Log4j:

添加依赖：

  1.          <!-- 整合Log4j-->
  2.         <dependency>
  3.             <groupId>log4j</groupId>
  4.             <artifactId>log4j</artifactId>
  5.             <version>1.2.17</version>
  6.         </dependency>
  7.         <dependency>
  8.             <groupId>org.slf4j</groupId>
  9.             <artifactId>slf4j-api</artifactId>
  10.             <version>1.7.25</version>
  11.         </dependency>
  12.         <dependency>
  13.             <groupId>org.slf4j</groupId>
  14.             <artifactId>slf4j-log4j12</artifactId>
  15.             <version>1.7.25</version>
  16.             <scope>test</scope>
  17.         </dependency>
  18.         <dependency>
  19.             <groupId>org.slf4j</groupId>
  20.             <artifactId>slf4j-simple</artifactId>
  21.             <version>1.7.25</version>
  22.             <scope>test</scope>
  23.         </dependency>

创建配置文件：

  1. log4j.rootLogger=DEBUG, stdout
  2. log4j.appender.stdout=org.apache.log4j.ConsoleAppender
  3. log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
  4. log4j.appender.stdout.layout.ConversionPattern=[%p] [%C]{1} - %m%n

运行任意NIO服务即可查看Log4j配置生效情况
image.png
Log4j配置已生效

添加日志：

在handler中添加Netty内置的 LoggingHandler 即可，参考心跳检测和WebSocket章节