Windows上如何下载并在Maven上使用log4j

1.  下载log4j的jar包，我下载的apache-log4j-2.X-bin.zip。
2.  将下载解压后的 log4j.jar , log4j-core-2XXX.jar,  log4j-api-2XXX.jar拷贝到 Maven项目-->jars目录下
3.  在Maven中将step2中的三个jar包添加到项目中。右键单击maven项目-->Open Module setting, 点击“添加”按钮，选择这三个jar包，然后应用即可生效。
4. 创建并配置log4j2.xml如下，并将文件拷贝到Maven项目-->Config目录下

5. 
   
       
           ${date:yyyy-MM-dd}
           
           %d{yyyy-MM-dd HH:mm:ss.SSS} [%t] [%-5level] - %l - %msg%n
       
   
       
           
               
           
           
           
               
           
           
           
               
               
               
               
                   
                   
                   
               
               
           
           
               
               
               
                   
                   
                   
               
               
               
           
           
               
               
               
                   
                   
                   
               
               
           
       
       
           
           
           
           
           
           
               
            
               
               
               
               
               
               
               
               
               
           
       
   

   创建并初始化log4j.java,此文件应放置在Maven项目-->src-->main-->java目录下

6. import org.apache.logging.log4j.core.config.ConfigurationSource;
   import org.apache.logging.log4j.core.config.Configurator;
   
   import java.io.File;
   import java.io.FileInputStream;
   
   public class log4j {
       public static void initialLog(){
           try{
               // Config配置的路径为log4j2.xml所在的路径
               File config = new File(System.getProperty("user.dir") + "\\config\\log4j2.xml");
               ConfigurationSource source = new ConfigurationSource(new FileInputStream(config), config);
               Configurator.initialize(null, source);
           } catch (Exception e) {
               e.printStackTrace();
           }
       }
   }

    安装配置完成，测试log4j ，Log4jTest.java如下:

7. import org.apache.logging.log4j.LogManager;
   
   public class Log4jTest {
       log4j.initialLog();
       private static Logger log = Logger.getLogger(Log4jTest.class);
       public void test() {
           String msg = "Opened database successfully";
           LogManager.getLogger().info(msg);
           LogManager.getLogger().debug("debug");
           LogManager.getLogger().warn("warn");
           LogManager.getLogger().fatal("fatal");
           LogManager.getLogger().error("error");
       }
   }

   运行Log4jTest.java, 打开log-->binance.log, 测试log日志能否输出到Maven项目-->log-->binance.log文件中.

   2018-03-24 21:38:03.802 [main] INFO  Log4jTest.java 11 - Opened database successfully
   2018-03-24 21:38:03.802 [main] DEBUG  Log4jTest.java 12 - debug
   2018-03-24 21:38:03.802 [main] WARN  Log4jTest.java 13 - warn
   2018-03-24 21:38:03.802 [main] FATAL  Log4jTest.java 14 - fatal
   2018-03-24 21:38:03.802 [main] ERROR  Log4jTest.java 15 - error