java web实现自动登录功能
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2024-04-01 23:50:28
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。