前言
这边文章描述怎么使用slf4j.
1.使用步骤
a.maven导入依赖
<!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-api --> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-api</artifactId> <version>1.7.5</version> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-log4j12</artifactId> <version>1.7.5</version> <!-- <scope>test</scope> --> </dependency>
b.在resources路径下添加配置文件 log4j.properties
### 设置### log4j.rootLogger=debug,stdout,D,E ### 输出信息到控制抬 ### log4j.appender.stdout=org.apache.log4j.ConsoleAppender log4j.appender.stdout.Target=System.out log4j.appender.stdout.layout=org.apache.log4j.PatternLayout log4j.appender.stdout.layout.ConversionPattern=[%-5p] %d{yyyy-MM-dd HH:mm:ss,SSS} method:%l%n%m%n ### 输出DEBUG 级别以上的日志到=E://logs/error.log ### log4j.appender.D=org.apache.log4j.DailyRollingFileAppender log4j.appender.D.File=D://logs/log.log log4j.appender.D.Append=true log4j.appender.D.Threshold=DEBUG log4j.appender.D.layout=org.apache.log4j.PatternLayout log4j.appender.D.layout.ConversionPattern=%-d{yyyy-MM-dd HH:mm:ss} [ %t:%r ] - [ %p ] %m%n ### 输出ERROR 级别以上的日志到=E://logs/error.log ### log4j.appender.E=org.apache.log4j.DailyRollingFileAppender log4j.appender.E.File=D://logs/error.log log4j.appender.E.Append=true log4j.appender.E.Threshold=ERROR log4j.appender.E.layout=org.apache.log4j.PatternLayout log4j.appender.E.layout.ConversionPattern=%-d{yyyy-MM-dd HH:mm:ss} [ %t:%r ] - [ %p ] %m%n
c.添加java代码
public class Log4jTestDemo { private static Logger logger = LoggerFactory.getLogger(Log4jTestDemo.class); public static void main(String[] args) { System.out.println("This is println message."); // 记录debug级别的信息 logger.debug("This is debug message."); // 记录info级别的信息 logger.info("This is info message."); // 记录error级别的信息 logger.error("This is error message."); } }
2.常见的问题
a.提示下面错误
SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
原因是因为导入maven时没有导入
<dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-log4j12</artifactId> <version>1.7.5</version> <!-- <scope>test</scope> --> </dependency>
来源:https://www.cnblogs.com/jianpanaq/p/10274648.html