FastJson的学习之JSON互相转Map集合，List集合，JavaBean

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

创建两个实体类 一个是部门类，一个是部门员工类

部门员工类

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 +
                '}';
    }
 }

部门类

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 +
                '}';
    }
}

对象转为json字符串格式

JSON.toJSONString(Object object)

@Test
    public void fun1(){
        List<Person> personArrayList = new ArrayList<Person>();
        Person person = new Person();
        person.setId();
        person.setName("张三");
        person.setAge();
        System.out.println(JSON.toJSONString(person));
        personArrayList.add(person);
        Person person1 = new Person();
        person1.setId();
        person1.setName("李四");
        person1.setAge();
        personArrayList.add(person1);
        System.out.println(JSON.toJSONString(person1));
        Dept dept = new Dept();
        dept.setDeptName("财务部");
        dept.setPersonList(personArrayList);
        String jsonString = JSON.toJSONString(personArrayList);
        System.out.println(jsonString);
    }

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JSON字符串转JavaBean

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

@Test
    public void fun2(){
        String str1="{\"age\":18,\"id\":1,\"name\":\"张三\"}";
        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));
 
    }

控制台打印

JSON字符串数组转List集合

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

 @Test
    public void fun3(){
        String str="[{\"age\":18,\"id\":1,\"name\":\"张三\"},{\"age\":18,\"id\":2,\"name\":\"李四\"}]";
        List<Person> PersonList=JSON.parseArray(str,Person.class);
        System.out.println(PersonList);
    }

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Map集合转json

JSON.toJSONString(Object object)

@Test
    public void fun4(){
        Map<String,Person> personMap=new HashMap<String, Person>();
        Person person = new Person();
        person.setId();
        person.setName("张三");
        person.setAge();
        personMap.put("zhangsan",person);
 
        Person person1 = new Person();
        person1.setId();
        person1.setName("李四");
        person1.setAge();
        personMap.put("lisi",person1);
 
        String json =  JSON.toJSONString(personMap);
        System.out.println(json);
    }

控制台打印的信息

MapJson字符串转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\":\"张三\"}}";
        Map<String,Person> map = (Map)JSONObject.parse(str);
        System.out.println(map.get("lisi"));
        System.out.println(map.get("zhangsan"));
    }

控制台的打印输出