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3.4.?Basic Examples Illustrating this

3.4.1.?SimpleLayout and FileAppender

Here is a very simplistic example of a program implementing a SimpleLayout and FileAppender:

import org.apache.log4j.Level;
import org.apache.log4j.Logger;
import org.apache.log4j.SimpleLayout;
import org.apache.log4j.FileAppender;
public class simpandfile {
   static Logger logger = Logger.getLogger(simpandfile.class);
   public static void main(String args[]) {
      SimpleLayout layout = new SimpleLayout();

      FileAppender appender = null;
      try {
         appender = new FileAppender(layout,"output1.txt",false);
      } catch(Exception e) {}

      logger.addAppender(appender);
      logger.setLevel((Level) Level.DEBUG);

      logger.debug("Here is some DEBUG");
      logger.info("Here is some INFO");
      logger.warn("Here is some WARN");
      logger.error("Here is some ERROR");
      logger.fatal("Here is some FATAL");
   }
}

You can download it: simpandfile.java. And checkout the output produced: output1.txt.

3.4.2.?HTMLLayout and WriterAppender

Here is a very simplistic example of a program implementing a HTMLLayout and WriterAppender:

import java.io.*;
import org.apache.log4j.Level;
import org.apache.log4j.Logger;
import org.apache.log4j.HTMLLayout;
import org.apache.log4j.WriterAppender;
public class htmlandwrite {
   static Logger logger = Logger.getLogger(htmlandwrite.class);
   public static void main(String args[]) {
      HTMLLayout layout = new HTMLLayout();

      WriterAppender appender = null;
      try {
         FileOutputStream output = new FileOutputStream("output2.html");
         appender = new WriterAppender(layout,output);
      } catch(Exception e) {}

      logger.addAppender(appender);
      logger.setLevel((Level) Level.DEBUG);

      logger.debug("Here is some DEBUG");
      logger.info("Here is some INFO");
      logger.warn("Here is some WARN");
      logger.error("Here is some ERROR");
      logger.fatal("Here is some FATAL");
   }
}

You can download it: htmlandwrite.java. And checkout the output produced: output2.html.

3.4.3.?PatternLayout and ConsoleAppender

Here is a very simplistic example of a program implementing a PatternLayout and ConsoleAppender:

import org.apache.log4j.Level;
import org.apache.log4j.Logger;
import org.apache.log4j.PatternLayout;
import org.apache.log4j.ConsoleAppender;
public class consandpatt {
   static Logger logger = Logger.getLogger(consandpatt.class);
   public static void main(String args[]) {

      // Note, %n is newline
      String pattern =  "Milliseconds since program start: %r %n";
             pattern += "Classname of caller: %C %n";
             pattern += "Date in ISO8601 format: %d{ISO8601} %n";
             pattern += "Location of log event: %l %n";
             pattern += "Message: %m %n %n"; 
      
      PatternLayout layout = new PatternLayout(pattern);
      ConsoleAppender appender = new ConsoleAppender(layout);

      logger.addAppender(appender);
      logger.setLevel((Level) Level.DEBUG);

      logger.debug("Here is some DEBUG");
      logger.info("Here is some INFO");
      logger.warn("Here is some WARN");
      logger.error("Here is some ERROR");
      logger.fatal("Here is some FATAL");
   }
}