Tomcat 7 Start up problem in Eclispse for maven project

I m getting this intermittent problem in eclipse, when i try to run a maven project in tomcat

Details are as follows :

• Eclipse version : 3.6
• Maven version : 2.2.1
• Tomcat version : 7

Error log :

java.lang.ClassNotFoundException: org.springframework.web.context.ContextLoaderListener
 at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1362)
 at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1208)
 at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:3712)
 at org.apache.catalina.core.StandardContext.start(StandardContext.java:4216)
 at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1014)
 at org.apache.catalina.core.StandardHost.start(StandardHost.java:736)
 at org.apa开发者_JS百科che.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(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:295)
 at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:433)

Deleting and Recreating the server solves the problem, but still i would like to know why this error is created.

This error usually occurs when Spring misses a jar file on the classpath. The main reason for this is that Eclipse not always deploys a project correctly to its Tomcat server. Instead of deleting the server, you can also clean the server and redeploy the application.

Thanks for your reply. Well my problem was fixed by doing a mvn eclipse:clean eclipse:eclipse

I encountered the same error

I added my spring library in deployment assembly and build path of the project.

I think your server did not detect the library and restarting it made the server check for the build paths.