Log4j with Selenium Tutorial: Download, Install, Use & Example

Details

What is Log4j?

Log4j is a fast, flexible and reliable logging framework (APIS) written in Java developed in early 1996. It is distributed under the Apache Software License. Log4J has been ported to the C, C++, C#, Perl, Python, Ruby and Eiffel Languages. It is a tool used for small to large scale Selenium Automation projects.

Why use Log4j?

Log4j has three principal components

Log4j with Selenium Tutorial

  1. Loggers: It is responsible for logging information. To implement loggers into a project following steps need to be performed -
  1. Appenders: It is used to deliver LogEvents to their destination. It decides what will happen with log information. In simple words, it is used to write the logs in file. Following are few types of Appenders
    1. ConsoleAppender logs to standard output
    2. File appender prints logs to some file
    3. Rolling file appender to a file with maximum size

    Note: In log4j properties we can call appender with any name. There are other appenders as well but we will restrict to these few.

  2. Layouts: It is responsible for formatting logging information in different styles.

The Logger class provides different methods to handle logging activities. It provides two static methods for obtaining a Logger Object. 

Public static Logger getRootLogger()
Public static Logger getLogger(String name)

How log4j is configured?

To configure log4j we have to decide which appender to implement. Accordingly, parameters of appender will be set.

#Root logger 

log4j.rootLogger=DEBUG,file
log4j.appender.file=org.apache.log4j.RollingFileAppender
log4j.appender.file.File=D:\\gtupapers\\src\\Selenium.logs
log4j.appender.file.maxFileSize=900KB
log4j.appender.file.maxBackupIndex=5
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=%d{ABSOLUTE} %5p %c<strong>{1}</strong>:%L - %m%n
log4j.appender.file.Append=false

#Application Logs 

log4j.logger.devpinoyLogger=DEBUG, dest1
log4j.appender.dest1=org.apache.log4j.RollingFileAppender
log4j.appender.dest1.maxFileSize=900KB
log4j.appender.dest1.maxBackupIndex=6
log4j.appender.dest1.layout=org.apache.log4j.PatternLayout
log4j.appender.dest1.layout.ConversionPattern=%d{dd/MM/yyyy HH:mm:ss} %c %m%n
log4j.appender.dest1.File=D:\\ gtupapers\\src\\Manual.logs
log4j.appender.dest1.Append=false

In the above Example, we have configured log4j to log in two different files named as Selenium.log and Manual.log.

How log4j is used within script?

In code, we have used "log" as a reference variable referencing getLogger method of Logger Class 

Logger log = Logger.getLogger("devpinoyLogger");

Use "log" referencing variable and debug method to log the information we want. 

log.debug("--information--");

What is a LogExpert tool?

  1. LogExpert tool is a tool for Windows developed to tail the logs
  2. It is free and open source log viewer.
  3. It is a log analysis tool with multiple features like searching, filtering, bookmarking and highlighting the logs
  4. In this tool logs, files get automatically updated when opened
  5. In this tool, we can open multiple log file in different tabs
  6. We can also put comments on bookmarks, and there is the shortcut key to navigate in between different bookmarks. We can also see complete bookmark list and navigate from there
  7. Shortcuts of the tool are given in help file so that they can be referred to the tool.

Steps to use Log4j with Selenium

Step 1) In Eclipse create a new project with name log4j_demo

Log4j with Selenium Tutorial

Step 2) Right click on src -> Build Path -> Configure Build Path

Log4j with Selenium Tutorial

Step 2) Click on Libraries and Add Log4J Library . You can download it from https://logging.apache.org/log4j/1.2/download.html

 

Log4j with Selenium Tutorial

Step 3) Create a new file. This file will include all the log4j configuration

  1. Right click on src -> New -> Other -> General -> File
  2. Give the file name as "log4j.properties"
  3. Click on Finish

Create two more files and give them names such as Selenium.logs and Manual.logs. These files will contain all the logs created by system and manually logged statements

Log4j with Selenium Tutorial

Step 4) In log4j.properties copy the entire configuration.

Log4j with Selenium Tutorial

Step 5) Create main class:

  1. Right click on default package -> New -> Class
  2. Give the class name and click on finish

Log4j with Selenium Tutorial

Step 6) Copy the following code in to the main class 

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.firefox.FirefoxDriver;
import org.apache.log4j.Logger;

public class LoggingDemo {
    /**
		* @param args
    */
    public static void main(String[] args) {
         // TODO Auto-generated method stub
         WebDriver driver = new FirefoxDriver();
         Logger log = Logger.getLogger("devpinoyLogger");
         
         driver.get("http://healthunify.com/bmicalculator/");
		 log.debug("opening webiste");
         driver.manage().timeouts().implicitlyWait(20, TimeUnit.SECONDS);
		 log.debug("entring weight");
		 driver.findElement(By.name("wg")).sendKeys("87");
         log.debug("selecting kilograms");
         driver.findElement(By.name("opt1")).sendKeys("kilograms");
         log.debug("selecting height in feet");
         driver.findElement(By.name("opt2")).sendKeys("5");
         log.debug("selecting height in inchs");
         driver.findElement(By.name("opt3")).sendKeys("10");
         log.debug("Clicking on calculate");
         driver.findElement(By.name("cc")).click();

		 log.debug("Getting SIUnit value");
         String SIUnit = driver.findElement(By.name("si")).getAttribute("value");
         log.debug("Getting USUnit value");
         String USUnit = driver.findElement(By.name("us")).getAttribute("value");
         log.debug("Getting UKUnit value");
         String UKUnit = driver.findElement(By.name("uk")).getAttribute("value");
         log.debug("Getting overall description");
         String note = driver.findElement(By.name("desc")).getAttribute("value");
      
         System.out.println("SIUnit = " + SIUnit);
         System.out.println("USUnit = " + USUnit);
         System.out.println("UKUnit = " + UKUnit);
         System.out.println("note = " + note); 
		driver.quit();
	}
}

In the above code, we visit http://healthunify.com/bmicalculator/and verify BMI calculator. The weight entered is 87KG and the height is 5 Feet 10 inches. The script checks output in SE, US and UK units.

Using Logger.getLogger("devpinoyLogger") we create system level logs

Using log.debug method we store data into Manual.log

Step 7) Run the script. Open the location of Manual and Selenium logs to check logging data.

How LogExpert tool can be used to analyze logs

  1. Download the tool from http://logexpert.codeplex.com/ . Go to LogExpert download folder

    Log4j with Selenium Tutorial

  2. Open LogExpert.exe
  3. Click on File -> Open and Browse to the path where Manual.log and Selenium.log files are stored. Select the file
  4. Select the "Follow tail" option

    Log4j with Selenium Tutorial

    Selecting follow tail option enables tailing of logs which means LogExpert automatically updates the log file when script is in execution phase. If we use any other editor like notepad then we have to close and reopen the file again and again to update the logs. But with ExpertTool in Follow Tail Mode this is not required.

    Following images shows the layout of the logs

    Log4j with Selenium Tutorial

    Log4j with Selenium Tutorial

Using LogExpert tool, one can debug logs created by the selenium webdriver as in this tool once can

This tool also helps to partition the data into different columns.

 

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