fastjson中List和JSONArray的相互转换

Posted 2022-11-28 晓锋残月

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

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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。