一,引入jar
maven 项目中,只需要引入下面的dependency
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>1.7.2</version>
</dependency>
二、配置log4j.properties
因为log4j是具体的实现框架,需要配置log4j.properties
# rootLogger参数分别为:根Logger级别,输出器stdout,输出器log
log4j.rootLogger = info,stdout,log
# 输出信息到控制台
log4j.appender.stdout = org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout = org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern = %d [%-5p] %l %rms: %m%n
# 输出DEBUG级别以上的日志到D://logs/debug.log
log4j.appender.log = org.apache.log4j.DailyRollingFileAppender
log4j.appender.log.DatePattern = '.'yyyy-MM-dd
log4j.appender.log.File = D://debug.log
log4j.appender.log.Encoding = UTF-8
#log4j.appender.log.Threshold = INFO
log4j.appender.log.layout = org.apache.log4j.PatternLayout
log4j.appender.log.layout.ConversionPattern = %d [%-5p] (%c.%t): %m%n
三、初始化log4j环境
web环境中,启动容器时候,就初始化log4j,在web.xml中配置如下:
<!-- 配置log4j配置文件路径 -->
<context-param>
<param-name>log4jConfigLocation</param-name>
<param-value>classpath:conf/log4j.properties</param-value>
</context-param>
<!-- 60s 检测日志配置 文件变化 -->
<context-param>
<param-name>log4jRefreshInterval</param-name>
<param-value>60000</param-value>
</context-param>
<!-- 配置Log4j监听器 -->
<listener>
<listener-class>org.springframework.web.util.Log4jConfigListener</listener-class>
</listener>
四、使用
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class Main {
private static final Logger logger = LoggerFactory.getLogger(Main.class);
public static void main(String[] args) {
int status = 0;
if (status == 0) {
logger.info("status:{}", status);
} else {
logger.info("status:{}", status);
}
logger.info("end!");
}
}
五、总结
如果需要更换项目的SLF4J日志框架实现,比如logback,不需要修改代码,直接更换日志框架的实现,很方便。