Java by API/java.util.logging/Level

Level.ALL

   <source lang="java">
 

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 Main {

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

}

 </source>
   
  
 
  

Level.FINEST

   <source lang="java">
 

import java.util.logging.Level; import java.util.logging.Logger; public class Main {

 private static Logger
   lgr = Logger.getLogger("com"),
   lgr2 = Logger.getLogger("com.jexp"),
   util = Logger.getLogger("com.jexp.util"),
   test = Logger.getLogger("com.jexp.test"),
   rand = Logger.getLogger("random");
   
 private static void logMessages() {
   lgr.info("com : info");
   lgr2.info("com.abc : info");
   util.info("util : info");
   test.severe("test : severe");
   rand.info("random : info");
 }
 public static void main(String[] args) {
   lgr.setLevel(Level.SEVERE);
   System.out.println("com level: SEVERE");
   logMessages();
   util.setLevel(Level.FINEST);
   test.setLevel(Level.FINEST);
   rand.setLevel(Level.FINEST);
   System.out.println("individual loggers set to FINEST");
   logMessages();
   lgr.setLevel(Level.SEVERE);
   System.out.println("com level: SEVERE");
   logMessages();
 }

}

 </source>
   
  
 
  

Level.SEVERE

   <source lang="java">
 

import java.util.logging.Level; import java.util.logging.Logger; public class Main {

 private static Logger
   lgr = Logger.getLogger("com"),
   lgr2 = Logger.getLogger("com.jexp"),
   util = Logger.getLogger("com.jexp.util"),
   test = Logger.getLogger("com.jexp.test"),
   rand = Logger.getLogger("random");
   
 private static void logMessages() {
   lgr.info("com : info");
   lgr2.info("com.abc : info");
   util.info("util : info");
   test.severe("test : severe");
   rand.info("random : info");
 }
 public static void main(String[] args) {
   lgr.setLevel(Level.SEVERE);
   System.out.println("com level: SEVERE");
   logMessages();
   util.setLevel(Level.FINEST);
   test.setLevel(Level.FINEST);
   rand.setLevel(Level.FINEST);
   System.out.println("individual loggers set to FINEST");
   logMessages();
   lgr.setLevel(Level.SEVERE);
   System.out.println("com level: SEVERE");
   logMessages();
 }

}

 </source>
   
  
 
  

Level.WARNING

   <source lang="java">
 

// : c15:SimpleFilter.java // From "Thinking in Java, 3rd ed." (c) Bruce Eckel 2002 // www.BruceEckel.ru. See copyright notice in CopyRight.txt. import java.util.logging.Filter; import java.util.logging.Level; import java.util.logging.LogRecord; import java.util.logging.Logger; public class SimpleFilter {

 private static Logger logger = Logger.getLogger("SimpleFilter");
 static class Duck {
 };
 static class Wombat {
 };
 static void sendLogMessages() {
   logger.log(Level.WARNING, "A duck in the house!", new Duck());
   logger.log(Level.WARNING, "A Wombat at large!", new Wombat());
 }
 public static void main(String[] args) {
   sendLogMessages();
   logger.setFilter(new Filter() {
     public boolean isLoggable(LogRecord record) {
       Object[] params = record.getParameters();
       if (params == null)
         return true; // No parameters
       if (record.getParameters()[0] instanceof Duck)
         return true; // Only log Ducks
       return false;
     }
   });
   logger.info("After setting filter..");
   sendLogMessages();
 }

} ///:~

 </source>