Log4j 引入项目

方式一：导入log4j的jar包

方式二：新建一个maven项目，通过maven导入log4j

New Maven project
  create a simple project(skip archetype selection)
Artifact
  Group Id: com.open1111
  Artifact Id: Log4jTest
  Version: 0.0.1-SNAPSHOT
  Packaging: jar

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.open1111</groupId>
  <artifactId>Log4jTest</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <dependencies>
      <dependency>
        <groupId>log4j</groupId>
        <artifactId>log4j</artifactId>
        <version>1.2.17</version>
    </dependency>
  </dependencies>
</project>

log4j.rootLogger=DEBUG, Console ,File

#Console  
log4j.appender.Console=org.apache.log4j.ConsoleAppender  
log4j.appender.Console.layout=org.apache.log4j.PatternLayout  
log4j.appender.Console.layout.ConversionPattern=%d [%t] %-5p [%c] - %m%n

#File
log4j.appender.File = org.apache.log4j.FileAppender
log4j.appender.File.File = E://log4j-test-log.log
log4j.appender.File.layout = org.apache.log4j.PatternLayout
log4j.appender.File.layout.ConversionPattern =%d [%t] %-5p [%c] - %m%n

package com.open1111;
import org.apache.log4j.Logger;
public class Test {
    private static Logger logger = Logger.getLogger(Test.class);
    public static void main(String[] args) {
        logger.fatal("严重错误fatal信息");
        logger.error("报错error信息");
        logger.error("报错信息", new IllegalArgumentException("非法参数"));
        logger.warn("警告warn信息");
        logger.info("普通Info信息");
        logger.debug("调试debug信息");
    }
}
运行结果：
控制台打印信息
生产log文件：E://log4j-test-log.log