会话跟踪机制 Session
程序员文章站
2022-03-15 11:04:11
...
package com.oracle.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;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
public class LoginServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doPost(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//获得用户名和密码
String userName=request.getParameter("userName");
String password=request.getParameter("password");
if(userName.equals(password)){
//将用户名和密码保存在session中
HttpSession session=request.getSession();
session.setAttribute("userName", userName);
session.setAttribute("password", password);
//超时时间为30秒
//session.setMaxInactiveInterval(30);
Cookie c=new Cookie("username",userName);
//写在文件夹下
c.setMaxAge(90*24*60*60);
response.addCookie(c);
response.sendRedirect("listmail.html");
}else{
response.sendRedirect("first.html");
}
}
}
package com.oracle.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;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
public class MailServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doPost(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//判断用户是否登录，如没登陆，重定向到登陆页
HttpSession session=request.getSession();
Cookie[] cc=request.getCookies();
for(Cookie c:cc){
System.out.println(c.getName()+":"+c.getValue());
if(c.getName().equals("userName")){
System.out.println("用户名是："+c.getName());
}
}
System.out.println(session.getId());
String name=(String)session.getAttribute("userName");
if(name!=null){
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
out.println(" <BODY>");
String flag=request.getParameter("flag");
if(flag.equals("1")){
out.println(name+"发送邮件成功");
}else if(flag.equals("2")){
out.println(name+"删除了邮件");
}else if(flag.equals("3")){
out.println(name+"有n封未读邮件");
}else{
session.invalidate();
out.println("用户已注销");
}
out.println("</BODY>");
out.println("</HTML>");
out.flush();
out.close();
}else{
response.sendRedirect("first.html");
}
}
}
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>MyHtml.html</title>
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="this is my page">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<!--<link rel="stylesheet" type="text/css" href="./styles.css">-->
</head>
<body>
This is my HTML page. <br>
<form method="post" action="login">
userName:<input type="text" name="userName"/><br/>
password:<input type="text" name="password"/><br/>
<input type="submit" value="登陆"/>
</form>
</body>
</html>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>listmail.html</title>
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="this is my page">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<!--<link rel="stylesheet" type="text/css" href="./styles.css">-->
</head>
<body>
This is my beatiful page. <br>
<ul>
<li><a href="mail?flag=1">发送邮件</a></li>
<li><a href="mail?flag=2">删除邮件</a></li>
<li><a href="mail?flag=3">查找邮件</a></li>
<li><a href="mail?flag=4">注销用户</a></li>
</ul>
</body>
</html>
<servlet-mapping>
<servlet-name>LoginServlet</servlet-name>
<url-pattern>/login</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>MailServlet</servlet-name>
<url-pattern>/mail</url-pattern>
</servlet-mapping>