Lombok介绍

xubb 2018-03-01 原文

Lombok介绍

为什么要使用

减少冗余代码, 提升逼格.

安装IDEA插件

File -> Settings -> Plugins 搜索Lombok进行安装. 如遇到网络问题导致不能在线安装的, 通过http://plugins.jetbrains.com/plugin/6317-lombok-plugin 下载离线安装包, 点下图”Install plugin from disk…”进行安装

加入Lombok依赖

<dependency>
   <groupId>org.projectlombok</groupId>
   <artifactId>lombok</artifactId>
   <version>1.16.18</version>
   <scope>provided</scope>
</dependency>

Lombok在编译完后, 就没他事了, 所以Scope可以设置成provided,
这样打出来的包将不会包含lombok.jar

使用Lombok

@Getter, @Setter

可以标记类, 给所有非静态成员生成get/set方法. 下面两种写法效果等同:

正常写法

Lombok写法

class
User {

private String userId;

private String username;

public String getUserId() {

return userId;

}

public void setUserId(String userId) {

this.userId = userId;

}

public String getUsername() {

return username;

}

public void setUsername(String username)
{

this.username = username;

}

class
User {

@lombok.Getter

@lombok.Setter

private String userId;

@lombok.Getter

@lombok.Setter

private String username;

}

@ToString

生成toString方法, 默认将所有字段输出, 可以使用用exclude/of指定排除字段或包含字段

@EqualsAndHashCode

自动重写hashCode和equals方法. 同@ToString, 可以指定字段

@Slf4j

生成一个slf4j的log变量

正常写法

class
User {

private static final Logger log =
LoggerFactory.getLogger(User.class);

}

Lombok写法

@Slf4j

class
User {

}

完整比较

Lombok写法

@lombok.NoArgsConstructor

@lombok.AllArgsConstructor

@lombok.EqualsAndHashCode(of = "name")

@lombok.ToString(exclude = "password")

@lombok.extern.slf4j.Slf4j

  public class LombokDemo {


    @lombok.Getter

    @lombok.Setter

    private String name;


    @lombok.Getter

    @lombok.Setter

    private String password;


  }

正常写法

public class LombokDemo {


    private static final Logger log = LoggerFactory.getLogger(LombokDemo.class);


    private String name;


    private String password;


    public LombokDemo() {}


    public LombokDemo(String name, String password) {

        this.name = name;

        this.password = password;

    }


    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;

    }


    @Override

    public boolean equals(Object o) {

        if (this == o) return true;

        if (o == null || getClass() != o.getClass()) return false;


        LombokDemo that = (LombokDemo) o;


        return name != null ? name.equals(that.name) : that.name == null;

    }


    @Override

    public int hashCode() {

        return name != null ? name.hashCode() : 0;

    }


    @Override

    public String toString() {

        return "LombokDemo{" +

                "name='" + name + '\'' +

                '}';

    }

}