Google的Gson使用

缺乏、安全感 2023-07-20 05:44 19阅读 0赞

package com.xiaomin.wechat;
    
    import com.google.gson.Gson;
    import com.google.gson.JsonArray;
    import com.google.gson.JsonObject;
    import org.junit.Test;
    
    import java.util.ArrayList;
    import java.util.HashMap;
    import java.util.List;
    import java.util.Map;
    
    /**
     * @author jat
     * @create 2020-03-31 15:16
     */
    public class TestGson {
        /**
         * pojo转json
         * 执行结果：{"username":"zhagnsan","age":18,"sex":"男"}
         */
        @Test
        public void fun(){
            Gson gson = new Gson();
            User user = new User("zhangsan",24,"男");
            String result = gson.toJson(user);
            System.out.println(result);
        }
        /**
         * json转pojo
         * 执行结果：User{username='null', age=24, sex='男'}
         */
        @Test
        public void fun2(){
            Gson gson = new Gson();
            String jsonString = "{\"name\":\"张三\",\"age\":24,\"sex\":\"男\"}";
            User user = gson.fromJson(jsonString, User.class);
            System.out.println(user);
        }
        /**
         * list转json
         * 执行结果：[{"username":"zhangsan","age":20,"sex":"男"},{"username":"lisi","age":20,"sex":"女"}]
         */
        @Test
        public void fun3(){
            Gson gson = new Gson();
            List<User> list = new ArrayList<>();
            list.add(new User("zhangsan",20,"男"));
            list.add(new User("lisi",20,"女"));
            String result = gson.toJson(list);
            System.out.println(result);
        }
        /**
         * map转json
         * 执行结果：{"sex":"男","name":"zhangsan","age":18}
         */
        @Test
        public void fun4(){
            Gson gson = new Gson();
            Map<String, Object> map = new HashMap<>();
            map.put("name","zhangsan");
            map.put("age",18);
            map.put("sex","男");
            String result = gson.toJson(map);
            System.out.println(result);
        }
        /**
         * jsonArray和jsonObject使用
         * 执行结果：[{"name":"zhangsan","age":18,"sex":"男"}]
         */
        @Test
        public void fun5(){
            JsonObject jsonObject = new JsonObject();
            JsonArray jsonArray = new JsonArray();
            jsonObject.addProperty("name","zhangsan");
            jsonObject.addProperty("age",18);
            jsonObject.addProperty("sex","男");
            jsonArray.add(jsonObject);
            System.out.println(jsonArray.toString());
        }
    }