HTTP method GET is not supported by this URL
几天做servlet发现了个问题，Google了下就解决了，还是记下来：
Servlet eroor：HTTP method GET is not supported by this URL
错误提示：
type: Status report
message: HTTP method GET is not supported by this URL
description: The specified HTTP method is not allowed for the requested resource (HTTP method GET is not supported by this URL).
原因：
1，继承自HttpServlet的Servlet没有重写对于请求和响应的处理方法：doGet或doPost等方法；默认调用父类的doGet或doPost等方法；
2，父类HttpServlet的doGet或doPost等方法覆盖了你重写的doGet或doPost等方法；
不管是1或2，父类HttpServlet的doGet或doPost等方法的默认实现是返回状态代码为405的HTTP错误表示对于指定资源的请求方法不被允许。
解决方法：
1，子类重写doGet或doPost等方法；
2，在你扩展的Servlert中重写doGet或doPost等方法来处理请求和响应时 不要调用父类HttpServlet的doGet或doPost等方法，即去掉super.doGet(request, response)和super.doPost(request, response);
web.config的配置
<servlet>
<servlet-name>com.panjun.servlets.HelloWorld</servlet-name>
<servlet-class>com.panjun.servlets.HelloWorld</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>com.panjun.servlets.HelloWorld</servlet-name>
<url-pattern>/HelloWorld</url-pattern>
</servlet-mapping>
package com.panjun.servlets;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class HelloWorld extends HttpServlet {
/* (non-Javadoc)
* @see javax.servlet.http.HttpServlet#doGet(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
*/
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
// TODO Auto-generated method stub
//super.doGet(req, resp);
resp.setContentType("text/html");
PrintWriter out = resp.getWriter();
out.println("<HTML>");
out.println("<HEAD><TITLE>Hello World</TITLE></HEAD>");
out.println("<BODY>");
out.println("<BIG>Hello World</BIG>");
out.println("</BODY></HTML>");
}
public void doPost(HttpServletRequest req, HttpServletResponse res)
throws ServletException, IOException {
doGet(req, res);
}
}