浅谈在JAVA项目中LOG4J的使用

//输出到项目文件夹下output1.txt文件中//////////////////////////////// DEBUG - Here is some DEBUG// INFO - Here is some INFO// WARN - Here is some WARN// ERROR - Here is some ERROR// FATAL - Here is some FATAL//////////////////////////////package hunnu.sanha.test;import org.apache.log4j.Level;import org.apache.log4j.Logger;import org.apache.log4j.SimpleLayout;import org.apache.log4j.FileAppender;public class Simpandfile { static Logger logger = Logger.getLogger(Simpandfile.class); public static void main(String args[]) {  SimpleLayout layout = new SimpleLayout();  FileAppender appender = null;  try {   appender = new FileAppender(layout,"output1.txt",false);  } catch(Exception e) {}  logger.addAppender(appender);  logger.setLevel((Level) Level.);  logger.debug("Here is some DEBUG");  logger.info("Here is some INFO");  logger.warn("Here is some WARN");  logger.error("Here is some ERROR");  logger.fatal("Here is some FATAL"); }} //按格式输出到项目文件夹下output2.htmlpackage hunnu.sanha.test;import java.io.*;import org.apache.log4j.Level;import org.apache.log4j.Logger;import org.apache.log4j.HTMLLayout;import org.apache.log4j.WriterAppender;public class Htmlandwrite { static Logger logger = Logger.getLogger(Htmlandwrite.class); public static void main(String args[]) {  HTMLLayout layout = new HTMLLayout();  WriterAppender appender = null;  try {   FileOutputStream output = new FileOutputStream("output2.html");   appender = new WriterAppender(layout,output);  } catch(Exception e) {}  logger.addAppender(appender);  logger.setLevel((Level) Level.);  logger.debug("Here is some DEBUG");  logger.info("Here is some INFO");  logger.warn("Here is some WARN");  logger.error("Here is some ERROR");  logger.fatal("Here is some FATAL"); }}  //输出到控制台////////////////////////////////////////////////////////////////////////////////////////////////////////////Milliseconds since program start: 0Classname of caller: hunnu.sanha.test.ConsandpattDate in ISO8601 format: 2008-07-29 11:02:30,578Location of log event: hunnu.sanha.test.Consandpatt.main(Consandpatt.java:20)Message: Here is some DEBUG Milliseconds since program start: 15Classname of caller: hunnu.sanha.test.ConsandpattDate in ISO8601 format: 2008-07-29 11:02:30,593Location of log event: hunnu.sanha.test.Consandpatt.main(Consandpatt.java:21)Message: Here is some INFO Milliseconds since program start: 15Classname of caller: hunnu.sanha.test.ConsandpattDate in ISO8601 format: 2008-07-29 11:02:30,593Location of log event: hunnu.sanha.test.Consandpatt.main(Consandpatt.java:22)Message: Here is some WARN Milliseconds since program start: 15Classname of caller: hunnu.sanha.test.ConsandpattDate in ISO8601 format: 2008-07-29 11:02:30,593Location of log event: hunnu.sanha.test.Consandpatt.main(Consandpatt.java:23)Message: Here is some ERROR Milliseconds since program start: 15Classname of caller: hunnu.sanha.test.ConsandpattDate in ISO8601 format: 2008-07-29 11:02:30,593Location of log event: hunnu.sanha.test.Consandpatt.main(Consandpatt.java:24)Message: Here is some FATAL///////////////////////////////////////////////////////package hunnu.sanha.test;import org.apache.log4j.Level;import org.apache.log4j.Logger;import org.apache.log4j.PatternLayout;import org.apache.log4j.ConsoleAppender;public class Consandpatt { static Logger logger = Logger.getLogger(Consandpatt.class); public static void main(String args[]) {  // Note, %n is newline  String pattern = "Milliseconds since program start: %r %n";    pattern += "Classname of caller: %C %n";    pattern += "Date in ISO8601 format: %d{ISO8601} %n";    pattern += "Location of log event: %l %n";    pattern += "Message: %m %n %n";    PatternLayout layout = new PatternLayout(pattern);  ConsoleAppender appender = new ConsoleAppender(layout);  logger.addAppender(appender);  logger.setLevel((Level) Level.);  logger.debug("Here is some DEBUG");  logger.info("Here is some INFO");  logger.warn("Here is some WARN");  logger.error("Here is some ERROR");  logger.fatal("Here is some FATAL"); }}

//xmllog4jconfig.xml<?xml version="1.0" encoding="UTF-8" ?><!DOCTYPE log4j:configuration SYSTEM "log4j.dtd"><log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/"> <appender name="appender" class="org.apache.log4j.FileAppender">  <param name="File" value="Indentify-Log.txt"/>  <param name="Append" value="false"/>  <layout class="org.apache.log4j.PatternLayout">  <param name="ConversionPattern" value="%d [%t] %p - %m%n"/>  </layout> </appender> <root>  <priority value ="debug"/>  <appender-ref ref="appender"/> </root></log4j:configuration> //Externalxmltest.java package hunnu.sanha.external;import org.apache.log4j.Logger;import org.apache.log4j.xml.DOMConfigurator;public class Externalxmltest { static Logger logger = Logger.getLogger(Externalxmltest.class); public static void main(String args[]) {  DOMConfigurator.configure("xmllog4jconfig.xml");  logger.debug("Here is some DEBUG");  logger.info("Here is some INFO");  logger.warn("Here is some WARN");  logger.error("Here is some ERROR");  logger.fatal("Here is some FATAL"); }}//结果输出到Indentify-Log.txt文件中2008-07-29 10:48:11,375 [main] DEBUG - Here is some DEBUG2008-07-29 10:48:11,375 [main] INFO - Here is some INFO2008-07-29 10:48:11,375 [main] WARN - Here is some WARN2008-07-29 10:48:11,375 [main] ERROR - Here is some ERROR2008-07-29 10:48:11,375 [main] FATAL - Here is some FATAL  // plainlog4jconfig.txt# initialise root logger with level DEBUG and call it BLAHlog4j.rootLogger=DEBUG, BLAH# add a ConsoleAppender to the logger BLAHlog4j.appender.BLAH=org.apache.log4j.ConsoleAppender# set set that layout to be SimpleLayoutlog4j.appender.BLAH.layout=org.apache.log4j.SimpleLayout //Externalplaintest.javapackage hunnu.sanha.external;import org.apache.log4j.Logger;import org.apache.log4j.PropertyConfigurator;public class Externalplaintest { static Logger logger = Logger.getLogger(Externalplaintest.class); public static void main(String args[]) {  PropertyConfigurator.configure("plainlog4jconfig.txt");  logger.debug("Here is some DEBUG");  logger.info("Here is some INFO");  logger.warn("Here is some WARN");  logger.error("Here is some ERROR");  logger.fatal("Here is some FATAL"); }}//结果输出到控制台DEBUG - Here is some DEBUGINFO - Here is some INFOWARN - Here is some WARNERROR - Here is some ERRORFATAL - Here is some FATAL