json

package jsonTask;

import com.google.gson.Gson;

import java.util.HashMap;

public class Demo2Gson {
    public static void main(String[] args) {

        String jsonStr="{\"id\":\"1500100001\",\"name\":\"施笑槐\",\"age\":\"22\",\"gender\":\"女\",\"clazz\":\"文科六班\"}";
        System.out.println(jsonStr);
        //Gson解析json字符串
        Gson gson = new Gson();
        //传入两个参数，一个字符串，一个解析的格式，用反射来写
        HashMap<String, String> map = new HashMap<String, String>();
        HashMap hashMap = gson.fromJson(jsonStr, map.getClass());
        System.out.println(hashMap);
        System.out.println(hashMap.get("id"));

        //将json解析成java对象
        Student s = gson.fromJson(jsonStr, Student.class);
        System.out.println(s);

        //将java对象转化为json
        Student student = new Student("1222", "张三", 26, "男", "一班");
        String s1 = gson.toJson(student);
        System.out.println(s1);



//输出结果

{"id":"1500100001","name":"施笑槐","age":"22","gender":"女","clazz":"文科六班"}
{gender=女, name=施笑槐, id=1500100001, clazz=文科六班, age=22}
1500100001
Student(id=1500100001, name=施笑槐, age=22, gender=女, clazz=文科六班)
{"id":"1222","name":"张三","age":26,"gender":"男","clazz":"一班"}

    }
}

需要先导依赖

<!-- https://mvnrepository.com/artifact/com.google.code.gson/gson -->
<dependency>
    <groupId>com.google.code.gson</groupId>
    <artifactId>gson</artifactId>
    <version>2.8.5</version>
</dependency>


   <!-- https://mvnrepository.com/artifact/org.projectlombok/lombok -->
   <dependency>
       <groupId>org.projectlombok</groupId>
       <artifactId>lombok</artifactId>
       <version>1.18.20</version>
       <scope>provided</scope>
   </dependency>

 

public class Demo3 {
    public static void main(String[] args) {
        String jsonStr="{\"id\":\"1500100001\",\"name\":\"施笑槐\",\"age\":\"22\",\"gender\":\"女\",\"clazz\":\"文科六班\"}";
        JSONObject jsonObject = JSON.parseObject(jsonStr);
        Object id = jsonObject.get("id");
        System.out.println(id);

        Student student = JSON.parseObject(jsonStr, Student.class);
        int age = student.getAge();
        System.out.println(age);

//输出结果

1500100001
22

    }
}

 

依赖：

<!-- https://mvnrepository.com/artifact/junit/junit -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>