Java:Google App Engine“此URL不支持HTTP方法POST”错误

我刚开始玩googleappengine和Java。我过去使用过servlet,我了解它们的工作原理。我正在尝试创建一个servlet来 POST

这是我的Servlet:

public class CreateUser extends HttpServlet
{
    private static final long serialVersionUID = 1L;

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException
    {
        ...
    }
}

以下是我从一个表单发布到这里时得到的信息:

HTTP ERROR 405
Problem accessing /user/create. Reason:
HTTP method POST is not supported by this URL

<web-app...>
    ...
    <servlet>
        <servlet-name>CreateUser</servlet-name>
        <servlet-class>com.joelj.music.api.CreateUser</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>Index</servlet-name>
        <url-pattern>/user/create</url-pattern>
    </servlet-mapping>
</web-app>

谢谢。