Apache Commons Logging

Apache Commons Logging (previously known as Jakarta Commons Logging or JCL) is a Java-based logging utility and a programming model for logging and for other toolkits. It provides APIs, log implementations, and wrapper implementations over some other tools.

Apache Commons Logging (previously known as Jakarta Commons Logging or JCL) is a Java-based logging utility and a programming model for logging and for other toolkits. It provides APIs, log implementations, and wrapper implementations over some other tools. package com.cascadetg.ch09; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.commons.logging.impl.Jdk14Logger; public class LogGenerator { // Note that you pass in an instance of this class to the // log generator. This allows you to find the messages // generated by this class. private static Log log = LogFactory.getLog(LogGenerator.class); public static void configJDKLogger() { try { ((Jdk14Logger)log).getLogger().setLevel( java.util.logging.Level.ALL); ((Jdk14Logger)log).getLogger().addHandler( (java.util.logging.FileHandler)Class .forName("java.util.logging.FileHandler") .newInstance()); System.out.println("Added JDK 1.4 file handler"); } catch (Exception e) { System.out.println("Unable to load JDK 1.4 logging."); e.printStackTrace(); } } public static void main(String[] args) { configJDKLogger(); System.setErr(System.out); System.out.println(); System.out.println("Test fatal log"); try { String foo = null; int x = 0 / (new Integer(foo)).intValue(); } catch (Exception e) { log.fatal(e.getMessage(), e); } System.out.println(); System.out.println("Test error log"); try { Object foo = null; foo.toString(); } catch (Exception e) { log.error(e.getMessage(), e); } System.out.println(); System.out.println("Test warn log"); try { Class.forName("com.cascadetg.NonexistentClass"); } catch (Exception e) { log.warn("Can't find a nonexistent class!"); } System.out.println(); System.out.println("Test info log"); log.info("Starting app!"); log.info("Quitting app!"); System.out.println(); System.out.println("Test debug log"); if (1 > 2) { log.debug("1 > 2 evaluated true"); if (10 % 2 == 0) log.debug("10 % 2 is 0"); else log.debug("10 % 2 is not 0"); } else { log.debug("1 > 2 evaluated false"); } System.out.println(); System.out.println("Test trace log"); log.trace("Calling trace method."); log.trace("Calling trace method."); log.trace("Calling trace method."); log.trace("Calling trace method."); log.trace("Calling trace method."); System.out.println(); System.out.println("Log test complete."); } }

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