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：

 

Request URL:
 
http://localhost:8080/web/SessionTest
Request Method:
 

GET

Status Code:
 
302 Found

Request Headersview source

Accept:
 

text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8

Accept-Encoding:
 

gzip,deflate,sdch

Accept-Language:
 

en-US,en;q=0.8,zh;q=0.6,ko;q=0.4,ja;q=0.2

Cache-Control:
 

max-age=0

Connection:
 

keep-alive

Host:
 

localhost:8080

User-Agent:
 

Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.94 Safari/537.36

Response Headersview source

Content-Length:
 

0

Content-Type:
 

text/html;charset=UTF-8

Date:
 

Thu, 06 Jun 2013 07:16:55 GMT

Location:
 
http://localhost:8080/web/
Server:
 

Apache-Coyote/1.1

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

Request URL:
 
http://localhost:8080/web/SessionTest
Request Method:
 

GET

Status Code:
  

200 OK

Request Headersview source

Accept:
 

text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8

Accept-Encoding:
 

gzip,deflate,sdch

Accept-Language:
 

en-US,en;q=0.8,zh;q=0.6,ko;q=0.4,ja;q=0.2

Connection:
 

keep-alive

Cookie:
 

JSESSIONID=4D4C34D45462707E53A475C060E2D2A2; test=test

DNT:
 

1

Host:
 

localhost:8080

User-Agent:
 

Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.94 Safari/537.36

Response Headersview source

Content-Length:
 

218

Content-Type:
 

text/html;charset=UTF-8

Date:
 

Thu, 06 Jun 2013 09:12:04 GMT

Server:
 

Apache-Coyote/1.1

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：

 

 

Request URL:
 
http://localhost:8080/web/SessionTest
Request Method:
 

GET

Status Code:
 
200 OK

Request Headersview source

Accept:
 

text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8

Accept-Encoding:
 

gzip,deflate,sdch

Accept-Language:
 

en-US,en;q=0.8,zh;q=0.6,ko;q=0.4,ja;q=0.2

Cache-Control:
 

max-age=0

Connection:
 

keep-alive

Cookie:
 

JSESSIONID=FB43328EF48C78B7122454F84B57F164

DNT:
 

1

Host:
 

localhost:8080

User-Agent:
 

Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.94 Safari/537.36

Response Headersview source

Content-Length:
 

186

Content-Type:
 

text/html;charset=UTF-8

Date:
 

Thu, 06 Jun 2013 07:47:13 GMT

Server:
 

Apache-Coyote/1.1

Set-Cookie:
 

JSESSIONID=BC3FDA2D942F2F4B50757D9C436D21A9; Path=/web/; HttpOnly

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。