Simple log4j example by using xml file in Java

copy log4j2.xml in resource folder

 <?xml version="1.0" encoding="UTF-8"?>  
 <Configuration>  
  <Appenders>  
   <!-- Console Appender -->  
   <Console name="Console" target="SYSTEM_OUT">  
    <PatternLayout pattern="%d{yyyy-MMM-dd HH:mm:ss a} [%t] %-5level %logger{36} - %msg%n" />  
   </Console>  
   <!-- Rolling File Appender -->  
   <RollingFile name="RollingFile">  
    <FileName>C:/Users/Mutturaj/workspace/ExtentReports/log/mylog.log</FileName>  
    <FilePattern>C:/log/size-based-logs/%d{yyyy-MM-dd-hh}-%i.log.zip</FilePattern>  
    <PatternLayout>  
     <Pattern>%d{yyyy-MMM-dd HH:mm:ss a} [%t] %-5level %logger{36} - %msg%n</Pattern>  
    </PatternLayout>  
    <Policies>  
     <SizeBasedTriggeringPolicy size="10 KB" />  
    </Policies>  
    <DefaultRolloverStrategy max="5" />  
   </RollingFile>  
  </Appenders>  
  <Loggers>  
   <Logger name="extentReportForMultipleTestsInAClass" level="debug" additivity="false">  
    <AppenderRef ref="RollingFile" />  
    <AppenderRef ref="Console" />  
   </Logger>  
   <Root level="trace">  
    <AppenderRef ref="Console" />  
   </Root>  
  </Loggers>  
 </Configuration>  

create a logger in your class

      private static final Logger log=LogManager.getLogger(ClassA.class);  

Here is the class

 package extentReportForMultipleTestsInAClass;  
 import org.apache.logging.log4j.LogManager;  
 import org.apache.logging.log4j.Logger;  
 import org.testng.Assert;  
 import org.testng.annotations.Test;  
 public class ClassA extends BaseTest {  
      private static final Logger log=LogManager.getLogger(ClassA.class);  
      @Test  
      public void method1() {  
           log.info("Method 1 started");  
           test = extent.createTest("method1");  
           driver.get("https://www.facebook.com/");  
           String title = driver.getTitle();  
           System.out.println(title);  
           log.info(title);  
           Assert.assertEquals(title, "Facebook – log");  
      }  
      @Test  
      public void method2() {  
           log.info("Method 2 started");  
           test = extent.createTest("method1");  
           driver.get("https://www.facebook.com/");  
           String title = driver.getTitle();  
           System.out.println(title);  
           log.info(title);  
           Assert.assertEquals(title, "Facebook – log");  
      }  
 }  

add these 2 dependencies in POM.xml file

 <dependency>  
                <groupId>org.apache.logging.log4j</groupId>  
                <artifactId>log4j-api</artifactId>  
                <version>2.11.2</version>  
           </dependency>  
           <dependency>  
                <groupId>org.apache.logging.log4j</groupId>  
                <artifactId>log4j-core</artifactId>  
                <version>2.11.2</version>  
           </dependency>  

your log file looks like below:)

 2019-May-05 11:13:03 AM [main] INFO extentReportForMultipleTestsInAClass.ClassA - Method 1 started  
 2019-May-05 11:13:06 AM [main] INFO extentReportForMultipleTestsInAClass.ClassA - Facebook – log in or sign up  
 2019-May-05 11:13:12 AM [main] INFO extentReportForMultipleTestsInAClass.ClassA - Method 2 started  
 2019-May-05 11:13:15 AM [main] INFO extentReportForMultipleTestsInAClass.ClassA - Facebook – log in or sign up  
 2019-May-05 11:15:43 AM [main] INFO extentReportForMultipleTestsInAClass.ClassA - Method 1 started  
 2019-May-05 11:15:47 AM [main] INFO extentReportForMultipleTestsInAClass.ClassA - Facebook – log in or sign up  
 2019-May-05 11:15:53 AM [main] INFO extentReportForMultipleTestsInAClass.ClassA - Method 2 started  
 2019-May-05 11:15:57 AM [main] INFO extentReportForMultipleTestsInAClass.ClassA - Facebook – log in or sign up  
 2019-May-05 11:16:03 AM [main] INFO extentReportForMultipleTestsInAClass.ClassB - Method 1 started  

Let me know what you think in the comment:) Happy coding!