log4j文件怎么写，放在程序的什么位置

Question

程序出了这样一个错误，程序没有log4j的文件。这个文件怎么写。具体要求，要放在什么位置。求高手指点，感激
log4j:ERROR setFile(null,true) call failed.
java.io.FileNotFoundException: SampleMessages.log4j (拒绝访问。)
at java.io.FileOutputStream.openAppend(Native Method)
at java.io.FileOutputStream.<init>(FileOutputStream.java:177)
at java.io.FileOutputStream.<init>(FileOutputStream.java:102)
at org.apache.log4j.FileAppender.setFile(FileAppender.java:290)
at org.apache.log4j.FileAppender.activateOptions(FileAppender.java:164)
at org.apache.log4j.DailyRollingFileAppender.activateOptions(DailyRollingFileAppender.java:216)
at org.apache.log4j.config.PropertySetter.activate(PropertySetter.java:257)
at org.apache.log4j.config.PropertySetter.setProperties(PropertySetter.java:133)
at org.apache.log4j.config.PropertySetter.setProperties(PropertySetter.java:97)
at org.apache.log4j.PropertyConfigurator.parseAppender(PropertyConfigurator.java:689)
at org.apache.log4j.PropertyConfigurator.parseCategory(PropertyConfigurator.java:647)
at org.apache.log4j.PropertyConfigurator.configureRootCategory(PropertyConfigurator.java:544)
at org.apache.log4j.PropertyConfigurator.doConfigure(PropertyConfigurator.java:440)
at org.apache.log4j.PropertyConfigurator.doConfigure(PropertyConfigurator.java:476)
at org.apache.log4j.helpers.OptionConverter.selectAndConfigure(OptionConverter.java:471)
at org.apache.log4j.LogManager.<clinit>(LogManager.java:125)
at org.apache.log4j.Logger.getLogger(Logger.java:105)
at org.apache.commons.logging.impl.Log4JLogger.getLogger(Log4JLogger.java:289)
at org.apache.commons.logging.impl.Log4JLogger.<init>(Log4JLogger.java:109)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at org.apache.commons.logging.impl.LogFactoryImpl.createLogFromClass(LogFactoryImpl.java:1116)
at org.apache.commons.logging.impl.LogFactoryImpl.discoverLogImplementation(LogFactoryImpl.java:914)
at org.apache.commons.logging.impl.LogFactoryImpl.newInstance(LogFactoryImpl.java:604)
at org.apache.commons.logging.impl.LogFactoryImpl.getInstance(LogFactoryImpl.java:336)
at org.apache.commons.logging.impl.LogFactoryImpl.getInstance(LogFactoryImpl.java:310)
at org.apache.commons.logging.LogFactory.getLog(LogFactory.java:685)
at org.springframework.web.context.ContextLoader.<clinit>(ContextLoader.java:146)
at org.springframework.web.context.ContextLoaderListener.createContextLoader(ContextLoaderListener.java:53)
at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:44)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:3843)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4342)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:791)
at org.apache.catalina.core.ContainerBase.access$000(ContainerBase.java:123)
at org.apache.catalina.core.ContainerBase$PrivilegedAddChild.run(ContainerBase.java:145)
at java.security.AccessController.doPrivileged(Native Method)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:769)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:525)
at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:926)
at org.apache.catalina.startup.HostConfig.deployDirectories(HostConfig.java:889)
at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:492)
at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1149)
at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:311)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1053)
at org.apache.catalina.core.StandardHost.start(StandardHost.java:719)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045)
at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:443)
at org.apache.catalina.core.StandardService.start(StandardService.java:516)
at org.apache.catalina.core.StandardServer.start(StandardServer.java:710)
at org.apache.catalina.startup.Catalina.start(Catalina.java:578)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:288)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:413)
log4j:ERROR Either File or DatePattern options are not set for appender [A1].

Answer 1

log4j.properties  放在src下
内容：
#Created by cyf
log4j.appender.file=org.apache.log4j.FileAppender
log4j.appender.file.File=accp.log
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=%d{yyyy/MM/dd-HH\:mm\:ss} %5p %c{1}\:%L - %m%n
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{yyyy/MM/dd-HH\:mm\:ss} %5p %c{1}\:%L - %m%n
log4j.rootLogger=info,stdout

Answer 2

log4j的文件随便到网上找个现成的就行了,然后放在src下面
再根据自己的项目需要去改动,这些用google都比较翻便查到的