@slf4j注解找不到log變量

問題描述：使用了@Slf4j注解但是沒有找到log對象。

　　

 

解決辦法：

　　eclipse安裝lombok.jar。

• 1.下載lombok.jar包https://projectlombok.org/download.html

• 2.運行Lombok.jar: Java -jar D:\software\lombok.jar D:\software\lombok.jar這是windows下lombok.jar所在的位置

    數秒后將彈出一框，以確認eclipse的安裝路徑</code>

• 3.確認完eclipse的安裝路徑后，點擊install/update按鈕，即可安裝完成

• 4.安裝完成之后，請確認eclipse安裝路徑下是否多了一個lombok.jar包，並且其

  配置文件eclipse.ini中是否 添加了如下內容: </code>

      -javaagent:lombok.jar 
      -Xbootclasspath/a:lombok.jar 

  那么恭喜你已經安裝成功，否則將缺少的部分添加到相應的位置即可 </code>

• 5.重啟eclipse或myeclipse

 日志注解的解釋和用法說明：

Overview

You put the variant of @Log on your class (whichever one applies to the logging system you use); you then have a static final log field, initialized to the name of your class, which you can then use to write log statements.

There are several choices available:

@CommonsLog

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

@JBossLog

Creates  private static final org.jboss.logging.Logger log = org.jboss.logging.Logger.getLogger(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);

 

By default, the topic (or name) of the logger will be the class name of the class annotated with the @Log annotation. This can be customised by specifying the topic parameter. For example: @XSlf4j(topic="reporting").

With Lombok

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");
  }
}

 

Vanilla Java

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");
  }
}

Supported configuration keys:

lombok.log.fieldName =  an identifier (default:  log).

The generated logger fieldname is by default ' log', but you can change it to a different name with this setting.

lombok.log.fieldIsStatic = [ true |  false] (default: true)

Normally the generated logger is a  static field. By setting this key to  false, the generated field will be an instance field instead.

lombok.log.flagUsage = [ warning |  error] (default: not set)

Lombok will flag any usage of any of the various log annotations as a warning or error if configured.

lombok.log.apacheCommons.flagUsage = [ warning |  error] (default: not set)

Lombok will flag any usage of  @lombok.extern.apachecommons.CommonsLog as a warning or error if configured.

lombok.log.javaUtilLogging.flagUsage = [ warning |  error] (default: not set)

Lombok will flag any usage of  @lombok.extern.java.Log as a warning or error if configured.

lombok.log.jbosslog.flagUsage = [ warning |  error] (default: not set)

Lombok will flag any usage of  @lombok.extern.jbosslog.JBossLog as a warning or error if configured.

lombok.log.log4j.flagUsage = [ warning |  error] (default: not set)

Lombok will flag any usage of  @lombok.extern.log4j.Log4j as a warning or error if configured.

lombok.log.log4j2.flagUsage = [ warning |  error] (default: not set)

Lombok will flag any usage of  @lombok.extern.log4j.Log4j2 as a warning or error if configured.

lombok.log.slf4j.flagUsage = [ warning |  error] (default: not set)

Lombok will flag any usage of  @lombok.extern.slf4j.Slf4j as a warning or error if configured.

lombok.log.xslf4j.flagUsage = [ warning |  error] (default: not set)

Lombok will flag any usage of  @lombok.extern.slf4j.XSlf4j as a warning or error if configured.