JSON和JAVA对象之间的转换
    发现一个比较好用的JSON和JAVA对象之间的转换工具。名字叫GSON.
    gson网址:http://code.google.com/p/google-gson/

    参考：

    原文 -  [url]http://www.mkyong.com/java/how-do-convert-java-object-to-from-json-format-gson-api/ [/url]

    Json Official site – http://www.json.org/

    Json in Wiki – http://en.wikipedia.org/wiki/JSON

    Google Gson – http://code.google.com/p/google-gson/

    Gson User Guide - http://sites.google.com/site/gson/gson-user-guide     

    很简单的使用：
     toJson：转Object到json
     fromJson：转json到Object
上面的两个API基本够日常使用了。其他的自己看吧。


    实例代码：
    pojo:
   

class UserInfo{
	String username;
	String password;
	List<String> subName;
	Map<String,String> map;
	Privileges[] privileges;
	Privileges privilegesObj;
	
	{
		username = "zhangsan";
		password = "zhangsnaPass";
		subName = new ArrayList<String>();
		subName.add("aabc");
		subName.add("lisi");
		map = new HashMap<String,String>();
		map.put("u1", "v1");
		map.put("u2", "v2");
		privileges = new Privileges[2];
		Privileges priv1 = new Privileges();
		priv1.setPriviName("delete img res");
		Privileges priv2 = new Privileges();
		priv2.setPriviName("add music res");
		privileges[0]=priv1;
		privileges[1]=priv2;
		privilegesObj = new Privileges();
		privilegesObj.setPriviName("test res iffo");
	}
        public String getUsername() {
 		return username;
	}

	public void setUsername(String username) {
		this.username = username;
	}

	public String getPassword() {
		return password;
	}

	public void setPassword(String password) {
		this.password = password;
	}

	public List<String> getSubName() {
		return subName;
	}

	public void setSubName(List<String> subName) {
		this.subName = subName;
	}

	public Map<String, String> getMap() {
		return map;
	}

	public void setMap(Map<String, String> map) {
		this.map = map;
	}

	public Privileges[] getPrivileges() {
		return privileges;
	}

	public void setPrivileges(Privileges[] privileges) {
		this.privileges = privileges;
	}
    }

   

class Privileges{
	String priviName;

	public String getPriviName() {
		return priviName;
	}

	public void setPriviName(String priviName) {
		this.priviName = priviName;
	}
	
	
}

测试：

public static void main(String[] args) {
		Gson gson = new Gson();
		String json = null;
		
		UserInfo userinfo = new UserInfo();
		json = gson.toJson(userinfo);
		System.out.println("userinfo json str:"+json);
		//userinfo json str:{"username":"zhangsan","password":"zhangsnaPass","subName":["aab","lisi"],"map":{"u2":"v2","u1":"v1"},"privileges":[{"priviName":"delete img res"},{"priviName":"add music res"}],"privilegesObj":{"priviName":"test res iffo"}}
		
		json = "{\"username\":\"zhangsan\",\"password\":\"zhangsnaPass\",\"subName\":[\"list1\",\"list2\"],\"map\":{\"u2\":\"v2\",\"u1\":\"v1\"},\"privileges\":[{\"priviName\":\"delete img res\"},{\"priviName\":\"add music res\"}],\"privilegesObj\":{\"priviName\":\"test res iffo\"}}";
		userinfo = gson.fromJson(json, UserInfo.class);
		System.out.println(userinfo);
		
	}

非常简单的使用，toJson、fromJson基本够用。其他的自己研究吧。