• 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: mp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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  • 原文地址：https://www.cnblogs.com/LiZhiW/p/4313493.html
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