Json工具类的使用

学习目标：

掌握两种Json工具类的使用

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学习内容：

1.Json对象的创建和设定

2.Json对象转字符串

3.Json字符串转实体类

4.字符串转Json对象

5.Json字符串转Json数组

6.Json数组转实体类集合

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学习时间：

• 周一至周五晚上 7 点—晚上9点

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学习产出：

1.使用hutool

1.1.导入依赖

    
        cn.hutool
        hutool-all
        4.1.14
    

1.2.测试代码

public class testHutool {
    public static void main(String[] args) {
        JSONObject obj = JSONUtil.createObj();
        obj.put("id", 1);
        obj.put("name", "林");
        obj.put("address", "山东");
        obj.put("sex","男");
        System.out.println(obj);
        String s = JSONUtil.toJsonStr(obj);
        System.out.println(s);
        Student student = JSONUtil.toBean(s, Student.class);
        System.out.println(student);
        JSONObject jsonObject = JSONUtil.parseObj(s);
        System.out.println(jsonObject);
        List stuList = new ArrayList<>();
        for (int i = 1; i < 5; i++) {
            Student stu = new Student();
            stu.setId(i);
            stu.setAddress("山东" + i);
            stu.setName("林" + i);
            stuList.add(stu);
        }
        String s1 = JSONUtil.toJsonStr(stuList);
        System.out.println(s1);
        JSONArray objects = JSONUtil.parseArray(stuList);
        List students = JSONUtil.toList(objects, Student.class);
        System.out.println(students);
    }
}

1.3.测试结果

{"address":"山东","sex":"男","name":"林","id":1}
{"address":"山东","sex":"男","name":"林","id":1}
Student{id=1, name='林', address='山东'}
{"address":"山东","sex":"男","name":"林","id":1}
[{"address":"山东1","name":"林1","id":1},{"address":"山东2","name":"林2","id":2},{"address":"山东3","name":"林3","id":3},{"address":"山东4","name":"林4","id":4}]
[Student{id=1, name='林1', address='山东1'}, Student{id=2, name='林2', address='山东2'}, Student{id=3, name='林3', address='山东3'}, Student{id=4, name='林4', address='山东4'}]

2.使用fastjson

2.1导入依赖

    
        com.alibaba
        fastjson
        1.2.28
    

2.2测试代码

public class testFastjson {
    public static void main(String[] args) {
        JSONObject jsonData = new JSONObject();
        jsonData.put("id", 1);
        jsonData.put("name", "林");
        jsonData.put("address", "山东");
        System.out.println("-------" + jsonData);
        String jsonString = JSON.toJSONString(jsonData);
        System.out.println("*******" + jsonString);
        JSONObject jsonObject = JSON.parseObject(jsonString);
        System.out.println("///" + jsonObject.getString("name"));
        Student student = JSON.parseObject(jsonString, Student.class);
        System.out.println("|||||||" + student.toString());
        List stuList = new ArrayList<>();
        for (int i = 1; i < 5; i++) {
            Student stu = new Student();
            stu.setId(i);
            stu.setAddress("山东" + i);
            stu.setName("林" + i);
            stuList.add(stu);
        }
        String s = JSON.toJSONString(stuList);
        System.out.println(s);
        JSONArray objects = JSON.parseArray(JSON.toJSONString(stuList));
        System.out.println(objects.stream().iterator().next());
        List students = JSON.parseArray(JSON.toJSONString(stuList), Student.class);
        System.out.println(students);
    }

2.3测试结果

-------{"address":"山东","name":"林","id":1}
*******{"address":"山东","name":"林","id":1}
///林
|||||||Student{id=1, name='林', address='山东'}
[{"address":"山东1","id":1,"name":"林1"},{"address":"山东2","id":2,"name":"林2"},{"address":"山东3","id":3,"name":"林3"},{"address":"山东4","id":4,"name":"林4"}]
{"address":"山东1","name":"林1","id":1}
[Student{id=1, name='林1', address='山东1'}, Student{id=2, name='林2', address='山东2'}, Student{id=3, name='林3', address='山东3'}, Student{id=4, name='林4', address='山东4'}]