HTML
1 <!DOCTYPE html> 2 <html lang="zh-CN"> 3 <head> 4 <meta charset="UTF-8" /> 5 <meta name="viewport" content="width=device-width, initial-scale=1.0" /> 6 <title>用戶登錄</title> 7 <link rel="stylesheet" href="CSS/login.css" /> 8 </head> 9 <body> 10 <form name="user" action="LoginServlet" method="post"> 11 <div class="login"> 12 <h2>用戶登錄</h2> 13 <div class="login_box"> 14 <input type="text" name="uid" id="uid" autocomplete="off"/><label>用戶名</label> 15 </div> 16 <div class="login_box"> 17 <input type="password" name="password" id="password" autocomplete="off"/><label>密碼</label> 18 </div> 19 <a href="#" onclick="document.user.submit();return false"> 20 登錄 21 <span></span> 22 <span></span> 23 <span></span> 24 <span></span> 25 </a> 26 </div> 27 </form> 28 </body> 29 </html>
CSS
* { /* 初始化 清除頁面元素的內外邊距 */ padding: 0; margin: 0; /* 盒子模型 */ box-sizing: border-box; } body { /* 彈性布局 讓頁面元素垂直+水平居中 */ display: flex; justify-content: center; align-items: center; /* 讓頁面始終占瀏覽器可視區域總高度 */ height: 100vh; /* 背景漸變色 */ background: linear-gradient(#141e30, #243b55); } .login { /* 彈性布局 讓子元素稱為彈性項目 */ display: flex; /* 讓彈性項目垂直排列 原理是改變彈性盒子的主軸方向 父元素就是彈性盒子 現在改變后的主軸方向是向下了 */ flex-direction: column; /* 讓彈性項目在交叉軸方向水平居中 現在主軸的方向是向下 交叉軸的方向是與主軸垂直 交叉軸的方向是向右 */ align-items: center; width: 400px; padding: 40px; background-color: rgba(0, 0, 0, 0.2); box-shadow: 0 15px 25px rgba(0, 0, 0, 0.4); } .login h2 { color: #fff; margin-bottom: 30px; } .login .login_box { /* 相對定位 */ position: relative; width: 100%; } .login .login_box input { /* 清除input框自帶的邊框和輪廓 */ outline: none; border: none; width: 100%; padding: 10px 0; margin-bottom: 30px; color: #fff; font-size: 16px; border-bottom: 1px solid #fff; /* 背景顏色為透明色 */ background-color: transparent; } .login .login_box label { position: absolute; top: 0; left: 0; padding: 10px 0; color: #fff; /* 這個屬性的默認值是auto 默認是這個元素可以被點擊 但是如果我們寫了none 就是這個元素不能被點擊 , 就好像它可見但是不能用 可望而不可即 */ /* 這個就是兩者的區別 */ pointer-events: none; /* 加個過渡 */ transition: all 0.5s; } /* :focus 選擇器是當input獲得焦點是觸發的樣式 + 是相鄰兄弟選擇器 去找與input相鄰的兄弟label */ /* :valid 選擇器是判斷input框的內容是否合法,如果合法會執行下面的屬性代碼,不合法就不會執行,我們剛開始寫布局的時候給input框寫了required 我們刪掉看對比 當沒有required的話input框的值就會被認為一直合法,所以一直都是下方的樣式 ,但是密碼不會,密碼框內的值為空,那么這句話局不合法,required不能為空 當我們給密碼框寫點東西的時候才會執行以下代碼*/ .login .login_box input:focus + label, .login .login_box input:valid + label { top: -20px; color: #03e9f4; font-size: 12px; } .login a { overflow: hidden; position: relative; padding: 10px 20px; color: #03e9f4; /* 取消a表現原有的下划線 */ text-decoration: none; /* 同樣加個過渡 */ transition: all 0.5s; } .login a:hover { color: #fff; border-radius: 5px; background-color: #03e9f4; box-shadow: 0 0 5px #03e9f4, 0 0 25px #03e9f4, 0 0 50px #03e9f4, 0 0 100px #03e9f4; } .login a span { position: absolute; } .login a span:first-child { top: 0; left: -100%; width: 100%; height: 2px; /* to right 就是往右邊 下面的同理 */ background: linear-gradient(to right, transparent, #03e9f4); /* 動畫 名稱 時長 linear是勻速運動 infinite是無限次運動 */ animation: move1 1s linear infinite; } .login a span:nth-child(2) { right: 0; top: -100%; width: 2px; height: 100%; background: linear-gradient(transparent, #03e9f4); /* 這里多了個0.25s其實是延遲時間 */ animation: move2 1s linear 0.25s infinite; } .login a span:nth-child(3) { right: -100%; bottom: 0; width: 100%; height: 2px; background: linear-gradient(to left, transparent, #03e9f4); animation: move3 1s linear 0.5s infinite; } .login a span:last-child { left: 0; bottom: -100%; width: 2px; height: 100%; background: linear-gradient(#03e9f4, transparent); animation: move4 1s linear 0.75s infinite; } @keyframes move1 { 0% { left: -100%; } 50%, 100% { left: 100%; } } @keyframes move2 { 0% { top: -100%; } 50%, 100% { top: 100%; } } @keyframes move3 { 0% { right: -100%; } 50%, 100% { right: 100%; } } @keyframes move4 { 0% { bottom: -100%; } 50%, 100% { bottom: 100%; } }
LoginServlet

package servlet; import java.io.IOException; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.text.SimpleDateFormat; import java.util.Date; import javax.servlet.ServletException; import javax.servlet.ServletRequest; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; /** * Servlet implementation class UserServlet */ @WebServlet("/LoginServlet") public class LoginServlet extends HttpServlet { private static final long serialVersionUID = 1L; /** * @see HttpServlet#HttpServlet() */ public LoginServlet() { super(); // TODO Auto-generated constructor stub } /** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub } /** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub response.setContentType("text/html;charset=UTF-8"); request.setCharacterEncoding("UTF-8"); response.setCharacterEncoding("UTF-8"); SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); String date=sdf.format(new Date()); String uid=String.valueOf(request.getParameter("uid")); String pass=String.valueOf(request.getParameter("password")); try { Class.forName("com.mysql.cj.jdbc.Driver"); String url="jdbc:mysql://localhost:3306/family income and expenditure?&useSSL=false&serverTimezone=UTC"; String username="root"; String password=""; Connection conn=DriverManager.getConnection(url,username,password); String sql="select * from user_info where uid='"+uid+"'and password='"+pass+"'"; PreparedStatement ps=conn.prepareStatement(sql); ResultSet rs=ps.executeQuery(); if(rs.next()) { System.out.println(date+" "+uid+" "+"login"); System.out.println(); request.setAttribute("uid", uid); request.getRequestDispatcher("index.html").forward(request,response);//登錄成功 }else{ response.getWriter().write("<font style='color:red;font-size:35px'><div align='center'>"+ "用戶名或密碼錯誤!5秒后自動跳轉"+"</div>"+"</font>"); response.getWriter().write("<div align='center'>" +"如果沒有發生跳轉,請點"+"<a href='login.html'>"+"這里"+"</div>"); response.setHeader("refresh", "5;url=login.html");//登錄失敗,重新登錄 } }catch(Exception e) { e.printStackTrace(); }finally{ } } }