Lombok(1.14.8)

@Getter / @Setter

@Getter 和 @Setter，分别实现了 Gette r和 Setter 方法。

package com.huey.hello.bean;

import java.util.Date;

import lombok.Getter;
import lombok.Setter;

public class Student {

    @Getter @Setter
    private int studNo;
    @Getter @Setter
    private String studName;
    @Getter @Setter
    private Date birthday;

    public static void main(String[] args) {
        Student stud = new Student();
        stud.setStudName("huey");
        System.out.println(stud.getStudName());    // [OUTPUT]: huey
    }
}

@ToString

@ToString，实现了 toString() 方法。

package com.huey.hello.bean;

import java.util.Date;

import lombok.Getter;
import lombok.Setter;
import lombok.ToString;

@ToString
public class Student {

    @Getter @Setter
    private int studNo;
    @Getter @Setter
    private String studName;
    @Getter @Setter
    private Date birthday;

    public static void main(String[] args) {
        Student stud = new Student();
        stud.setStudNo(10001);
        stud.setStudName("huey");
        stud.setBirthday(new Date());
        System.out.println(stud);        // [OUTPUT]: Student(studNo=10001, studName=huey, birthday=Fri Jul 31 23:01:56 CST 2015)
    }
}

@EqualsAndHashCode

@EqualsAndHashCode，实现了 equals() 和 hashCode() 方法。

package com.huey.hello.bean;

import java.util.Date;

import lombok.EqualsAndHashCode;
import lombok.Getter;
import lombok.Setter;

@EqualsAndHashCode
public class Student {

    @Getter @Setter
    private int studNo;
    @Getter @Setter
    private String studName;
    @Getter @Setter
    private Date birthday;

    public static void main(String[] args) {
        Student stud1 = new Student();
        stud1.setStudNo(10001);
        stud1.setStudName("huey");
        stud1.setBirthday(new Date());

        Student stud2 = new Student();
        stud2.setStudNo(10001);
        stud2.setStudName("huey");
        stud2.setBirthday(new Date());

        System.out.println(stud1.hashCode());        // [OUTPUT]: -349449895
        System.out.println(stud2.hashCode());        // [OUTPUT]: -349449895
        System.out.println(stud1.equals(stud2));     // [OUTPUT]: true
    }
}

@Data

@Data，相当上述三个 annotation 以及 @RequiredArgsConstructor。

package com.huey.hello.bean;

import java.util.Date;

import lombok.Data;

@Data
public class Student {

    private int studNo;
    private String studName;
    private Date birthday;

    public static void main(String[] args) {
        Student stud1 = new Student();
        stud1.setStudNo(10001);
        stud1.setStudName("huey");
        stud1.setBirthday(new Date());

        Student stud2 = new Student();
        stud2.setStudNo(10001);
        stud2.setStudName("huey");
        stud2.setBirthday(new Date());

        System.out.println(stud1.hashCode());        // [OUTPUT]: -349006373
        System.out.println(stud2.hashCode());        // [OUTPUT]: -349006373
        System.out.println(stud1.equals(stud2));     // [OUTPUT]: true
        System.out.println(stud1);                   // [OUTPUT]: Student(studNo=10001, studName=huey, birthday=Fri Jul 31 23:13:43 CST 2015)
    }
}