Using Regular Expressions based on StreamHandler : Log Handler « Log « Java Tutorial

1. Java Tutorial
2. Log
3. Log Handler

import java.util.logging.Handler;
import java.util.logging.Level;
import java.util.logging.LogRecord;
import java.util.logging.Logger;
import java.util.logging.StreamHandler;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class MainClass {
  public static void main(String args[]) {
    Logger log = Logger.getAnonymousLogger();
    setLoggerhandler(log);

    log.finest(new Exception().toString());
  }

  public static void setLoggerhandler(Logger logger) {
    Handler handler = new ExceptionHandler();
    logger.addHandler(handler);

    logger.setLevel(Level.ALL);
  }
}

class ExceptionHandler extends StreamHandler {
  public void publish(LogRecord record) {
    String msg = record.getMessage();
    int exceptionIndex = msg.indexOf("Exception");

    if (exceptionIndex > -1) {
      Pattern pattern = Pattern.compile("(.*Exception.*)");

      Matcher matcher = pattern.matcher(msg);

      if (matcher != null && matcher.find()) {
        String err = "EXCEPTION FOUND " + matcher.group(1);
        System.out.println(err);
      }
    }
  }
}