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。
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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" );
}
}
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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。
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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" );
}
}
}
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三、登录成功时的视图层
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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();
}
}
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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服务器之家。
原文链接:http://blog.csdn.net/chendongqaq/article/details/78298938