Lomkob引入

Lomkob引入项目中经常使用bean，entity等类，绝大部分数据类类中都需要get、set、toString、equals和hashCode方法，虽然eclipse和idea开发环境下都有自动生成的快捷方式，但自动生成这些代码后，如果bean中的属性一旦有修改、删除或增加时，需要重新生成或删除get/set等方法，给代码维护增加负担。而使用了lombok则不一样，使用了lombok的注解(@Setter,@Getter,@ToString,@@RequiredArgsConstructor,@EqualsAndHashCode或@Data)之后，就不需要编写或生成get/set等方法，很大程度上减少了代码量，而且减少了代码维护的负担。故强烈建议项目中使用lombok，去掉bean中get、set、toString、equals和hashCode等方法的代码。

 

<!--[if !supportLists]-->一、         <!--[endif]-->下载lombok

地址：https://projectlombok.org/

 

<!--[if !supportLists]-->二、       <!--[endif]-->将Lombok.jar 放在eclipse安装目录下（与eclipse.ini文件平级）

<!--[if !supportLists]-->三、         <!--[endif]-->运行lombok.jar

<!--[if !supportLists]-->a)       <!--[endif]-->运行后会弹框如下框，直接点确定

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<!--[if !supportLists]-->b)       <!--[endif]-->点specify location 按钮，选择eclipse的安装目录，选择到eclipse层即可

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<!--[if !supportLists]-->c)        <!--[endif]-->点击Install/update按钮

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<!--[if !supportLists]-->d)       <!--[endif]-->查看eclipse.ini文件，如果在文件末端添加了-javaagent:D:\soft\eclipse\lombok.jar那么恭喜你安装成功了

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D:\soft\eclipse\lombok.jar为lombok所在路径

<!--[if !supportLists]-->四、         <!--[endif]-->重启Eclipse

<!--[if !supportLists]-->五、         <!--[endif]-->编写实体类（以下提供常用实体类比较）

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等同于

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等同于

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等同于

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<!--[if !supportLists]-->六、         <!--[endif]-->Lombok常用注解解释

a)、@NonNull

这个注解可以用在成员方法或者构造方法的参数前面，会自动产生一个关于此参数的非空检查，如果参数为空，则抛出一个空指针异常。举个例子看一下

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等同于

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@Cleanup

用在变量前面，可以保证此变量代表的资源会被自动关闭，默认是调用资源的close()方法，如果该资源有其它关闭方法，可使用@Cleanup(“methodName”)来指定要调用的方法。使用输入输出流举个例子

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等同于

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@Getter

              用在变量前面，用于生成get方法，同时对相应方法进行修饰符配置

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等同于

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@Setter

用在变量前面，用于生成set方法，同时对相应方法进行修饰符配置

@ToString

用在类前面，用于生成toString方法

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等同于

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@EqualsAndHashCode

用于类前面，生成类的equals以及hashCode方法

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等同于

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@NoArgsConstructor

参考五、编写实体类（以下提供常用实体类比较）

@AllArgsConstructor

参考五、编写实体类（以下提供常用实体类比较）

@Data

参考五、编写实体类（以下提供常用实体类比较）

@SneakyThrows

用在方法上，可以将方法中的代码用try-catch语句包裹起来，捕获异常并在catch中用Lombok.sneakyThrow(e)把异常抛出，可以使用@SneakyThrows(Exception.class)的形式指定抛出哪种异常

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等同于

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@Synchronized

用在类方法或者实例方法上，效果和synchronized关键字相同

@Log

用在类上，可以省去从日志工厂生成日志对象这一步，直接进行日志记录，具体注解根据日志工具的不同而不同，同时，可以在注解中使用topic来指定生成log对象时的类名。

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等同于

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由于日志工具的不同，所等价的代码也不尽相同，一下列举常用日志工具的对比

@CommonsLog =

privatestaticfinal org.apache.commons.logging.Log log = org.apache.commons.logging.LogFactory.getLog(LogExample.class);

@JBossLog =

privatestaticfinal org.jboss.logging.Logger log = org.jboss.logging.Logger.getLogger(LogExample.class);

@Log =

privatestaticfinal java.util.logging.Logger log = java.util.logging.Logger.getLogger(LogExample.class.getName());

@Log4j =

privatestaticfinal org.apache.log4j.Logger log = org.apache.log4j.Logger.getLogger(LogExample.class);

@Log4j2 =

privatestaticfinal org.apache.logging.log4j.Logger log = org.apache.logging.log4j.LogManager.getLogger(LogExample.class);

@Slf4j =

privatestaticfinal org.slf4j.Logger log = org.slf4j.LoggerFactory.getLogger(LogExample.class);

@XSlf4j =

privatestaticfinal org.slf4j.ext.XLogger log = org.slf4j.ext.XLoggerFactory.getXLogger(LogExample.class);