https://blog.csdn.net/weixin_36910300/article/details/79182120

建立兩個實體類 一個是部門類，一個是部門員工類

部門員工類

public class Person {

    private Integer id;

    private String name;

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

部門類

public class Dept {
    private String deptName;
    private List<Person> personList;

    public String getDeptName() {
        
 
return deptName;
    }

    public void setDeptName(String deptName) {
        this.deptName = deptName;
    }

    public List<Person> getPersonList() {
        return personList;
    }

    public void setPersonList(List<Person> personList) {
        this.personList = personList;
    }
    @Override
    public String toString() {
        return "Dept{" +
                "deptName='" + deptName + '\'' +
                ", personList=" + personList +
                '}';
    }
}

物件轉為json字串格式

JSON.toJSONString(Object object)

@Test
    public void fun1(){
        List<Person> personArrayList = new ArrayList<Person>();
        Person person = new Person();
        person.setId(1);
        person.setName("張三");
        person.setAge(18);
        System.out.println(JSON.toJSONString(person));
        personArrayList.add(person);
        Person person1 = new Person();
        person1.setId(2);
        person1.setName("李四");
        person1.setAge(18);
        personArrayList.add(person1);
        System.out.println(JSON.toJSONString(person1));
        Dept dept = new Dept();
        dept.setDeptName("財務部");
        dept.setPersonList(personArrayList);
        String jsonString = JSON.toJSONString(personArrayList);
        System.out.println(jsonString);
    }

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 JSON字串轉JavaBean

JSON.parseObject(String text,Class<T> clazz)

@Test
    public void fun2(){
        String str1="{\"age\":18,\"id\":1,\"name\":\"張三\"}";
        System.out.println(JSON.parseObject(str1,Person.class));
        String str2="{\"age\":18,\"id\":2,\"name\":\"李四\"}";
        System.out.println(JSON.parseObject(str2,Person.class));

    }

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JSON字串陣列轉List集合

JSON.parseArray(String text, Class<T> clazz)

 @Test
    public void fun3(){
        String str="[{\"age\":18,\"id\":1,\"name\":\"張三\"},{\"age\":18,\"id\":2,\"name\":\"李四\"}]";
        List<Person> PersonList=JSON.parseArray(str,Person.class);
        System.out.println(PersonList);
    }

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Map集合轉json

JSON.toJSONString(Object object)

@Test
    public void fun4(){
        Map<String,Person> personMap=new HashMap<String, Person>();
        Person person = new Person();
        person.setId(1);
        person.setName("張三");
        person.setAge(18);
        personMap.put("zhangsan",person);

        Person person1 = new Person();
        person1.setId(2);
        person1.setName("李四");
        person1.setAge(18);
        personMap.put("lisi",person1);

        String json =  JSON.toJSONString(personMap);
        System.out.println(json);
    }

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MapJson字串轉Map集合

(Map)JSON.parse(Object object)

@Test
    public void fun5(){
        String str="{\"lisi\":{\"age\":18,\"id\":2,\"name\":\"李四\"},\"zhangsan\":{\"age\":18,\"id\":1,\"name\":\"張三\"}}";
        Map<String,Person> map = (Map)JSONObject.parse(str);
        System.out.println(map.get("lisi"));
        System.out.println(map.get("zhangsan"));
    }

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