Build a Custom Formatter for a Java.util.logging Logger

For a simple custom logger, you can inherit from the base java.util.logging.Formatter class and override its format method to customize the output. Here's an example:

import java.io.*;
import java.util.*;
import java.util.logging.*;

public class CustomFormatter extends java.util.logging.Formatter 
{
   public String format(LogRecord log) 
   {
      Date date = new Date(log.getMillis());
      String level = log.getLevel().getName();
      String logmessage = "{"+level+"}" + "{"+date.toString()+"}\r\n";
      logmessage = logmessage + log.getMessage() + "\r\n\r\n";
         
      Throwable thrown = log.getThrown();
      if (thrown != null) { 
         logmessage = logmessage + thrown.toString(); 
      }
      return logmessage;
   }
}