Json工具类的使用

快来打我* 2024-04-01 14:52 58阅读 0赞

## 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

--------------------

## 学习产出： ##

#### 1.使用hutool ####

1.1.导入依赖

<dependency>
            <groupId>cn.hutool</groupId>
            <artifactId>hutool-all</artifactId>
            <version>4.1.14</version>
        </dependency>

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<Student> 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<Student> 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

<dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.28</version>
        </dependency>

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<Student> 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<Student> 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'}]