1 public class LoginServlet extends GenericServlet {
 2     public LoginServlet() {
 3     }
 4
 5     public void init() {
 6         System.out.println("init....");
 7     }
 8
 9     public void service(ServletRequest request, ServletResponse response) throws ServletException, IOException {
10         // 即使我们继承了GenericServlet,我们还是有些操作不太方便。
11         // 比如：获取请求方法
12         HttpServletRequest req = (HttpServletRequest) request;
13         String requestMethod = req.getMethod();
14     }
15 }

 1 package com.dx.hiservlet;
 2
 3 import java.io.IOException;
 4
 5 import javax.servlet.ServletException;
 6 import javax.servlet.ServletRequest;
 7 import javax.servlet.ServletResponse;
 8 import javax.servlet.http.HttpServletRequest;
 9 import javax.servlet.http.HttpServletResponse;
10
11 /**
12  * 针对HTPP协议定义的一个Servlet
13  * */
14 public class MyHttpServlet extends MyGenericServlet{
15
16     public MyHttpServlet() {
17         // TODO Auto-generated constructor stub
18     }
19
20     @Override
21     public void service(ServletRequest arg0, ServletResponse arg1)
22             throws ServletException, IOException {
23         if(arg0 instanceof HttpServletRequest){
24             HttpServletRequest request=(HttpServletRequest)arg0;
25             if(arg0 instanceof HttpServletResponse){
26                 HttpServletResponse response=(HttpServletResponse)arg1;
27
28                 service(request,response);
29             }
30         }
31     }
32
33     public void service(HttpServletRequest request,HttpServletResponse response)
34             throws ServletException, IOException {
35         // 1. 获取请求方式。
36         String method= request.getMethod();
37
38         // 2.根据请求方式，调用相应处理方法。
39         if(method.toUpperCase().equals("GET")){
40             doGet(request,response);
41         }else if(method.toUpperCase().equals("POST")){
42             doPost(request,response);
43         }
44         // ...
45     }
46
47     public void doGet(HttpServletRequest request, HttpServletResponse response)
48             throws ServletException, IOException {
49
50     }
51
52     public void doPost(HttpServletRequest request, HttpServletResponse response)
53             throws ServletException, IOException {
54         // TODO Auto-generated method stub
55
56     }
57
58
59 }

package com.dx.hiservlet;import java.io.IOException;import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;public class LoginServlet2 extends MyHttpServlet{public LoginServlet2() {// TODO Auto-generated constructor stub
    }@Overridepublic void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {    String method = request.getMethod();}@Overridepublic void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {}}