LOG4j(Logging for java)

Need of Logging:To keep Track of Flow of Execution Related to an Application
Logging, or writing the state of a program at various stages of its execution to some repository such as a log file, is an age-old method used for debugging and monitoring applications.
                              As of now we print log messages in console only by using System.out.println().By using Log4j we can print log messages in console,files,htmlpages,jsp pages.........etc.
(Note:   Alternative to System.out.println())

Type : Logging for java
(LoggingAPI to generate log messages)
Vendor : ApacheFoundation
Opensource s/w
Jar file that represents Log4jAPI : log4j-version.jar

Logically, log4j can be viewed as being comprised of three main components:     
            
             logger-------------> Logger            (step1)
             appender ---------->Appender          (step2)   
             layout ----------------->Layout             (step3)

sample progarme 1:(note:add log4j.jar in the CLASSPATH before running this programme.)
import org.apache.log4j.Appender;
import org.apache.log4j.ConsoleAppender;
import org.apache.log4j.Layout;
import org.apache.log4j.Level;
import org.apache.log4j.Logger;
import org.apache.log4j.SimpleLayout;

public class LogExample {

    public LogExample() {
    }
  

    public static void main(String argsp[]) {
       
//crete logger object(step1)
        Logger log = Logger.getLogger(LogExample.class);
//createLayout object(step2)
        Layout lay=new SimpleLayout();
//create Appender objevt(Step3)
        Appender ap=new ConsoleAppender(lay);

        log.addAppender(ap);
        log.setLevel(Level.WARN);         //default logger level is"DEBUG"
        log.debug("projectname-modulename-Class-method-Here is some DEBUG");
        log.info("projectname-modulename-Class-method-Here is some INFO");
        log.warn("projectname-modulename-Class-method-Here is some WARN");
        log.error("projectname-modulename-Class-method-Here is some ERROR");
        log.fatal("projectname-modulename-Class-method-Here is some FATAL");
      
     
   }
}

sample programme 2:(printing log messages in a file)

//FileAppender

public class Example2  {
   
    public static void main(String a[])
    {
        Logger l=Logger.getLogger(Example2.class);
          try{
    Layout lay=new SimpleLayout();
    FileAppender ap=new FileAppender(lay,"hklwurjrk2.txt",true);
    l.addAppender(ap);
    l.setLevel(Level.DEBUG);
          }catch(Exception d)
          {
              l.debug("log4j stmts problem");
          }
    try{
    Class.forName("oracle.jdbc.driver.OracleDriver");
    l.debug("driver loaded......");
    Connection con=DriverManager.getConnection("jdbc:oracle:thin:@192.168.1.214:1521:XE","kiran","kiran");
    l.info("connection established successfully..........");
   
      }catch(Exception e)
      {
          l.fatal("Db Problem");
          e.printStackTrace();
      }
       
    }
}


sample programe:(using properties file)

prop.properties:(each time comment one execute(# symble used here for commeting))
     
#log4j.rootLogger=debug, stdout
#log4j.appender.stdout=org.apache.log4j.ConsoleAppender
#log4j.appender.stdout.Target=System.out
#log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
#log4j.appender.stdout.layout.ConversionPattern=%t %-5p %c{2} - %m%n




#log4j.rootLogger=debug, stdout
#log4j.appender.stdout=org.apache.log4j.FileAppender
#log4j.appender.stdout.File=src/logs/msg2.txt
#log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
#log4j.appender.stdout.layout.ConversionPattern=%r  [%t]  %p  %c  %m  %d  %n             




#log4j.rootLogger=debug, stdout
#log4j.appender.stdout=org.apache.log4j.FileAppender
#log4j.appender.stdout.File=msg1.html
#log4j.appender.stdout.layout=org.apache.log4j.HTMLLayout




#log4j.rootLogger=debug, stdout
#log4j.appender.stdout=org.apache.log4j.RollingFileAppender
#log4j.appender.stdout.File=src/logs/rollfile666666.txt
#log4j.appender.stdout.MaxFileSize=2kb
#log4j.appender.stdout.MaxBackupIndex=5
#log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
#log4j.appender.stdout.layout.ConversionPattern=%r  [%t]  %p  %c  %m  %d  %n       




log4j.rootLogger=debug, stdout
log4j.appender.stdout=org.apache.log4j.DailyRollingFileAppender
log4j.appender.stdout.File=logs/dailyrollfile3333.txt
log4j.appender.stdout.DatePattern='.'yyyy-MM-dd-HH-mm
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%r  [%t]  %p  %c  %m  %d  %n                   




Example2.java:
import org.apache.log4j.Level;
import org.apache.log4j.Logger;
import org.apache.log4j.PropertyConfigurator;


public class Example2  {
   
    public static void main(String a[])
    {
        Logger l=Logger.getLogger(Example2.class);
   
        PropertyConfigurator.configure("src/prop.properties");
        
          l.setLevel(Level.DEBUG);
          l.debug("Myprojectname-modulename-Class-method-ok executedddddddddddddd");
          l.info("projectname-modulename-Class-method-some infoooooooooo");
          l.warn("projectname-modulename-Class-method-warn msg");
          l.error("projectname-modulename-Class-method-error msg......");
          l.fatal("projectname-modulename-Class-method-this is some fatal errrrrrrr");
    }
}

Friends Chat

Hi Friends Login and chat...........,(NOTE:youe system must have java installation)

JBOSS

                                                    Downloading JBOSS Application Server
Step 1: - Download jboss-5.1.0.GA.zip and extract the zip file to jboss-5.1.0.GA folder
You can get this from http://sourceforge.net/projects/jboss/files/JBoss/JBoss-5.1.0.GA/jboss-5.1.0.GA-jdk6.zip/download

Step 2: one dialogue box will pop up on the screen.click OK button to save the jboss5.1.0.GA-jdk6.zip
Step3: Unzip this file that you just downloaded. On most Windows machines Right-click the file. Move to the Win Zip command. Click Extract to here It creates a folder named jboss-5.1.0.GA. You can leave this folder here or move it elsewhere on your disk drive
Step 4: Prerequisites Before installing and running the server, check your system to make sure you have a working JDK 1.6 installation. The simplest way to do this is to execute the Java -version command to ensure that the Java executable is in your path.
Step 5 : - Open jboss-5.1.0.GA\bin Folder and click run.bat file for starting server.
Path: jboss-5.1.0.GA\bin\run.bat
Step 6: - The server runs default on the port number 8080
NOTE:If Any Exceptions are occurred in starting of the server you have to change the port number.
To change the Port number,open server.xml file in Jboss-5.1.0.GA. Path:(Jbosshome directory)jboss-5.1.0.GA\server\default\deploy\jbossweb.sar\server.xml Open server.xml and change the port number at the first <connector>tag. And restart the server.

                                                       Configuring JBOSS in Eclipse
Step1: Open Eclipse Ganymede ,Right click on the server tab --->New----> Server.
step2 Select Jboss Folder and click on jboss v5.0 and click Next button.
Step3: Click Browse button and select the JBoss Home Directory and then click Next--->Next--->Finish.