lombok可以为我们减少样板代码,也可以让我们更早的体验Java的未来特性。
官网: https://projectlombok.org/
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.
这个注解,可以让我们不用写set、get、hashCode、toString方法。
项目结构:
├── build.gradle ├── settings.gradle └── src ├── main │ ├── java │ │ └── demo │ │ ├── Main.java │ │ └── Person.java │ └── resources └── test ├── java └── resources
build.gradle:
plugins { id 'java' } group 'com.example' version '1.0-SNAPSHOT' sourceCompatibility = 1.8 repositories { mavenCentral() } dependencies { compile group: 'org.projectlombok', name: 'lombok', version: '1.18.0' testCompile group: 'junit', name: 'junit', version: '4.12' }
虽然是compile,但lombok只是在编译期使用。
package demo; import lombok.AllArgsConstructor; import lombok.Data; import java.io.Serializable; @Data @AllArgsConstructor public class Person implements Serializable { private String name; private int age; }
package demo; public class Main { public static void main(String[] args) { Person p = new Person("Tom", 18); System.out.println(p); System.out.println(p.getName()); System.out.println(p.getAge()); } }
编译运行:
$ gradle build $ java -classpath build/libs/demo-1.0-SNAPSHOT.jar demo.Main Person(name=Tom, age=18) Tom 18
用Intellij IDEA编辑、运行代码,需要装lombok插件,以及做一些配置。可以参考《 IDEA下lombok安装,以及找不到get,set的问题 》。
Slf4j是一个日志框架。
项目结构:
├── build.gradle ├── settings.gradle └── src ├── main │ ├── java │ │ └── demo │ │ └── Main.java │ └── resources └── test ├── java └── resources
build.gradle :
plugins { id 'java' } group 'com.example' version '1.0-SNAPSHOT' sourceCompatibility = 1.8 repositories { mavenCentral() } dependencies { compile group: 'org.projectlombok', name: 'lombok', version: '1.18.0' compile group: 'org.slf4j', name: 'slf4j-api', version: '1.7.25' compile group: 'org.slf4j', name: 'slf4j-simple', version: '1.7.25' testCompile group: 'junit', name: 'junit', version: '4.12' }
@Slf4j 可以自动生成 log 变量。
package demo; import lombok.extern.slf4j.Slf4j; @Slf4j public class Main { public static void main(String[] args) { log.info("1+1 = {}", 2); } }
运行 Main
类,输出:
[main] INFO demo.Main - 1+1 = 2