Lombok是什么?它是一个能帮我们消除那些必须要写但是重复的代码,比如setter,getter,构造函数之类的方法。
首先先简单说一下idea安装lombok,有2种方法:
1.直接从http://plugins.jetbrains.com/下载,然后放到idea安装文件下面的plugins,然后重启idea
2.在idea的settings(windows)或者Preferences(mac),下找到plugins菜单,点击Browse repositories,如图
然后搜索lombok,点击右侧下载,下载完成重启即可,如图
新建项目,在pom文件中加入lombok依赖,完整pom如下:
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.dalaoyang</groupId> <artifactId>springboot_lombok</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>springboot_lombok</name> <description>springboot_lombok</description> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.5.9.RELEASE</version> <relativePath/> <!-- lookup parent from repository --> </parent> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <java.version>1.8</java.version> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-devtools</artifactId> <scope>runtime</scope> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <version>1.16.20</version> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project>
新建一个User类,这个是使用lombok的类,代码如下:
package com.dalaoyang.entity; import lombok.AllArgsConstructor; import lombok.Data; import lombok.NoArgsConstructor; /** * @author dalaoyang * @Description * @project springboot_learn * @package com.dalaoyang * @email yangyang@dalaoyang.cn * @date 2018/5/7 */ @Data @AllArgsConstructor @NoArgsConstructor public class User { private Integer id; private String name; private String password; }
新建一个UserNoLombok类,这个和原来一样,目的为了对比使用lombok的好处,代码如下:
package com.dalaoyang.entity; import java.util.Objects; /** * @author dalaoyang * @Description * @project springboot_learn * @package com.dalaoyang.entity * @email yangyang@dalaoyang.cn * @date 2018/5/7 */ public class UserNoLombok { private Integer id; private String name; private String password; 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 String getPassword() { return password; } public void setPassword(String password) { this.password = password; } public UserNoLombok(Integer id, String name, String password) { this.id = id; this.name = name; this.password = password; } public UserNoLombok() { } @Override public boolean equals(Object o) { if (this == o) return true; if (o == null || getClass() != o.getClass()) return false; UserNoLombok that = (UserNoLombok) o; return Objects.equals(id, that.id) && Objects.equals(name, that.name) && Objects.equals(password, that.password); } @Override public int hashCode() { return Objects.hash(id, name, password); } @Override public String toString() { return "UserNoLombok{" + "id=" + id + ", name='" + name + '\'' + ", password='" + password + '\'' + '}'; } }
然后新建一个UserController测试,代码如下:
package com.dalaoyang.controller;
import com.dalaoyang.entity.User;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
/**
* @author dalaoyang
* @Description
* @project springboot_learn
* @package com.dalaoyang.controller
* @email yangyang@dalaoyang.cn
* @date 2018/5/7
*/
@RestController
public class UserController {
@GetMapping("/testUser")
public User getUser(){
User user = new User();
user.setId(1);
user.setName("dalaoyang");
user.setPassword("123");
System.out.println(user.toString());
return user;
}
}
访问http://localhost:8080/testUser如图
lombok注解简介:
@Data 标签,生成getter/setter toString()等方法 @NonNull : 让你不在担忧并且爱上NullPointerException @CleanUp : 自动资源管理:不用再在finally中添加资源的close方法 @Setter/@Getter : 自动生成set和get方法 @ToString : 自动生成toString方法 @EqualsAndHashcode : 从对象的字段中生成hashCode和equals的实现 @NoArgsConstructor/@RequiredArgsConstructor/@AllArgsConstructor 自动生成构造方法 @Data : 自动生成set/get方法,toString方法,equals方法,hashCode方法,不带参数的构造方法 @Value : 用于注解final类 @Builder : 产生复杂的构建器api类 @SneakyThrows : 异常处理(谨慎使用) @Synchronized : 同步方法安全的转化 @Getter(lazy=true) : @Log : 支持各种logger对象,使用时用对应的注解,如:@Log4j
源码下载 :大老杨码云