JSON 和 List、Map集合结合使用

<strong><span style="font-size:24px;color:#ff0000;">创建User类：</span></strong>

package lgson;

import java.util.ArrayList;
import java.util.HashMap;

/*
 * 自定义一个User类
 * 
 * */
public class User {
	public int id;
	public String Name;
	public int age;
	public ArrayList<String> books;
	public HashMap<String, String> booksMap;
	public String email;
}

<span style="font-size:24px;color:#ff0000;"><strong>测试类：</strong></span>

package lgson_get_test;

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

import com.google.gson.Gson;


public class Get_Test{
		public static void main(String [] args){
		Gson gson = new Gson();
		User user = new User();
		user.id = 1;
		user.Name = "陈郑游";
		user.age = 22;
		user.email = "[e-mail]";			
		System.out.println("第一次输出JSON数据：" + gson.toJson(user) + "\n");
		
		List<String> books = new ArrayList<String>();
		books.add("数学");  
        books.add("语文");  
        books.add("英语");  
        books.add("物理");  
        books.add("化学");  
        books.add("生物");  
		user.books=(ArrayList<String>) books;
		System.out.println("第二次输出JSON数据：" + gson.toJson(user));
		
		HashMap<String, String> booksMap = new HashMap<String, String>();
		//map.put(key, value);
		booksMap.put("1", "数学");  
        booksMap.put("2", "语文");  
        booksMap.put("3", "英语");  
        booksMap.put("4", "物理");  
        booksMap.put("5", "化学");  
        booksMap.put("6", "生物");  
        user.booksMap=booksMap;
        System.out.println("第三次输出JSON数据：" + gson.toJson(user) + "\n");
        
		String string = new String();
		//输出的字符串使用Gson转换成User对象
		string.format(string, User.class);
		
		System.out.println("类名：" + user.getClass());
		System.out.println("年龄：" + user.age);
		System.out.println("名字：" + user.Name);
		System.out.println("邮箱：" +user.email);
		System.out.println("books:" + user.books);
		System.out.println("books size :" + user.books.size());
		System.out.println("booksMap:" + user.booksMap);

	    }
}