Gson的简单使用

package test;

import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

/**
 * @author
 */
public class GsonTest {

    public static void main(String args[]){
        //parseJSONObject();

        //parseJSONArray();

       // createJSONObject();

       // createJSONArray();

    }

    /**
     * 解析JSON 对象
     */
    public static void parseJSONObject(){
        String json = "{'name':'张三', 'age':25}";
        Gson gson = new Gson();
        User user = gson.fromJson(json, User.class);
        System.out.println(user);
    }

    /**
     * 生成JSON对象
     */
    public static void createJSONObject(){
        Gson gson = new Gson();
        User user = new User();
        user.name = "测试";
        user.age = 100;
        String json = gson.toJson(user);
        System.out.println(json);
    }

    /**
     * 解析JOSN数组
     */
    public static void parseJSONArray(){
        String json = "[{'name':'张三', 'age':25},{'name':'李四', 'age':25}]";
        Gson gson = new Gson();
        List<User> list = gson.fromJson(json, new TypeToken<List<User>>(){}.getType());
        Iterator<User> iter = list.iterator();
        while(iter.hasNext()){
            User user = iter.next();
            System.out.println(user);
        }
    }

    /**
     * 生成JSON数组
     */
    public static void createJSONArray(){
        Gson gson = new Gson();
        List<User> list = new ArrayList<>();
        User user = new User();
        user.name = "张三";
        user.age = 100;
        list.add(user);
        user = new User();
        user.name = "李四";
        user.age = 200;
        list.add(user);

        String json = gson.toJson(list, new TypeToken<List<User>>(){}.getType());
        System.out.println(json);
    }

    final static class User{
        public String name;
        public int age;

        @Override
        public String toString(){
            return "Nmae:"+name+"\tAge:"+age;
        }
    }
}