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()+"}
";      logmessage = logmessage + log.getMessage() + "

";               Throwable thrown = log.getThrown();      if (thrown != null) {          logmessage = logmessage + thrown.toString();       }      return logmessage;   }}