配置log4j和slf4j爬过的坑

问题描述：

这两天负责人要求代码中的日志输出需要该为log4j+slf4j格式输出，在测试demo上没有问题后，配置到项目上时，出错了，现在将错误记录一下

[WARNING] failed org.mortbay.jetty.plugin.Jetty6PluginWebAppContext@3fd05b3e{/adgame_ms,/home/hadoop/code/adgame_ms/src/main/webapp}: java.lang.NoSuchMethodError: org.slf4j.spi.LocationAwareLogger.log(Lorg/slf4j/Marker;Ljava/lang/String;ILjava/lang/String;Ljava/lang/Throwable;)V
[WARNING] failed ContextHandlerCollection@554188ac: java.lang.NoSuchMethodError: org.slf4j.spi.LocationAwareLogger.log(Lorg/slf4j/Marker;Ljava/lang/String;ILjava/lang/String;Ljava/lang/Throwable;)V
[WARNING] failed HandlerCollection@1f43cab7: java.lang.NoSuchMethodError: org.slf4j.spi.LocationAwareLogger.log(Lorg/slf4j/Marker;Ljava/lang/String;ILjava/lang/String;Ljava/lang/Throwable;)V
[ERROR] Error starting handlers
java.lang.NoSuchMethodError: org.slf4j.spi.LocationAwareLogger.log(Lorg/slf4j/Marker;Ljava/lang/String;ILjava/lang/String;Ljava/lang/Throwable;)V
	at org.apache.commons.logging.impl.SLF4JLocationAwareLog.info(SLF4JLocationAwareLog.java:159)
	at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:305)
	at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:107)
	at org.mortbay.jetty.handler.ContextHandler.startContext(ContextHandler.java:548)
	at org.mortbay.jetty.servlet.Context.startContext(Context.java:136)
	at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1250)
	at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:517)
	at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:467)
	at org.mortbay.jetty.plugin.Jetty6PluginWebAppContext.doStart(Jetty6PluginWebAppContext.java:115)
	at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
	at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection.java:152)
	at org.mortbay.jetty.handler.ContextHandlerCollection.doStart(ContextHandlerCollection.java:156)
	at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
	at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection.java:152)
	at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
	at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:130)
	at org.mortbay.jetty.Server.doStart(Server.java:224)
	at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
	at org.mortbay.jetty.plugin.Jetty6PluginServer.start(Jetty6PluginServer.java:132)
	at org.mortbay.jetty.plugin.AbstractJettyMojo.startJetty(AbstractJettyMojo.java:441)
	at org.mortbay.jetty.plugin.AbstractJettyMojo.execute(AbstractJettyMojo.java:383)
	at org.mortbay.jetty.plugin.AbstractJettyRunMojo.execute(AbstractJettyRunMojo.java:210)
	at org.mortbay.jetty.plugin.Jetty6RunMojo.execute(Jetty6RunMojo.java:184)
	at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:134)
	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:207)
	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
	at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:116)
	at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:80)
	at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51)
	at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128)
	at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:307)
	at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:193)
	at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:106)
	at org.apache.maven.cli.MavenCli.execute(MavenCli.java:863)
	at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:288)
	at org.apache.maven.cli.MavenCli.main(MavenCli.java:199)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
	at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
	at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
	at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
	at org.codehaus.classworlds.Launcher.main(Launcher.java:47)

在查阅多方博客后，找到到了答案：

查询到org.slf4j.slf4j-api-1.5.6.jar是被一个单点登录的jar依赖间接引入的，于是在父工程里面排除掉

org.slf4j.slf4j-api-1.5.6.jar间接依赖（顺便也排除掉了org.slf4j.slf4j-log4j12-1.5.6.jar这个适配器包） ，问题得到解决。

博客详情：从解决一个java.lang.NoSuchMethodError想到的