fastjson json-＞map_fastjson读取json map-优快云博客

本文链接：https://blog.youkuaiyun.com/awesometime/article/details/109516936

本文介绍了一个使用Java和fastjson库将JSON字符串转换为Map的具体实例。示例中定义了一个Student类，并通过JSON.parseObject方法将包含多个Student对象的JSON字符串转换为Map。此外，还展示了如何遍历这个Map并进行增删操作。

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JSON.parseObject 之json->map

package testMap;

import java.util.Map;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.TypeReference;

public class Student {
    String name;

    Integer age;

    public Student(String name, Integer age) {
        this.name = name;
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    @Override
    public String toString() {
        return "Student{" +
                "name='" + name + '\'' +
                ", age=" + age +
                '}';
    }

    public static void main(String[] args) {
        String json = "{\"1\":{\"name\":\"zhangsan\",\"age\":2},\"2\":{\"name\":\"lisi\",\"age\":26}}";
        Map<String, Student> map;
        map = JSON.parseObject(json, new TypeReference<Map<String, Student>>() {
        });
        System.out.println(map.toString());
        System.out.println(map.get("1"));

        //最常见也是大多数情况下用的最多的，一般在键值对都需要使用
        for (Map.Entry<String, Student> entry : map.entrySet()) {
            String mapKey = entry.getKey();
            Student mapValue = entry.getValue();
            System.out.println(mapKey + " : " + mapValue);
        }

        // map.put
        map.put("third", new Student("wangwu", 23));
        System.out.println(map);
    }

}

输出

{1=Student{name='zhangsan', age=2}, 2=Student{name='lisi', age=26}}

Student{name='zhangsan', age=2}

1 : Student{name='zhangsan', age=2}
2 : Student{name='lisi', age=26}

{1=Student{name='zhangsan', age=2}, 2=Student{name='lisi', age=26}, third=Student{name='wangwu', age=23}}