servlet redirect/forward/session/cookie 与 HTTP 协议的测试

 本文直接展示servlet的测试结果。

 

servlet的代码中使用sendRedirect：

  

public class SessionTest extends HttpServlet {    protected void processRequest(HttpServletRequest request, HttpServletResponse response)            throws ServletException, IOException {...response.sendRedirect("http://localhost:8080/web/");...}

 

 

查看浏览器交互过程，先是请求该servlet：

 

1. Request URL:
    
   http://localhost:8080/web/SessionTest
2. Request Method:
    
   GET
3. Status Code:
    
   302 Found
4. Request Headersview source
   1. Accept:
       
      text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
   2. Accept-Encoding:
       
      gzip,deflate,sdch
   3. Accept-Language:
       
      en-US,en;q=0.8,zh;q=0.6,ko;q=0.4,ja;q=0.2
   4. Cache-Control:
       
      max-age=0
   5. Connection:
       
      keep-alive
   6. Host:
       
      localhost:8080
   7. User-Agent:
       
      Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.94 Safari/537.36
5. Response Headersview source
   1. Content-Length:
       
      0
   2. Content-Type:
       
      text/html;charset=UTF-8
   3. Date:
       
      Thu, 06 Jun 2013 07:16:55 GMT
   4. Location:
       
      http://localhost:8080/web/
   5. Server:
       
      Apache-Coyote/1.1
   6. Set-Cookie:
       
      JSESSIONID=8C8DCD7355CC62C75C9BD154B2ADEDD0; Path=/web/; HttpOnly

可以看到response返回了302，并带上了location, 指示浏览器做第二次跳转请求，浏览器得到提示后进行第二次请求。

 

同样的servlet，将代码改为forward，实现了在servlet容器内部的跳转，对浏览器实际上是不可见得。

 

request.getRequestDispatcher("/index.jsp").forward(request, response);

 

看一下tomcat服务器的响应，一个200  OK之后，直接返回了内容，很直接

1. Request URL:
    
   http://localhost:8080/web/SessionTest
2. Request Method:
    
   GET
3. Status Code:
     
   200 OK
4. Request Headersview source
   1. Accept:
       
      text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
   2. Accept-Encoding:
       
      gzip,deflate,sdch
   3. Accept-Language:
       
      en-US,en;q=0.8,zh;q=0.6,ko;q=0.4,ja;q=0.2
   4. Connection:
       
      keep-alive
   5. Cookie:
       
      JSESSIONID=4D4C34D45462707E53A475C060E2D2A2; test=test
   6. DNT:
       
      1
   7. Host:
       
      localhost:8080
   8. User-Agent:
       
      Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.94 Safari/537.36
5. Response Headersview source
   1. Content-Length:
       
      218
   2. Content-Type:
       
      text/html;charset=UTF-8
   3. Date:
       
      Thu, 06 Jun 2013 09:12:04 GMT
   4. Server:
       
      Apache-Coyote/1.1
   5. Set-Cookie:
       
      JSESSIONID=0FE64A4D2D1777BD44F08F2F8186384B; Path=/web/; HttpOnly

 

再看cookie的保存，将以上代码改为将cookie加入response：

 

        Cookie cookie = new Cookie("test","test");        response.addCookie(cookie);        PrintWriter out = response.getWriter();

 

 

再看HTTP head：

 

 

1. Request URL:
    
   http://localhost:8080/web/SessionTest
2. Request Method:
    
   GET
3. Status Code:
    
   200 OK
4. Request Headersview source
   1. Accept:
       
      text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
   2. Accept-Encoding:
       
      gzip,deflate,sdch
   3. Accept-Language:
       
      en-US,en;q=0.8,zh;q=0.6,ko;q=0.4,ja;q=0.2
   4. Cache-Control:
       
      max-age=0
   5. Connection:
       
      keep-alive
   6. Cookie:
       
      JSESSIONID=FB43328EF48C78B7122454F84B57F164
   7. DNT:
       
      1
   8. Host:
       
      localhost:8080
   9. User-Agent:
       
      Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.94 Safari/537.36
5. Response Headersview source
   1. Content-Length:
       
      186
   2. Content-Type:
       
      text/html;charset=UTF-8
   3. Date:
       
      Thu, 06 Jun 2013 07:47:13 GMT
   4. Server:
       
      Apache-Coyote/1.1
   5. Set-Cookie:
       
      JSESSIONID=BC3FDA2D942F2F4B50757D9C436D21A9; Path=/web/; HttpOnly
   6. Set-Cookie:
       
      test=test

Tomcat通过HTTP协议的Set-Cookie将servlet的cookie放入了响应头，查看浏览器的cookie，除了jsessionid，又加了一个test/test的cookie进来。