问题
I am getting this "HTTP method POST is not supported by this URL" error when I run my project. The funny thing is, it was running perfectly fine two days ago. After I made a few changes to my code but then restored my original code and its giving me this error. Could you please help me?
Here is my index.html:
<form method="post" action="login.do">
<div>
<table>
<tr><td>Username: </td><td><input type="text" name="e_name"/>
</td> </tr>
<tr><td> Password: </td><td><input type="password" name="e_pass"/>
</td> </tr>
<tr><td></td><td><input type="submit" name ="e_submit" value="Submit"/>
Here is my Login servlet:
public class Login extends HttpServlet {
/**
* Processes requests for both HTTP
* <code>GET</code> and
* <code>POST</code> methods.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException, SQLException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
try {
/*
* TODO output your page here. You may use following sample code.
*/
int status;
String submit = request.getParameter("e_submit");
String submit2 = request.getParameter("a_submit");
out.println("Here1");
String e_name = request.getParameter("e_name");
String e_password = request.getParameter("e_pass");
String a_name = request.getParameter("a_name");
String a_password = request.getParameter("a_pass");
out.println(e_name+e_password+a_name+a_password);
Author author = new Author(a_name,a_password);
Editor editor = new Editor(e_name,e_password);
// If it is an AUTHOR login:
if(submit==null){
status = author.login(author);
out.println("Author Login");
//Incorrect login details
if(status==0) {
out.println("Incorrect");
RequestDispatcher view = request.getRequestDispatcher("index_F.html");
view.forward(request, response);
}
//Correct login details --- AUTHOR
else {
out.println("Correct login details");
HttpSession session = request.getSession();
session.setAttribute(a_name, "a_name");
RequestDispatcher view = request.getRequestDispatcher("index_S.jsp");
view.forward(request, response);
}
}
//If it is an EDITOR login
else if (submit2==null){
status = editor.login(editor);
//Incorrect login details
if(status==0) {
RequestDispatcher view = request.getRequestDispatcher("index_F.html");
view.forward(request, response);
}
//Correct login details --- EDITOR
else {
out.println("correct");
HttpSession session = request.getSession();
session.setAttribute(e_name, "e_name");
session.setAttribute(e_password, "e_pass");
RequestDispatcher view = request.getRequestDispatcher("index_S_1.html");
view.forward(request, response);
} }
out.println("</body>");
out.println("</html>");
} finally {
out.close();
}
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
super.doPost(req, resp);
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
super.doGet(req, resp);
}}
And my web.xml looks like this:
<?xml version="1.0" encoding="UTF-8"?>
<servlet>
<servlet-name>action</servlet-name>
<servlet-class>org.apache.struts.action.ActionServlet</servlet-class>
<init-param>
<param-name>config</param-name>
<param-value>/WEB-INF/struts-config.xml</param-value>
</init-param>
<init-param>
<param-name>debug</param-name>
<param-value>2</param-value>
</init-param>
<init-param>
<param-name>detail</param-name>
<param-value>2</param-value>
</init-param>
<load-on-startup>2</load-on-startup>
</servlet>
<servlet>
<servlet-name>Login</servlet-name>
<servlet-class>controller.Login</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>action</servlet-name>
<url-pattern>*.do</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>Login</servlet-name>
<url-pattern>/login.do</url-pattern>
</servlet-mapping>
<session-config>
<session-timeout>
30
</session-timeout>
</session-config>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
</welcome-file-list>
I use Glassfish v3 server - let me know anything else you need to know
回答1:
Why is there a processRequest method in your code? Who will call that method?
You can't get up to that method by calling super.doGet() or super.doPost()
you need to call that method explicitly.
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
processRequest(req,resp)
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
processRequest(req,resp)
}
EDIT
Do this
response.sendRedirect("index_F.html");
return;
instead of
RequestDispatcher view = request.getRequestDispatcher("index_F.html");
view.forward(request, response);
回答2:
That's because on your doGet() and doPost() method, you're calling it's super methods. Rather, call the processRequest() inside the respective methods mentioned above.
The super.doGet() and super.doPost() method, returns an HTTP 405, by default, so you don't call your superclass doGet() and doPost().
回答3:
Inside doPost() you have to call processRequest().
回答4:
You're calling doGet() and doPost() method without actually implementing (using super).
The HttpServlet basically follows the template method pattern where all non-overridden HTTP methods returns a HTTP 405 error "Method not supported". When you override such a method, you should not call super method, because you would otherwise still get the HTTP 405 error. The same story goes on for your doPost() method.
Call the processRequest(req,resp) inside the respective methods mentioned above.
EDIT:
Second,
Do not use dispatcher to forward request to HTML. Use redirect anyway if you want to show html only.
response.sendRedirect("index_F.html");
return;
Also, It is good practice to use redirect when you do Logout or send back for invalid credentials.
来源：https://stackoverflow.com/questions/11222695/http-status-405-http-method-post-is-not-supported-by-this-url