log4j.properties配置如下：
[code="java"]# Set root logger level to WARN and append to stdout
log4j.rootLogger=INFO, stdout, appender1
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
Pattern to output the caller's file name and line number.
log4j.appender.stdout.layout.ConversionPattern=%d %5p (%c:%L) - %m%n
Print only messages of level ERROR or above in the package noModule.
log4j.logger.noModule=FATAL
OpenSymphony Stuff
log4j.logger.com.opensymphony=INFO
log4j.logger.org.apache.struts2=INFO
Spring Stuff
log4j.logger.org.springframework=INFO
log4j.appender.appender1=org.apache.log4j.FileAppender
log4j.appender.appender1.File=c:/Log4JDemo02.log
log4j.appender.appender1.layout=org.apache.log4j.TTCCLayout[/code]
对应java程序如下：
[code="java"]public class Log4jInit extends HttpServlet {
public void init() {
String prefix = getServletContext().getRealPath("/");
String file = getInitParameter("log4j");
if(file != null) {
PropertyConfigurator.configure(prefix+file);
}
}
} [/code]
在服务器启动时出现以下错误信息：
[code="java"]log4j:ERROR setFile(null,true) call failed.
java.io.FileNotFoundException: c:\Log4JDemo02.log (Access is denied)
at java.io.FileOutputStream.openAppend(Native Method)
at java.io.FileOutputStream.(Unknown Source)
at java.io.FileOutputStream.(Unknown Source)
at org.apache.log4j.FileAppender.setFile(FileAppender.java:273)
at org.apache.log4j.FileAppender.activateOptions(FileAppender.java:152)
at org.apache.log4j.config.PropertySetter.activate(PropertySetter.java:247)
at org.apache.log4j.config.PropertySetter.setProperties(PropertySetter.java:123)
at org.apache.log4j.config.PropertySetter.setProperties(PropertySetter.java:87)
at org.apache.log4j.PropertyConfigurator.parseAppender(PropertyConfigurator.java:645)
at org.apache.log4j.PropertyConfigurator.parseCategory(PropertyConfigurator.java:603)
at org.apache.log4j.PropertyConfigurator.configureRootCategory(PropertyConfigurator.java:500)
at org.apache.log4j.PropertyConfigurator.doConfigure(PropertyConfigurator.java:406)
at org.apache.log4j.PropertyConfigurator.doConfigure(PropertyConfigurator.java:307)
at org.apache.log4j.PropertyConfigurator.configure(PropertyConfigurator.java:315)
at com.bugu.web.init.Log4jInit.init(Log4jInit.java:16)
at javax.servlet.GenericServlet.init(GenericServlet.java:212)
at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1139)
at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:966)
at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:3956)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4230)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1014)
at org.apache.catalina.core.StandardHost.start(StandardHost.java:736)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1014)
at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:443)
at org.apache.catalina.core.StandardService.start(StandardService.java:448)
at org.apache.catalina.core.StandardServer.start(StandardServer.java:700)
at org.apache.catalina.startup.Catalina.start(Catalina.java:552)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:295)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:433)[/code]
发生错误的地方是：PropertyConfigurator.configure(prefix+file)
