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java web实现自动登录功能

程序员文章站 2024-02-21 21:35:40
本文实例为大家分享了java web实现自动登录功能的具体代码，供大家参考，具体内容如下 主要思路就是：当用户访问网站的首页时，浏览器端会先检擦浏览器中存在的cookie...

本文实例为大家分享了java web实现自动登录功能的具体代码，供大家参考，具体内容如下

主要思路就是：当用户访问网站的首页时，浏览器端会先检擦浏览器中存在的cookie中是否又登录的用户的用户名，如果有，则直接跳转至用户登录好的界面，如果没有，则重定向至登录界面，在服务器端创建该用户登录的cookie,响应时，将创建的cookie返回至浏览器端保存。

一、用户访问首页时检查cookie是否存在。

package ahpudong.com;

import java.io.ioexception;
import java.io.printwriter;
import javax.servlet.servletexception;
import javax.servlet.annotation.webservlet;
import javax.servlet.http.cookie;
import javax.servlet.http.httpservlet;
import javax.servlet.http.httpservletrequest;
import javax.servlet.http.httpservletresponse;

@webservlet("/index.do")

public class index extends httpservlet {
 public index() {
  super();
 }
 public void dopost(httpservletrequest request, httpservletresponse response)
   throws servletexception, ioexception {
  cookie[] cookies=request.getcookies();
  if(cookies!=null){
   for(cookie cookie:cookies){
    string name=cookie.getname();
    string value=cookie.getvalue();
    if("name".equals(name) && "chendong".equals(value)){
     request.setattribute(name, value);
     request.getrequestdispatcher("user.view").forward(request, response);
     return;
    }
   } 
  }
   response.sendredirect("login.jsp");
 }
}

二、确定用户登录的cookie不存在，在手动登录的过程中创建用户登录cookie。

package ahpudong.com;

import java.io.ioexception;
import java.io.printwriter;
import javax.servlet.servletexception;
import javax.servlet.annotation.webservlet;
import javax.servlet.http.cookie;
import javax.servlet.http.httpservlet;
import javax.servlet.http.httpservletrequest;
import javax.servlet.http.httpservletresponse;

@webservlet("/login.do")

public class login extends httpservlet {
 public login() {
  super();
 }
 public void dopost(httpservletrequest request, httpservletresponse response)
   throws servletexception, ioexception {
  response.setcontenttype("text/html");
  request.setcharacterencoding("utf-8");
  response.setcharacterencoding("utf-8");
  printwriter out = response.getwriter();
  string name=request.getparameter("name");
  string pwd=request.getparameter("pwd");
  string login=request.getparameter("auto");
  if("chendong".equals(name) && "123456".equals(pwd)){
   if("on".equals(login)){
    cookie cookie=new cookie("name","chendong");
    cookie.setmaxage(7*24*60*60);//有效期为一个星期
    response.addcookie(cookie);
    request.setattribute("name",name);
    request.getrequestdispatcher("user.view").forward(request, response);    
   }
  }else{
   response.sendredirect("login.jsp");
  }
 }
}

三、登录成功时的视图层

package ahpudong.com;

import java.io.ioexception;
import java.io.printwriter;

import javax.servlet.servletexception;
import javax.servlet.annotation.webservlet;
import javax.servlet.http.httpservlet;
import javax.servlet.http.httpservletrequest;
import javax.servlet.http.httpservletresponse;

@webservlet("/user.view")
public class user extends httpservlet {
 public user() {
  super();
 }
 public void doget(httpservletrequest request, httpservletresponse response)
   throws servletexception, ioexception {
  processrequest(request,response);

 }
 public void dopost(httpservletrequest request, httpservletresponse response)
   throws servletexception, ioexception {
  processrequest(request,response);
 }
 public void processrequest(httpservletrequest request,httpservletresponse response)
   throws servletexception, ioexception{
  response.setcharacterencoding("utf-8");
  printwriter out=response.getwriter();
  string name=(string) request.getattribute("name");
  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>");
  out.println("<h1>"+"welcome "+name+" login"+"</h1>");
  out.println(" </body>");
  out.println("</html>");
  out.flush();
  out.close(); 
 }
}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。

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