帮忙排一下这个500错误

Question

type Exception reportmessage description The server encountered an internal error () that prevented it from fulfilling this request.exception javax.servlet.ServletException: Class servlet.RegisterServlet is not a Servlet
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:849)
org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:454)
java.lang.Thread.run(Unknown Source)
root cause java.lang.ClassCastException: servlet.RegisterServlet
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:849)
org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:454)
java.lang.Thread.run(Unknown Source)
note The full stack trace of the root cause is available in the Apache Tomcat/6.0.20 logs.

Answer 1

RegisterServlet 这个类不是一个Server ,你是不是没有继承HttpServlet类啊

Answer 2

现在我继承了  但是现在部署都不能成功了我的servlet是这样写的  您看一下对吗~！！
package servlet;
import java.io.IOException;
import java.util.ArrayList;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import bean.User;
import db.DB;
public class RegisterServlet extends HttpServlet{
public void doGet(HttpServletRequest request,HttpServletResponse response)throws ServletException,IOException{
//设置请求编码
request.setCharacterEncoding("gb2312");
//设置响应编码
response.setContentType("gb2312");
//获得jsp页面的输入的用户名的值
String username=request.getParameter("username");
//获得jsp页面的输入的密码
String pwd=request.getParameter("pwd");
//测试
//System.out.println(username+" "+pwd);



if(new DB().inserUser(username, pwd)){
response.sendRedirect("login.jsp");
}

}
public void doPost(HttpServletRequest request,HttpServletResponse response)throws ServletException,IOException{
doGet(request,response);

}

}
我的web.xml是这样的 <?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" 
xmlns="http://java.sun.com/xml/ns/javaee" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
  <servlet>
      <servlet-name>registerServlet</servlet-name>
      <servlet-class>servlet.RegisterServlet</servlet-class>
  </servlet>  <servlet-mapping>
      <servlet-name>registerServlet</servlet-name>
      <url-pattern>/registerServlet</url-pattern>
  </servlet-mapping>
</web-app>