本博客介绍了一个Servlet实例，展示了如何通过Cookie追踪用户的登录次数，并在页面上动态显示登录信息。通过GET请求获取Cookie信息，对于已登录用户增加登录次数并更新Cookie；对于首次访问的用户设置初始登录次数为1。
package com.csdn.servlet;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
importjavax.servlet.http.HttpServletResponse;
public class TestS extends HttpServlet {
/**
* Constructor of theobject.
*/
public TestS() {
super();
}
/**
* Destruction of the servlet.<br>
*/
public void destroy() {
super.destroy(); // Justputs "destroy" string in log
// Put your code here
}
/**
* The doGet method of the servlet.<br>
*
* This method is calledwhen a form has its tag value method equals to get.
*
* @param request
* the request send by the client tothe server
* @param response
* the response send by the server tothe client
* @throws ServletException
* if an error occurred
* @throws IOException
* if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponseresponse)
throws ServletException, IOException {
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();
out
.println("<!DOCTYPEHTML PUBLIC \"-//W3C//DTDHTML 4.01 Transitional//EN\">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>AServlet</TITLE></HEAD>");
out.println(" <BODY>");
Cookie cookie = null;
Cookie[] cookies = request.getCookies();
if (null != cookies) {
for (int i = 0; i < cookies.length; i++) {
cookie = cookies[i];
if ("loginCount".equals(cookie.getName())) {
int count = Integer.parseInt(cookie.getValue()) + 1;
cookie.setValue(count + "");
response.addCookie(cookie);
out.println("你是第" + count + "次登录");
break;
}
}
} else {
cookie = new Cookie("loginCount", "1");
cookie.setMaxAge(60 * 60 * 24);
response.addCookie(cookie);
out.println("你好！你是第1次登录我们的网站");
}
out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
}
/**
* The doPost method of theservlet. <br>
*
* This method is calledwhen a form has its tag value method equals to
* post.
*
* @param request
* the request send by the client tothe server
* @param response
* the response send by the server tothe client
* @throws ServletException
* if an error occurred
* @throws IOException
* if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponseresponse)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out
.println("<!DOCTYPEHTML PUBLIC \"-//W3C//DTDHTML 4.01 Transitional//EN\">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>AServlet</TITLE></HEAD>");
out.println(" <BODY>");
out.print(" This is ");
out.print(this.getClass());
out.println(", using thePOST method");
out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
}
/**
* Initialization of the servlet.<br>
*
* @throws ServletException
* if an error occurs
*/
public void init() throws ServletException {
// Put your code here
}
}
扫一扫
3395
被折叠的 条评论
为什么被折叠?
到【灌水乐园】发言
