1.xml、int@2.xml；每个对象都被序列化到XML文件里。
(2)读取并删除JavaBean对象
  1. public class Test
  2. {
  3. 	public static void main(String[] args) throws IOException, ClassNotFoundException
  4. 	{
  5. 		PersistenceStrategy strategy = new FilePersistenceStrategy(new File("D:\\tmp"));
  6. 		List list = new XmlArrayList(strategy);
  7. 		for (Iterator it = list.iterator(); it.hasNext();)
  8. 		{
  9. 			System.out.println((Person) it.next());
  10. 			it.remove();//删除对象序列化文件
  11. 		}
  12. 	}
  13. }
    程序运行结果：
  1. Person [name=张三, age=13]
  2. Person [name=李四, age=21]
  3. Person [name=王五, age=17]

8.Xstream操作Json

(1)Xstream序列化Json的重命名
  1. @XStreamAlias("人")
  2. class Person
  3. {
  4. 	@XStreamAlias("姓名")
  5. 	private String name;
  6. 	@XStreamAlias("年龄")
  7. 	private int age;
  8. 	public Person(String name, int age)
  9. 	{
  10. 		this.name = name;
  11. 		this.age = age;
  12. 	}
  13. 	@Override
  14. 	public String toString()
  15. 	{
  16. 		return "Person [name=" + name + ", age=" + age + "]";
  17. 	}
  18. }
  19. public class Test
  20. {
  21. 	public static void main(String[] args)
  22. 	{
  23. 		Person bean=new Person("张三",19);
  24. 		XStream xstream = new XStream(new JettisonMappedXmlDriver());//设置Json解析器
  25. 		xstream.autodetectAnnotations(true);
  26. 		//Json序列化
  27. 		String xml = xstream.toXML(bean);
  28. 		System.out.println(xml);
  29. 		//Json反序列化
  30. 		bean=(Person)xstream.fromXML(xml);
  31. 		System.out.println(bean);
  32. 	}
  33. }
    程序运行结果：
  1. {"人":{"姓名":"张三","年龄":19}}
  2. Person [name=张三, age=19]
    注意：Xstream序列化Json的重命名的方式与其序列化成XML的方式一样！
(2)去掉序列化Json的根节点
  1. class Person
  2. {
  3. 	private String name;
  4. 	private int age;
  5. 	public Person(String name, int age)
  6. 	{
  7. 		this.name = name;
  8. 		this.age = age;
  9. 	}
  10. 	@Override
  11. 	public String toString()
  12. 	{
  13. 		return "Person [name=" + name + ", age=" + age + "]";
  14. 	}
  15. }
  16. public class Test00
  17. {
  18. 	public static void main(String[] args)
  19. 	{
  20. 		Person bean=new Person("张三",19);
  21. 		XStream xstream = new XStream(new JsonHierarchicalStreamDriver()
  22. 		{
  23. 			public HierarchicalStreamWriter createWriter(Writer writer)
  24. 			{
  25. 				return new JsonWriter(writer, JsonWriter.DROP_ROOT_MODE);
  26. 			}
  27. 		});
  28. 		//Json序列化
  29. 		String xml = xstream.toXML(bean);
  30. 		System.out.println(xml);
  31. 	}
  32. }
    程序运行结果：
  1. { "name": "张三", "age": 19 }
    注意：去掉根节点后的Json串是不能反序列化的，因为XStream 不知道它的类型。
(3)Json的解析器区别
    前面两个例子使用了不同的Json解析器，这里说明他们的不同之处：
    1. JettisonMappedXmlDriver：是支持序列化和反序列化Json的。
    2. JsonHierarchicalStreamDriver：只支持序列化，不支持反序列化。
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posted on 2015-03-04 15:33  技术江湖-小焕  阅读(37242)  评论(3)  编辑  收藏  举报