How to print logs using log4j in selenium webdriver

Question

Environment: Java, Selenium webdriver, Maven, testNG, Log4J, Eclipse

1. XML

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE suite SYSTEM "http://testng.org/testng-1.0.dtd" >
<suite name="TestAll" parallel = "tests" thread-count = "2">

 <test name="postivelogintest_IE">
 <parameter name="browser" value="ie"/>

 <classes>
 <class name="com.dice.LoginTest">
 <methods>
 <include name="DataDrivenpositiveLoginTest"/>
 </methods>
 </class>
 </classes>
 </test>


 <test name="postivelogintest_CH">
 <parameter name="browser" value="ch"/>

 <classes>
 <class name="com.dice.LoginTest">
 <methods>
 <include name="DataDrivenpositiveLoginTest"/>
 </methods>
 </class>
 </classes>
 </test>


</suite>

2. BaseTest.java

package com.diceBase;
import org.apache.log4j.Logger;
import org.openqa.selenium.WebDriver;
import org.testng.annotations.AfterMethod;
import org.testng.annotations.BeforeMethod;
import org.testng.annotations.Parameters;




public class BaseTest {
 protected WebDriver driver;
 protected Logger log;

    @Parameters ({"browser"})
 @BeforeMethod
 protected void MethodSetup(String browser){
 log.info("method set up"); // line 16
 driver = BrowserFactory.getDriver(browser);
 }

 @AfterMethod
 protected void TearDown(){
 log.info("method tear down");


 try {
 Thread.sleep(5000);
 driver.quit();
 } catch (Exception e) {
 }
 }
}

3. I added log4j.properties under src/main/resources.

   

4. In the BaseTest.java, I added two lines after importing log4j.

   log.info("method set up");

   log.info("method tear down");

iMy goal is to be able to use log.info entire project. Before that, I would like to test it by only importing log4j logger in basetest class to see if it works. If it works then I can import log4j in entire project.

I get error if I keep both log messages. But, If I remove both log messages, script passes. How can I print the logs using log4j?

Answer 1

The log variable in your BaseTest.java has not assigned with object of logger class (https://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/Logger.html) . Since No object is assigned to the variable log, it throws NULL pointer exception. So please create object of logger class to varaiable log