高分求解：servlet 405错误 求高手解释

package servlet2;

import java.io.*;

import javax.servlet.*;

import javax.servlet.http.*;

import java.util.*;

public class Show extends HttpServlet{

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

    response.setContentType("text/html");

    PrintWriter out=response.getWriter();

    String title = "Reading ALL Request Parameters";

    out.println("<BODY BGCOLOR=\"#FDF5E6\">\n"+"<H1 ALIGN=center>"+title+"</H1>\n"+"<table border=1 align=center>\n"+"<TR bgcolor=\"#FFAD00\">\n"+"<TH> Parameter Name<TH>Parameter Value(s)");

Enumeration paramNames = request.getParameterNames();

while(paramNames.hasMoreElements()){

   String paramName = (String)paramNames.nextElement();

   out.println("<TR><TD>"+paramName+"\n<TD>");

   String[] paramValues = request.getParameterValues(paramName);

   if(paramValues.length==1){

       String paramValue = paramValues[0];

       if(paramValues.length==0)

         out.println("<I>NO Value</I>");

       else

         out.println(paramValue);

   }

    else{

     out.println("<UL>");

     for(int i=0;i<paramValues.length;i++){

         out.println("<LI>"+paramValues[i]);

    }

     out.println("</UL>");

  }

}

 out.println("</table>\n</body></html>");

}

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

  doGet(request,response);

 }

}