fastjson中List和JSONArray的相互转换

╰半夏微凉° 2022-02-13 02:34 620阅读 0赞

## 1.fastjson中List和JSONArray的相互转换 ##

(1)`List`转换为`JSONArray`

List<T> list = new ArrayList<T>();
    JSONArray array= JSONArray.parseArray(JSON.toJSONString(list))；

(2)`JSONArray`转换为`List`

JSONArray array = new JSONArray();
    List<EventColAttr> list = JSONObject.parseArray(array.toJSONString(), EventColAttr.class);

以上内容参考：[CSDN博客][CSDN]

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## 2.实例 ##

创建一个User.java

public class User { 
    
        private String name;
        private int age;
    
        public String getName() { 
            return name;
        }
    
        public void setName(String name) { 
            this.name = name;
        }
    
        public int getAge() { 
            return age;
        }
    
        public void setAge(int age) { 
            this.age = age;
        }
    
        @Override
        public String toString() { 
            return "User [name=" + name + ", age=" + age + "]";
        }
    }

（1）`List`转换为`JSONArray`

// list--->Json字符串-->JSONArray
        @Test
        public void test2(){ 
            //准备工作
            List<User> list = new ArrayList<User>();
            User user1 = new User();
            user1.setName("zhangsan");
            user1.setAge(14);
            User user2 = new User();
            user2.setName("lisi");
            user2.setAge(24);
            list.add(user1);
            list.add(user2);
    
            //转换为Json字符串
            String string = JSON.toJSONString(list);
            System.out.println("String为："+string+",其类型为："+string.getClass());
            //转换为JSONArray
            JSONArray array = JSON.parseArray(JSON.toJSONString(list));
            System.out.println("JSONArray为："+array+",其类型为："+array.getClass());
    
        }

运行结果：

String为：[{"age":14,"name":"zhangsan"},{"age":24,"name":"lisi"}],其类型为：class java.lang.String
    JSONArray为：[{"name":"zhangsan","age":14},{"name":"lisi","age":24}],其类型为：class com.alibaba.fastjson.JSONArray

(2)`JSONArray`转换为`List`

// JSONArray--->Json字符串 ----->list
        @Test
        public void test3(){ 
            //准备工作
            List<User> list = new ArrayList<User>();
            User user1 = new User();
            user1.setName("zhangsan");
            user1.setAge(14);
            User user2 = new User();
            user2.setName("lisi");
            user2.setAge(24);
            list.add(user1);
            list.add(user2);
            JSONArray array = JSON.parseArray(JSON.toJSONString(list));
    
            //转换为Json字符串
            String string = array.toJSONString(array);
            System.out.println("String为："+string+",其类型为："+string.getClass());
            //转换为list
            List<User> list2 = JSON.parseArray(string, User.class);
            System.out.println("list为："+list2+",其类型为："+list2.getClass());
        }

运行结果：

String为：[{"name":"zhangsan","age":14},{"name":"lisi","age":24}],其类型为：class java.lang.String
    list为：[User [name=zhangsan, age=14], User [name=lisi, age=24]],其类型为：class java.util.ArrayList

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## 3.小结 ##

以上内容如果存在错误，请指正。

[CSDN]: https://blog.csdn.net/u014736629/article/details/80521581