HTTP Status 500

Question

HTTP Status 500 - Error instantiating servlet class com.imooc.servlet.SmartDownloadServlet

---

type Exception report

message Error instantiating servlet class com.imooc.servlet.SmartDownloadServlet

description The server encountered an internal error that prevented it from fulfilling this request.

exception

javax.servlet.ServletException: Error instantiating servlet class com.imooc.servlet.SmartDownloadServlet
	org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
	org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
	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:1023)
	org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
	org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:1852)
	java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	java.lang.Thread.run(Thread.java:745)

 

root cause

java.lang.ClassNotFoundException: com.imooc.servlet.SmartDownloadServlet
	org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1714)
	org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1559)
	org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
	org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
	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:1023)
	org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
	org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:1852)
	java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	java.lang.Thread.run(Thread.java:745)

 

note The full stack trace of the root cause is available in the Apache Tomcat/7.0.42 logs

 

Answer 1

错误是没有找到com.imooc.servlet.SmartDownloadServletz这个类

Answer 2

java代码有错误