Java Logging

1. The java logging is present in java.util.logging package.
2. The logging service is useful for developers, administrator and service engineers for their debugging work.
3.  Different levels  of logging are:-

       SEVERE (highest value)
       WARNING
       INFO
       CONFIG
       FINE
       FINER
       FINEST (lowest value)

4. Set up the Project :-

5.  JavaHtmlLoggerFormatter.java

       This is a custom formater to log the differernt log messages in html format

package com.sandeep.logging.example;

import java.util.logging.Formatter;
import java.util.logging.Level;
import java.util.logging.LogRecord;

public class JavaHtmlLoggerFormatter  extends Formatter{

 @SuppressWarnings("static-access")
 @Override
 public String format(LogRecord record) {
  
     StringBuffer html = new StringBuffer();
  
     if(Level.SEVERE.intValue() == record.getLevel().SEVERE.intValue()){
      
      html.append("
"+formatMessage(record)+"");
     }
     if(Level.WARNING.intValue() == record.getLevel().WARNING.intValue()){
      
      html.append("






"+formatMessage(record)+"");
     }
  return html.toString();
 }

}

6. DemoLogger.java

package com.sandeep.logging.example;

import java.io.IOException;
import java.util.logging.Formatter;
import java.util.logging.FileHandler;
import java.util.logging.Level;
import java.util.logging.Logger;

public class DemoLogger {

 
   static private FileHandler htmlFile;
   static private Formatter  htmlFormatter;

   static public void setup() throws IOException {
    
     Logger logger = Logger.getLogger("");
     logger.setLevel(Level.SEVERE);
     htmlFile = new FileHandler("D:\LogFile.html");
     htmlFormatter = new JavaHtmlLoggerFormatter();
     htmlFile.setFormatter(htmlFormatter);
     logger.addHandler(htmlFile);
     
     
   }
 
}

7. JavaLoggingDemo.java

This java file shows how to use it

package com.sandeep.logging.example;

import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;

public class JavaLoggingDemo {

 private final static Logger LOGGER = Logger.getLogger(JavaLoggingDemo.class .getName());
 
 public static void main(String[] args) {
  
  
  try {
   DemoLogger.setup();
  } catch (IOException e) {
   e.printStackTrace();
  }
  LOGGER.log(Level.SEVERE, " This is a Severe error");
  LOGGER.log(Level.SEVERE, "This is a warning");
  
  
 }

}

8.Output in D drive

Download the project:-

Java Logging Demo Project