405

jsp:
<form action="UserServlet.do?method=login" name="form1" method="Post">
web.xml:
<servlet>
  <servlet-name>UserServlet</servlet-name>
  <servlet-class>com.cms.servlet.UserServlet</servlet-class>
  </servlet>
  <servlet-mapping>
  <servlet-name>UserServlet</servlet-name>
  <url-pattern>/UserServlet.do</url-pattern>
  </servlet-mapping>
UserServlet:
protected void doPost(HttpServletResponse response,HttpServletRequest request) throws ServletException, IOException {
doGet(request,response);
}
protected void doGet(HttpServletResponse response,HttpServletRequest request) throws ServletException, IOException{
String method =(String)request.getParameter("method");....

蓝色部分只有运行时才会报错。