springmvc報錯 org.springframework.web.servlet.DispatcherServlet

在寫springMVC時，導入全部須要的包後，運行程序，控制檯報如下錯誤：

嚴重: Servlet [springDispatcherServlet] in web application [/SpringMVC-1] threw load() exception
java.lang.ClassNotFoundException: org.springframework.web.servlet.DispatcherServlet
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1333)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1167)
at org.apache.catalina.core.DefaultInstanceManager.loadClass(DefaultInstanceManager.java:518)
at org.apache.catalina.core.DefaultInstanceManager.loadClassMaybePrivileged(DefaultInstanceManager.java:499)
at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:118)
at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1091)
at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1027)
at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:5038)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5348)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:725)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:701)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:717)
at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:587)
at org.apache.catalina.startup.HostConfig$DeployDescriptor.run(HostConfig.java:1798)
at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)

隨便在一個java文件中都沒法import org.springframework.web.servlet.DispatcherServlet，這個類主要是在spring-webmvc jar包下，全部導入的jar包以下：

都已經導入，沒有問題。可是實際上還要把依賴都加進classpath下。步驟：

項目右擊-->properties-->Deployment Assembly-->add-->Java Build Path Entries-->導入全部依賴的Jar包，從新start tomcat便可。