前言
至于slf4j和log4j还有其他日志工具的关系这里就不具体说明。 具体可参考如下： https://www.techug.com/post/how-log4j-designed.html
初识slf4j
创建Maven项目 这里使用IDEA工具： 其他参数默认即可。。。 添加依赖到pom.xml
<dependencies>
<!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-api -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.7.25</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-log4j12 -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>1.7.25</version>
<!--<scope>test</scope>-->
</dependency>
</dependencies>
添加资源log4j.properties 在 src/main/resources/ 下创建 log4j.properties，内容如下： 注意修改输出的路径
### 设置###
log4j.rootLogger = debug,stdout,D,E,I
### 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://project//LoggerTest//target//log//debug.log ###
log4j.appender.D = org.apache.log4j.DailyRollingFileAppender
log4j.appender.D.File = E://project//LoggerTest//target//log//debug.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://project//LoggerTest//target//log//error.log ###
log4j.appender.E = org.apache.log4j.DailyRollingFileAppender
log4j.appender.E.File = E://project//LoggerTest//target//log//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
### 输出INFO 级别以上的日志到=E://project//LoggerTest//target//log//info.log ###
log4j.appender.I = org.apache.log4j.DailyRollingFileAppender
log4j.appender.I.File = E://project//LoggerTest//target//log//info.log
log4j.appender.I.Append = true
log4j.appender.I.Threshold = INFO
log4j.appender.I.layout = org.apache.log4j.PatternLayout
log4j.appender.I.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss} [ %t:%r ] - [ %p ] %m%n
编写测试代码
package cn.com.gyt;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class LoggerTesting {
public static void main(String[] args) {
Logger logger = LoggerFactory.getLogger("SimpleLogger");
logger.info("info messages!");
logger.debug("debug messages!");
logger.error("error messages!");
}
}
项目结构：
运行： 参考：https://www.yiibai.com/slf4j/slf4j_firstapp.html#article-start
完！
