【java】Map List Bean 转 JSON

需要jar

json-lib.jar

http://download.youkuaiyun.com/detail/yjqyyjw/9800968

User

package demo;

public class User {
	private String username;
	private String password;
	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;
	}
}

测试

package demo;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import net.sf.json.JSONArray;
import net.sf.json.JSONObject;

public class JsonTest {
	static List<User> list;
	static Map<String, Object> map;
	static User user1;
	static User user2;

	public static void main(String[] args) {
		new JsonTest().initUser();
		/**
		 *  A:普通JavaBean转成json格式
		 *  1.转成JSONArray类型
		 */
		JSONArray json = JSONArray.fromObject(user1);
		// [{"password":"1111","username":"yjq1"}]
		// 在js文件取数据
		// $.getJSON("http://localhost:8080/jQueryDemo/servlet/listervlet",null,function(data)
		// {
		// alert(data[0].username);
		// alert(data[0].password);
		// });
		/**
		 *  2.转成JSONObject类型
		 */
		JSONObject jsonObj = JSONObject.fromObject(user1);
		// {"password":"1111","username":"yjq1"}
		// 在js文件取数据 alert(data.username); alert(data.password);

		/**
		 *  B:List转成json格式
		 *  1.转成JSONArray类型
		 */
		JSONArray jsonList = JSONArray.fromObject(list);
		// [{"password":"1111","username":"yjq1"},{"password":"2222","username":"yjq2"}]
		// js中取数据：alert(alert(data[0].username));
		/**
		 *  2.转成JSONObject类型
		 */
		JSONObject jsonListObj = new JSONObject();
		jsonObj.put("list", list);
		jsonObj.put("u", user1);
		// {"list":[{"password":"1111","username":"yjq1"},{"password":"2222","username":"yjq2"}],"u":{"password":"1111","username":"yjq1"}}
		// js中取数据：alert(data.list[0].username);

		/**
		 *  C:Map转成json格式
		 *  1.转成JSONArray类型
		 */
		JSONArray jsonMap = JSONArray.fromObject(map);
		// [{"list":[{"password":"1111","username":"yjq1"},{"password":"2222","username":"yjq2"}],"u":{"password":"1111","username":"yjq1"}}]
		// js中取数据：alert(data[0].list[0].username);
		/**
		 *  2.转成JSONObject类型
		 */
		JSONObject jsonMapObj = JSONObject.fromObject(map);
		// {"user":[{"password":"1111","username":"yjq1"},{"password":"2222","username":"yjq2"}],"u":{"password":"1111","username":"yjq1"}}
		// js中取数据：alert(data.user[0].username);
	}

	public void initUser() {
		user1 = new User();
		user1.setUsername("yjq1");
		user1.setPassword("1111");
		user2 = new User();
		user2.setUsername("yjq2");
		user2.setPassword("2222");
		list = new ArrayList<User>();
		list.add(user1);
		list.add(user2);
		map = new HashMap<String, Object>();
		map.put("list", list);
		map.put("user1", user1);
	}
}