Lombok 之 Log

LomBok 的相关目录已经整理出来，希望大家可以根据需求自助学习，好工具要大家分享：

@Cleanup     

@Getter, @Setter

@ToString

@EqualsAndHashCode

@Constructor

@Data & @Value

@SneakyThrows

@Synchronized

@Getter(lazy=true)

@Log

这是本系列最后一个annotation了，也是Lombok里面最好用的一个了，我们每天写项目都会有很多日志需要记录，很多人都写过这样的代码：

private static final org.apache.commons.logging.Log log = org.apache.commons.logging.LogFactory.getLog(LogExample.class);

Lombok的方便不是说说而已的，哪里有重复，哪里就有Lombok（YY的 :) ），Lombok封装了许多主流的Log库，提供了一系列关于Log 的annotation。下面就是所有的annotation会代表哪些特定的类 :

@CommonsLog
Creates private static final org.apache.commons.logging.Log log = org.apache.commons.logging.LogFactory.getLog(LogExample.class);
@Log
Creates private static final java.util.logging.Logger log = java.util.logging.Logger.getLogger(LogExample.class.getName());
@Log4j
Creates private static final org.apache.log4j.Logger log = org.apache.log4j.Logger.getLogger(LogExample.class);
@Log4j2
Creates private static final org.apache.logging.log4j.Logger log = org.apache.logging.log4j.LogManager.getLogger(LogExample.class);
@Slf4j
Creates private static final org.slf4j.Logger log = org.slf4j.LoggerFactory.getLogger(LogExample.class);
@XSlf4j
Creates private static final org.slf4j.ext.XLogger log = org.slf4j.ext.XLoggerFactory.getXLogger(LogExample.class);

就用其中的几个举个例子吧：

import lombok.extern.java.Log;
 import lombok.extern.slf4j.Slf4j;
 
 @Log
 public class LogExample {
   
   public static void main(String... args) {
     log.error("Something's wrong here");
   }
 }
 
 @Slf4j
 public class LogExampleOther {
   
   public static void main(String... args) {
     log.error("Something else is wrong here");
   }
 }
 
 @CommonsLog(topic="CounterLog")
 public class LogExampleCategory {
 
   public static void main(String... args) {
     log.error("Calling the 'CounterLog' with a message");
   }
 }

翻译一下，代码如下：

public class LogExample {
  private static final java.util.logging.Logger log = java.util.logging.Logger.getLogger(LogExample.class.getName());
  
  public static void main(String... args) {
    log.error("Something's wrong here");
  }
}

public class LogExampleOther {
  private static final org.slf4j.Logger log = org.slf4j.LoggerFactory.getLogger(LogExampleOther.class);
  
  public static void main(String... args) {
    log.error("Something else is wrong here");
  }
}

public class LogExampleCategory {
  private static final org.apache.commons.logging.Log log = org.apache.commons.logging.LogFactory.getLog("CounterLog");

  public static void main(String... args) {
    log.error("Calling the 'CounterLog' with a message");
  }
}

想必不用多说了，例子一看就懂了，唠叨一句就是annotation提供一个topic选项，可以定制化getLog方法的参数。 为什么没提供backlog呢？ 一直用backlog啊