slf4j中如何进行log4j配置呢?

步骤一:pom.xml添加log4j依赖

<dependency>
	<groupId>org.slf4j</groupId>
	<artifactId>slf4j-api</artifactId>
	<version>1.7.25</version>
</dependency>
<dependency>
	<groupId>log4j</groupId>
	<artifactId>log4j</artifactId>
	<version>1.2.17</version>
</dependency>
<dependency>
	<groupId>org.slf4j</groupId>
	<artifactId>slf4j-log4j12</artifactId>
	<version>1.7.25</version>
</dependency>
或者
<dependency>
  <groupId>org.slf4j</groupId>
  <artifactId>slf4j-log4j12</artifactId>
  <version>1.8.0-alpha2</version>
</dependency>

步骤二：配置log4j

测试代码

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class LoggerTest {
    private static final Logger logger = LoggerFactory.getLogger(LoggerTest.class);

    public static void main(String[] args) {
        logger.fatal("致命错误");
	    logger.error("严重警告");
	    logger.info("普通信息");
	    logger.debug("调试信息");
    }
}

注意事项:
   这里要用SLF4J来写记录日志的代码
   而不能用log4j去写日志
 当需要切换其他的日志框架如logback只需要更改依赖即可