1、
这个问题困扰我一小天，于使用ecliplse构建maven项目所以加完jar包对应的依赖后没有maven-clean和maven-test,所以很多问题出了都不知道，后来在一个帖子里看到解决问题办法。使用maven-test检查jar包是否有问题，一检查真是我的jar包冲突，有jar包依赖加重了删除之后问题消失。

2、Apache的log4j.jar包有问题改成log4j.jar既好。

3、.java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/myBatis-PageHelper]]
at java.util.concurrent.FutureTask.report(FutureTask.java:122)
at java.util.concurrent.FutureTask.get(FutureTask.java:188)
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:945)
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:871)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)
at org.apache.catalina.core.ContainerBase $StartChild.call(ContainerBase.java:1410) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1400)
at java.util.concurrent.FutureTask.run(FutureTask.java:262)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/myBatis-PageHelper]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:162)
… 6 more
Caused by: java.lang.UnsupportedClassVersionError: org/springframework/web/SpringServletContainerInitializer : Unsupported major.minor version 52.0 (unable to load class org.springframework.web.SpringServletContainerInitializer)
at org.apache.catalina.loader.WebappClassLoaderBase.findClassInternal(WebappClassLoaderBase.java:2532)
at org.apache.catalina.loader.WebappClassLoaderBase.findClass(WebappClassLoaderBase.java:872)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1321)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1180)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:278)
at org.apache.catalina.startup.WebappServiceLoader.loadServices(WebappServiceLoader.java:186)

这个问题把spring的jar包版本改一下我之前用的5.1.2.release改成4.1.4.release成功