FastJson初见

1.序列化

使用JSON.toJSONString()实现序列化。

1. 基本使用

public class User {
    private int age;
    private String userName;
    private Date birthDay;

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public Date getBirthDay() {
        return birthDay;
    }

    public void setBirthDay(Date birthDay) {
        this.birthDay = birthDay;
    }
}

public class FastJsonTestWithUser {
    public static void main(String[] args) {
        User user1 = new User();
        user1.setAge(23);
        user1.setUserName("Srammy");
        user1.setBirthDay(new Date());

        User user2 = new User();
        user2.setAge(23);
        user2.setUserName("Srammy");
        user2.setBirthDay(new Date());

        String jsonOutput1 = JSON.toJSONString(user2);
        System.out.println(jsonOutput1);

        List<User> userList = new ArrayList<User>();
        userList.add(user1);
        userList.add(user2);
        String jsonOutput2 = JSON.toJSONString(userList);
        System.out.println(jsonOutput2);
    }
}

输出

{
    "age": 23,
    "birthDay": 1602903665275,
    "userName": "Srammy"
}

[
    {
        "age": 23,
        "birthDay": 1602903665275,
        "userName": "Srammy"
    },
    {
        "age": 23,
        "birthDay": 1602903665275,
        "userName": "Srammy"
    }
]

2.使用@JSONField注解进行配置

name：序列化后的key

ordinal：序列化时字段的顺序

serialize：是否序列化

deserialize：是否反序列化

format：格式化date

public class Person {
    @JSONField(name = "AGE", ordinal = 3)
    private int age;

    @JSONField(name = "USERNAME", serialize = false)
    private String userName;

    @JSONField(name = "PASSWORD", ordinal = 1)
    private String password;

    @JSONField(name = "BirthDAY", format = "dd/MM/yyyy", ordinal = 2)
    private Date birthDay;

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public Date getBirthDay() {
        return birthDay;
    }

    public void setBirthDay(Date birthDay) {
        this.birthDay = birthDay;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    @Override
    public String toString() {
        return "Person{" +
                "age=" + age +
                ", userName='" + userName + '\'' +
                ", password='" + password + '\'' +
                ", birthDay=" + birthDay +
                '}';
    }
}

public class FastJsonTestWithPerson {
    public static void main(String[] args) {
        Person person = new Person();
        person.setAge(30);
        person.setBirthDay(new Date());
        person.setUserName("Yahaha");
        person.setPassword("#$%@123");

        String jsonOutput1 = JSON.toJSONString(person);
        System.out.println(jsonOutput1);
    }
}

输出

{
    "PASSWORD": "#$%@123",
    "BirthDAY": "17/10/2020",
    "AGE": 30
}

2. 反序列化

使用JSON.parseObject()实现反序列化

public class Person {
    @JSONField(name = "AGE", ordinal = 3)
    private int age;

    @JSONField(name = "USERNAME", serialize = false)
    private String userName;

    @JSONField(name = "PASSWORD", ordinal = 1)
    private String password;

    @JSONField(name = "BirthDAY", format = "dd/MM/yyyy", ordinal = 2, deserialize = false)
    private Date birthDay;

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public Date getBirthDay() {
        return birthDay;
    }

    public void setBirthDay(Date birthDay) {
        this.birthDay = birthDay;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    @Override
    public String toString() {
        return "Person{" +
                "age=" + age +
                ", userName='" + userName + '\'' +
                ", password='" + password + '\'' +
                ", birthDay=" + birthDay +
                '}';
    }
}

public class FastJsonTestWithPerson {
    public static void main(String[] args) {
        deserialization.Person person = new Person();
        person.setAge(30);
        person.setBirthDay(new Date());
        person.setUserName("Yahaha");
        person.setPassword("#$%@123");

        // 转为json串
        String jsonOutput1 = JSON.toJSONString(person);
        System.out.println(jsonOutput1);

        // 转为Java对象
        Person newPerson = JSON.parseObject(jsonOutput1, deserialization.Person.class);
        System.out.println(newPerson);
    }
}

输出

{"PASSWORD":"#$%@123","BirthDAY":"17/10/2020","AGE":30}
Person{age=30, userName='null', password='#$%@123', birthDay=null}

userName没有序列化，birthDay没有反序列化