[大数据]Json数据和实体类之间转换

Json数据和实体类之间转换

1.json->java

2.java->json

3.bean数组->Json数组

4.json数组->bean集合

1.实体类

package bean;
//实体类
public class User {
    private Integer id;
    private String name;
    private Integer age;

    public User() {
    }

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

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

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    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;
    }
}

2.转换过程

package test;

import bean.User;
import net.sf.json.JSONArray;
import net.sf.json.JSONObject;

import java.util.ArrayList;
import java.util.List;

public class Demo {
    public static void main(String[] args) {
        //java->json
        User user = new User(1,"范一伟",18);
        JSONObject jsonObject = JSONObject.fromObject(user);
        System.out.println(jsonObject);

        System.out.println("===============");
        //json->java
        String str1 = "{\"age\":18,\"id\":1,\"name\":\"范一伟\"}";
        JSONObject jsonObject1 = JSONObject.fromObject(str1);
        Object o = JSONObject.toBean(jsonObject1,User.class);
        System.out.println(o);

        System.out.println("===================");

        //ArrayList->json数组
        List users = new ArrayList();
        users.add(new User(1,"范一伟1",18));
        users.add(new User(2,"范一伟2",18));
        users.add(new User(3,"范一伟3",18));
        JSONArray jsonArray = JSONArray.fromObject(users);
        System.out.println(jsonArray);

        System.out.println("====================");
        //json数组->数组
        String str2 = "[{\"age\":18,\"id\":1,\"name\":\"范一伟1\"},{\"age\":18,\"id\":2,\"name\":\"范一伟2\"},{\"age\":18,\"id\":3,\"name\":\"范一伟3\"}]";
        JSONArray jsonArray1 = JSONArray.fromObject(str2);
        Object[] o1 = (Object[]) JSONArray.toArray(jsonArray, User.class);
        for (Object o2 : o1) {
            System.out.println(o2);
        }

    }
}

3.相关jar包

ss);
for (Object o2 : o1) {
System.out.println(o2);
}

}

}

## 3.相关jar包
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