控制台文件：
严重: Allocate exception for servlet SaveCustomer
java.lang.ClassNotFoundException: servlet.SaveCustomer
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1702)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1547)
at org.apache.catalina.core.DefaultInstanceManager.loadClass(DefaultInstanceManager.java:532)
at org.apache.catalina.core.DefaultInstanceManager.loadClassMaybePrivileged(DefaultInstanceManager.java:514)
at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:142)
at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1144)
at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:865)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:136)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1041)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:603)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:748)
浏览器页面：
type Exception report
message Error instantiating servlet class servlet.SaveCustomer
description The server encountered an internal error that prevented it from fulfilling this request.
exception
javax.servlet.ServletException: Error instantiating servlet class servlet.SaveCustomer
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1041)
org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:603)
org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
java.lang.Thread.run(Thread.java:748)
root cause
java.lang.ClassNotFoundException: servlet.SaveCustomer
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1702)
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1547)
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1041)
org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:603)
org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
java.lang.Thread.run(Thread.java:748)
note The full stack trace of the root cause is available in the Apache Tomcat/7.0.47 logs.
Apache Tomcat/7.0.47
servlet.SaveCustomer类找不到
1·核对名称是否正确
2·检查是否正确编译发布到项目目录下，project/WEB-INF/classes
你检查一下你的web.xml里有没有配置servlet,
Servlet的名称（自己起的，不要重复）
Servlet的类路径（xx.xx.xx.xxservlet）
Servlet的名称（与上面的一样）
/url名字（自己起的，不要重复，注意/，不能丢）
<servlet>
<servlet-name>Servlet的名称（自己起的，不要重复）</servlet-name>
<servlet-class>Servlet的类路径（xx.xx.xx.xxservlet）</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>Servlet的名称（与上面的一样）</servlet-name>
<url-pattern>/url名字（自己起的，不要重复，注意/，不能丢）</url-pattern>
</servlet-mapping>
java.lang.ClassNotFoundException: servlet.SaveCustomer
类找不到异常 ，后面接的是找不到的类