XStream

目錄
1 XSTREAM框架 1
1.1 XSTREAM的作用 1
1.2 XSTREAM的說明 1
2 XSTREAM的使用 1
2.1 JAVABEAN轉換為XML 1
2.2 XML轉換為JAVABEAN 1
2.3 JAVABEAN轉化為JSON 1
2.4 JSON轉化為JAVABEAN 1

1 XStream框架
1.1 XStream的作用
XStream是一個開源項目，它可以實現javaBean和xml,json之間進行輕松的轉換。XStream支持將javaBean轉換為xml，同時也支持將xml轉換為javaBean，當然也可以將javaBean轉換問json，也可以將json轉換問javaBean。

1.2 XStream的說明
官網：http://xstream.codehaus.org/index.html
下載地址：http://xstream.codehaus.org/download.html
官方使用示例：http://xstream.codehaus.org/tutorial.html
打開下載地址，XStream提供了src（源碼）和bin（二進制）包下載，如果想了解學習源代碼可以下載src，如果只想使用就下載bin。下面簡紹XStream的使用。

2 XStream的使用
下載XSteam的bin包，在java項目中加入下面包。



創建java項目，創建轉換模型User和Bbirthday類，創建一個TestUser來作為測試轉換類。
XStream的toXml（）方法實現了javaBean到xml，json的轉化，fromXml（）方法實現了xml，json到javaBean的轉換。
User類

    package com.model;

import com.thoughtworks.xstream.annotations.XStreamAlias;

/**
 * @author xmong
 */
//annotation注解別名，即xml中的user節點名稱
@XStreamAlias("user")
public class User {
	
	//姓名
	public String name;
	//生日
	public Birthday birthday;
	
	public User(){
		super();
	}
	
	public User(String name, Birthday birthday) {
		this.name = name;
		this.birthday = birthday;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public Birthday getBirthday() {
		return birthday;
	}
	public void setBirthday(Birthday birthday) {
		this.birthday = birthday;
	}
		
	@Override
	public String toString() {
		return "{ name:"+this.name+"; birthday:"+this.birthday+"}";
	}

}

  

Birthday類

    package com.model;

import com.thoughtworks.xstream.annotations.XStreamAlias;
import com.thoughtworks.xstream.annotations.XStreamAsAttribute;

//annotation注解別名，即xml中的user節點名稱
@XStreamAlias("birthday")
public class Birthday {
	
	//annotation注解屬性，即xml中節點屬性
	@XStreamAsAttribute
	int year;
	@XStreamAsAttribute
	int month;
	int day;
	
	public Birthday(){
		super();
	}
	
	public Birthday(int year, int month, int day) {
		this.year = year;
		this.month = month;
		this.day = day;
	}
	
	public int getYear() {
		return year;
	}
	public void setYear(int year) {
		this.year = year;
	}
	public int getMonth() {
		return month;
	}
	public void setMonth(int month) {
		this.month = month;
	}
	public int getDay() {
		return day;
	}
	public void setDay(int day) {
		this.day = day;
	}
	
	@Override
	public String toString() {
		return "{year:"+this.year+"; month"+this.month+"; day"+this.day+"}";
	}

}
  

2.1 JavaBean轉化為XML

TestUser類

    package com.model;

import com.thoughtworks.xstream.XStream;

/**
 * @author xmong
 */
public class TestUser {
	
	/**
	 * javaBean轉換為xml
	 */
	public void test1(){
		
		//創建user對象
		User user = new User();
		user.setName("xmong");
		user.setBirthday(new Birthday(1990, 10, 20));
		
		//創建xstream
		XStream xstream = new XStream();
		//XStream xstream = new XStream(new DomDriver());
		//XStream xstream = new XStream(new StaxDriver());

		//加載annotation注解
		xstream.processAnnotations(User.class);
		
		System.out.println(xstream.toXML(user));
		
	}

       public static void main(String[] args) {
		TestUser tu = new TestUser();
		tu.test1();
	}
	
}
  

輸出結果：

    <user>
  <name>xmong</name>
  <birthday year="1990" month="10">
    <day>20</day>
  </birthday>
</user>
  

如果使用

    XStream xstream = new XStream(new DomDriver())
  

創建XSteam對象那么輸出的結果同上。
如果使用

    XStream xstream = new XStream(new StaxDriver())
  

來創建XStream對象，輸出的結果：

    <?xml version="1.0" ?><user><name>xmong</name><birthday year="1990" month="10"><day>20</day></birthday></user>
  

2.2 XML轉化為JavaBean

在TestUser的main方法調用test2方法

    /**
	 * XML轉換為JavaBean
	 */
	public void test2(){
		
		//創建user對象
		User user = new User();
		user.setName("xmong");
		user.setBirthday(new Birthday(1990, 10, 20));
		
		//創建xstream
		XStream xstream = new XStream();
		//加載annotation注解
		xstream.processAnnotations(User.class);
		
		String xml = xstream.toXML(user);
		
		System.out.println(xml);
		
		System.out.println("===================");
		
		System.out.println((User)xstream.fromXML(xml));
		
	}

	public static void main(String[] args) {
		TestUser tu = new TestUser();
		tu.test2();
	}


  

輸出結果

    <user>
  <name>xmong</name>
  <birthday year="1990" month="10">
    <day>20</day>
  </birthday>
</user>
===================
{ name:xmong; birthday:{year:1990; month10; day20}}
  

2.3 JavaBean轉化為Json

    /**
	 * javaBean轉換為json
	 */
	public void test3(){
		
		//創建user對象
		User user = new User();
		user.setName("xmong");
		user.setBirthday(new Birthday(1990, 10, 20));
		
		//創建xstream，傳入轉換驅動類JettisonMappedXmlDriver
		XStream xstream = new XStream( new JettisonMappedXmlDriver());
		//設置user類的json別名
		xstream.alias("user", User.class);
		
		System.out.println(xstream.toXML(user));
		
	}


	public static void main(String[] args) {
		TestUser tu = new TestUser();
		tu.test3();
	}
  

輸出結果

    {"user":{"name":"xmong","birthday":{"year":1990,"month":10,"day":20}}}
  

    /**
	 * javaBean轉換為json
	 */
	public void test4(){
		
		//創建user對象
		User user = new User();
		user.setName("xmong");
		user.setBirthday(new Birthday(1990, 10, 20));
		
		//創建xstream，傳入轉換驅動類JsonHierarchicalStreamDriver
		XStream xstream = new XStream( new JsonHierarchicalStreamDriver());
		/*//去除根節點
		XStream xstream = new XStream(new JsonHierarchicalStreamDriver() {
		    public HierarchicalStreamWriter createWriter(Writer writer) {
		        return new JsonWriter(writer, JsonWriter.DROP_ROOT_MODE);
		    }
		});
		*/

		//設置user類的json別名
		xstream.alias("user", User.class);
		
		System.out.println(xstream.toXML(user));
		
	}

	public static void main(String[] args) {
		TestUser tu = new TestUser();
		tu.test4();
	}
  

輸出結果

    {"user": {
  "name": "xmong",
  "birthday": {
    "year": 1990,
    "month": 10,
    "day": 20
  }
}}
  

如果使用

    XStream xstream = new XStream(new JsonHierarchicalStreamDriver() {
		    public HierarchicalStreamWriter createWriter(Writer writer) {
		        return new JsonWriter(writer, JsonWriter.DROP_ROOT_MODE);
		    }
		});
  

創建XStream對象，那么java對象轉換成的json會去除根節點。
輸出結果

    {
  "name": "xmong",
  "birthday": {
    "year": 1990,
    "month": 10,
    "day": 20
  }
}
  

2.4 Json轉化為JavaBean

    /**
	 * json轉換為javaBean
	 */
	public void test5(){
		
		//創建user對象
		User user = new User();
		user.setName("xmong");
		user.setBirthday(new Birthday(1990, 10, 20));
		
		//創建xstream，傳入轉換驅動類JettisonMappedXmlDriver
		XStream xstream = new XStream( new JettisonMappedXmlDriver());
		//設置user類的json別名
		xstream.alias("user", User.class);
		
		String json = xstream.toXML(user);
		
		System.out.println(json);
		System.out.println("================");
		System.out.println(xstream.fromXML(json));
		
	}
	
	public static void main(String[] args) {
		TestUser tu = new TestUser();
		tu.test5();
	}
  

輸出結果

    {"user":{"name":"xmong","birthday":{"year":1990,"month":10,"day":20}}}
================
{ name:xmong; birthday:{year:1990; month10; day20}}
  

XStream小使用