request对象和response对象(5)

p>    }

p>    

p>    //刷到别的页面

p>    private void test2(HttpServletResponse response) throws IOException{

p>        response.setContentType("text/html;charset=UTF-8");

p>        PrintWriter out = response.getWriter();

p>        response.setHeader("Refresh", "2;URL=/Response/index.jsp");

p>        out.write("登陆成功！2秒后将跳转到主页！若没有跳转，请猛点<a href='/Response/index.jsp'>这里</a>");

p>    }

p>    

p>    public void doPost(HttpServletRequest request, HttpServletResponse response)

p>            throws ServletException, IOException {

p>        doGet(request,response);

p>    }

p>}

p>复制代码

p>5.控制缓存时间

p> 

p>复制代码

p>package cn.lsl.response;

p> 

p> 

p> 

p>import java.io.IOException;

p> 

p>import javax.servlet.ServletException;

p> 

p>import javax.servlet.http.HttpServlet;

p> 

p>import javax.servlet.http.HttpServletRequest;

p> 

p>import javax.servlet.http.HttpServletResponse;

p> 

p> 

p> 

p>public class ResponseDemo5 extends HttpServlet {

p> 

p> 

p> 

p>    public void doGet(HttpServletRequest request, HttpServletResponse response)

p> 

p>           throws ServletException, IOException {

p> 

p>       //缓存一小时

p> 

p>       response.setDateHeader("Expires", System.currentTimeMillis()+60*60*1000);

p> 

p>       response.getWriter().write("hello");

p> 

p>    }

p> 

p> 

p> 

p>    public void doPost(HttpServletRequest request, HttpServletResponse response)

p> 

p>           throws ServletException, IOException {

p> 

p>       doGet(request,response);

p> 

p>    }

p> 

p>}

p>复制代码

p>6.请求重定向

p> 

p>请求重定向：一个web资源收到客户端请求后，通知客户端去访问另外一个web资源，这称之         为请求重定向。

p> 

p>地址栏会连，并发送2次请求，增加服务器负担。

p> 

p>实现方式：response.sendRedirect();

p> 

p>原理：302/307状态码和location头即可实现重定向

p> 

p>复制代码

p>package cn.lsl.response;

p>import java.io.IOException;

p>import javax.servlet.ServletException;

p>import javax.servlet.http.HttpServlet;

p>import javax.servlet.http.HttpServletRequest;

p>import javax.servlet.http.HttpServletResponse;

p> 

p>public class ResponseDemo6 extends HttpServlet {