With this example we are going to demonstrate how to set a Formatter for a Logger Handler. The Formatter is used by the Handler to format LogRecords. In short, to set a Formatter for a Logger’s handler you should:
- Create a new Logger instance with
getLogger(String name)API method of Logger. - Create a new FileHandler to write to a specific file.
- Add the handler to the Logger, with
addHandler(Handler handler)API method of Logger. - Set a Formatter to the Handler, with
setFormatter(Formatter newFormatter)API method. In the example we use the SimpleFormatter and the XMLFormatter.
Let’s take a look at the code snippet that follows:
01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 | package com.javacodegeeks.snippets.core;import java.util.logging.FileHandler;import java.util.logging.Logger;import java.util.logging.SimpleFormatter;import java.util.logging.XMLFormatter;public class SetFormatterForLoggerHandler { public static void main(String[] args) throws Exception { boolean append = false; FileHandler handler = new FileHandler("default.log", append); Logger logger = Logger.getLogger("com.javacodegeeks.snippets.core"); logger.addHandler(handler); handler.setFormatter(new SimpleFormatter()); logger.info("simple formatter - info message"); handler.setFormatter(new XMLFormatter()); logger.info("xml formatter - info message"); }} |
Output:
Nov 19, 2011 4:03:15 PM com.javacodegeeks.snippets.core.SetFormatterForLoggerHandler main
INFO: simple formatter - info message
Nov 19, 2011 4:03:15 PM com.javacodegeeks.snippets.core.SetFormatterForLoggerHandler main
INFO: xml formatter - info message
default.log
01 02 03 04 05 06 07 08 09 10 11 12 13 14 | Nov 19, 2011 4:03:15 PM com.javacodegeeks.snippets.core.SetFormatterForLoggerHandler mainINFO: simple formatter - info message<record> <date>2011-11-19T16:03:15</date> <millis>1321711395420</millis> <sequence>1</sequence> <logger>com.javacodegeeks.snippets.core</logger> <level>INFO</level> <class>com.javacodegeeks.snippets.core.SetFormatterForLoggerHandler</class> <method>main</method> <thread>10</thread> <message>xml formatter - info message</message></record></log> |
This was an example of how to set a Formatter for a Logger Handler in Java.
