Lombok笔记

一、Lombok简介

Project Lombok is a java library that automatically plugs into your editor and build tools, spicing up your java.
Never write another getter or equals method again. Early access to future java features such as val, and much more.

官网：https://projectlombok.org/

github：https://github.com/rzwitserloot/lombok

二、Lombok @Data源码

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Target({ElementType.TYPE})
@Retention(RetentionPolicy.SOURCE)
public @interface Data {
    String staticConstructor() default "";
}

a. ElementType.TYPE：说明该注解只能被声明在一个类前。

b. RetentionPolicy.SOURCE : 注解只保留在源文件中　

三、Lombok常用注解介绍

a. @NonNull

b. @Cleanup - Automatic resource management: Call your close() methods safely with no hassle.

c. @Getter/@Setter - Never write public int getFoo() {return foo;} again

d. @ToString - No need to start a debugger to see your fields: Just let lombok generate a toString for you!

e. @EqualsAndHashCode - Equality made easy: Generates hashCode and equals implementations from the fields of your object..

f. @NoArgsConstructor, @RequiredArgsConstructor and @AllArgsConstructor - Constructors made to order: Generates constructors that take no arguments, one argument per final / non-nullfield, or one argument for every field.

g. @Data - All together now: A shortcut for @ToString, @EqualsAndHashCode, @Getter on all fields, and @Setter on all non-final fields, and @RequiredArgsConstructor!

h. @Synchronized - synchronized done right: Don't expose your locks.

四、举例

@Data
@NoArgsConstructor
@AllArgsConstructor
public class LombokForm {

    private String name;
    private int age;

}

public class LombokTest {

    @Test
    public void test() {

        String defaultName = "aaa";
        int defaultAge = 10;

        LombokForm lombokForm = new LombokForm(defaultName, defaultAge);
        String str = lombokForm.toString();

        String name = lombokForm.getName();
        int age = lombokForm.getAge();

        System.out.println(lombokForm.toString());
        Assert.assertEquals(defaultName, name);
        Assert.assertEquals(defaultAge, age);

    }
}

五、参考

a. https://www.jianshu.com/p/365ea41b3573

b. https://blog.csdn.net/cb905259982/article/details/73161948

c. https://projectlombok.org/