JSP实现简单的登录和注册界面详细全过程
username和password在LoginSelect.jsp验证是否一致使用session.setAttribute( login_msg , 用户名或密码为空 )设置login_msg的值使用session.getAttribute( login_msg )获取对象的值，判断输入框是否为空，如果为空，则提示用户名或密码为空。%@ page contentType="text/html;charset=UTF-8" language="java" % html head title 登录界面 /title /head body div align="center" h1 欢迎登录 /h1 form action="LoginSelect.jsp" method="post" id="form" p 用户名: nbsp input id="username" name="username" type="text" nbsp nbsp /p p 密码: nbsp input id="password" name="password" type="password" /p input type="submit" class="button" value="登录" onclick="" button a href="register.jsp" rel="external nofollow" 注册 /a /button /form div id="errorMsg" value="null" %=session.getAttribute("login_msg")% /div /div script if(document.getElementById("errorMsg").innerText==="null"||document.getElementById("errorMsg").innerText===""){ document.getElementById("errorMsg").setAttribute('style',"display:none") } else { document.getElementById("errorMsg").setAttribute('style',"display:block") } /script /body /html
map.put( 20201234 , 123456 )设置初始数据map.put(username,session.getAttribute(username).toString())这里是将注册的账户和密码添加到数据库中，username为键，session.getAttribute(username).toString()为值，两者都为字符串类型%@ page import="java.util.*" % %@ page contentType="text/html;charset=UTF-8" language="java" % html head title 判断登录界面 /title /head body %! Map String,String map = new HashMap String,String (); public boolean compare(String username,String password){ String pwd = map.get(username); if(pwd!=null password.equals(pwd)){ return true; } else{ return false; } }% % String username = request.getParameter("username"); String password = request.getParameter("password"); //设置初始值 map.put("20201234","123456"); //注册后的值存入map集合 if (session.getAttribute(username)!=null){ map.put(username,session.getAttribute(username).toString()); } System.out.println(map); //判断输入内容是否正确,给出提示信息 if (username==null||username =="" || password==null || password==""){ session.setAttribute("login_msg","用户名或密码为空"); response.sendRedirect("login.jsp"); return; } boolean compare = compare(username, password); if (compare){ session.setAttribute("username",username); session.setAttribute("password",password); response.sendRedirect("index.jsp"); } else { session.setAttribute("login_msg","用户名或密码错误或用户名不存在"); response.sendRedirect("login.jsp"); }% /body /html
username和password在RegisterSelect.jsp验证是否一致使用session.setAttribute( register_msg , 用户名或密码为空 )设置register_msg的值使用session.getAttribute( register_msg )获取对象的值，判断输入框是否为空，如果为空，则提示用户名或密码为空。%@ page contentType="text/html;charset=UTF-8" language="java" % html head title 注册界面 /title /head div align="center" h1 欢迎注册 /h1 form action="RegisterSelect.jsp" method="post" table tr td 用户名 /td td input name="username" type="text" id="username" br /td /tr tr td 密码 /td td input name="password" type="password" id="password" br /td /tr /table input value="注 册" type="submit" id="reg_btn" br span 已有帐号？ /span a href="login.jsp" rel="external nofollow" rel="external nofollow" 登录 /a /form span id="register_msg" class="err_msg" %=session.getAttribute("register_msg")% /span /div /body /div script if(document.getElementById("register_msg").innerText==="null"||document.getElementById("register_msg").innerText===""){ document.getElementById("register_msg").setAttribute('style',"display:none") } else { document.getElementById("register_msg").setAttribute('style',"display:block") } /script /html
if else语句，if 判断账户或密码为空则提示 用户或密码为空 ，else 使用session.setAttribute(username,password) 创建对象存储新的账户和密码信息。%@ page contentType="text/html;charset=UTF-8" language="java" % % String username = request.getParameter("username"); String password = request.getParameter("password"); session.setAttribute("register_msg","null"); if (username==null||username =="" || password==null || password==""){ session.setAttribute("register_msg","用户名或密码为空"); response.sendRedirect("register.jsp"); return; } else { session.setAttribute(username,password); response.sendRedirect("login.jsp"); }% html head title Title /title /head body /body /html
session.getAttribute( username )动态获取账户名称%@ page contentType="text/html;charset=UTF-8" language="java" % html head title 登录成功 /title /head body div align="center" h1 JSP管理系统 /h1 h1 %=session.getAttribute("username")% 欢迎您! /h1 a href="login.jsp" rel="external nofollow" rel="external nofollow" 退出登录 /a /div /body /html
JSP实现简单的登录和注册界面详细全过程
