防機器登入驗證碼的實現 與 輸入匹配驗證
阿新 • • 發佈:2019-01-27
程式碼:
login.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>登入驗證</title> <script type="text/javascript"> function changeImage() { var img = document.getElementsByTagName("img")[0]; img.src="${pageContext.request.contextPath }/ImageServlet?time="+new Date().getTime();//這個目的是防止快取不重新整理驗證碼 } function check(){ var uname = document.getElementById("uname").value; var upassword = document.getElementById("upassword").value; var verifycode = document.getElementById("verifycode").value; var validateCode = '<%=session.getAttribute("validateCode")%>' if(uname==""){ alert("使用者名稱為空!"); return false; } if(upassword==""){ alert("密碼為空!"); return false; } if(verifycode==""){ alert("請填寫驗證碼!"); return false; } if(validateCode.equals(verifycode)){ alert("驗證碼錯誤!"); return false; } } if(window.top!=window){ window.top.location = "Login"; } </script> </head> <body> <center> <h1>使用者登入</h1> <hr/> <% Object validateCode = session.getAttribute("validateCode"); System.out.println("你的驗證碼是:"+validateCode); %> <form action="Login" method="post" onsubmit="return check()"> <table border="0" width="360px"> <tr> <td align="right">使用者名稱:</td> <td><input type="text" id="uname" name="username" style="width: 180px"/></td> </tr> <tr> <td align="right">密 碼:</td> <td><input type="password" id="upassword" name="password" style="width: 180px"/></td> </tr> <tr> <td align="right">驗證碼:</td> <td><input type="text" id="verifycode" style="width: 180px" name="verifycode"/></td> <td><img alt="換一張看看" src="/Siemens/ImageServlet" align="left" onclick="changeImage()" /></td> </tr> <tr> <td><input type="radio" name="kind" value="員工" checked="checked">員工</td> <td><input type="radio" name="kind" value="管理員">管理員</td> </tr> <tr> <td align="right"><input type="submit" value="登入"/></td> <td><input type="reset" value="重置"/></td> </tr> <tr> <td></td> <td><font color="red">${message}</font></td> </tr> <tr> <td></td> <td><font color="red">${verify}</font></td> </tr> </table> </form> </center> </body> </html>
ImageServlet.java(生成驗證碼圖片的servlet)
package com.servlet; import java.awt.Color; import java.awt.Font; import java.awt.Graphics2D; import java.awt.image.BufferedImage; import java.util.Random; import javax.imageio.ImageIO; import javax.servlet.ServletException; import javax.servlet.ServletOutputStream; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; @WebServlet("/ImageServlet") public class ImageServlet extends HttpServlet { private static final long serialVersionUID = 1L; // 驗證碼圖片的寬度。 private int width = 100; // 驗證碼圖片的高度。 private int height = 25; // 驗證碼字元個數 private int codeCount = 4; private int x = 0; // 字型高度 private int fontHeight; private int codeY; char[] codeSequence = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' }; /** * 初始化驗證圖片屬性 */ public void init() throws ServletException { // 從web.xml中獲取初始資訊 // 寬度 String strWidth = this.getInitParameter("width"); // 高度 String strHeight = this.getInitParameter("height"); // 字元個數 String strCodeCount = this.getInitParameter("codeCount"); // 將配置的資訊轉換成數值 try { if (strWidth != null && strWidth.length() != 0) { width = Integer.parseInt(strWidth); } if (strHeight != null && strHeight.length() != 0) { height = Integer.parseInt(strHeight); } if (strCodeCount != null && strCodeCount.length() != 0) { codeCount = Integer.parseInt(strCodeCount); } } catch (NumberFormatException e) { e.printStackTrace(); } x = width / (codeCount + 1); fontHeight = height - 2; codeY = height - 4; } protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, java.io.IOException { // 定義影象buffer BufferedImage buffImg = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); Graphics2D g = buffImg.createGraphics(); // 建立一個隨機數生成器類 Random random = new Random(); // 將影象填充為白色 g.setColor(Color.WHITE); g.fillRect(0, 0, width, height); // 建立字型,字型的大小應該根據圖片的高度來定。 Font font = new Font("Fixedsys", Font.PLAIN, fontHeight); // 設定字型。 g.setFont(font); // 畫邊框。 g.setColor(Color.BLACK); g.drawRect(0, 0, width - 1, height - 1); // 隨機產生160條幹擾線,使圖象中的認證碼不易被其它程式探測到。 g.setColor(Color.BLACK); for (int i = 0; i < 160; i++) { int x = random.nextInt(width); int y = random.nextInt(height); int xl = random.nextInt(12); int yl = random.nextInt(12); g.drawLine(x, y, x + xl, y + yl); } // randomCode用於儲存隨機產生的驗證碼,以便使用者登入後進行驗證。 StringBuffer randomCode = new StringBuffer(); int red = 0, green = 0, blue = 0; // 隨機產生codeCount數字的驗證碼。 for (int i = 0; i < codeCount; i++) { // 得到隨機產生的驗證碼數字。 String strRand = String.valueOf(codeSequence[random.nextInt(36)]); // 產生隨機的顏色分量來構造顏色值,這樣輸出的每位數字的顏色值都將不同。 red = random.nextInt(255); green = random.nextInt(255); blue = random.nextInt(255); // 用隨機產生的顏色將驗證碼繪製到影象中。 g.setColor(new Color(red, green, blue)); g.drawString(strRand, (i + 1) * x, codeY); // 將產生的四個隨機數組合在一起。 randomCode.append(strRand); } // 將四位數字的驗證碼儲存到Session中。 HttpSession session = req.getSession(); session.setAttribute("validateCode", randomCode.toString()); // 禁止影象快取。 resp.setHeader("Pragma", "no-cache"); resp.setHeader("Cache-Control", "no-cache"); resp.setDateHeader("Expires", 0); resp.setContentType("image/jpeg"); // 將影象輸出到Servlet輸出流中。 ServletOutputStream sos = resp.getOutputStream(); ImageIO.write(buffImg, "jpeg", sos); sos.close(); } }
登入驗證
Login.java
截圖:package com.servlet; import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import com.bean.User; import com.dao.UserDao; @WebServlet("/Login") public class Login extends HttpServlet { private static final long serialVersionUID = 1L; public Login() { super(); // TODO Auto-generated constructor stub } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub doPost(request, response); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub //設定編碼 request.setCharacterEncoding("utf-8"); response.setCharacterEncoding("utf-8"); response.setHeader("Content-Type","text/html; charset=utf-8"); HttpSession session = request.getSession(); String validation_code = (String)session.getAttribute("validateCode"); String user_name = request.getParameter("username"); String user_password = request.getParameter("password"); String user_kind = request.getParameter("kind"); String verifycode = request.getParameter("verifycode"); UserDao dao = new UserDao(); User user = dao.login(user_name, user_password, user_kind); System.out.println("使用者"+user+user_name+user_password+user_kind); //request.getSession().setAttribute("username", user_name); if(!verifycode.equalsIgnoreCase(validation_code)){ request.getSession().setAttribute("verify", "驗證碼錯誤,請重新輸入!"); //輸入的驗證碼與圖片的驗證碼不一致 response.sendRedirect(request.getContextPath()+"/login.jsp"); } else{ if(user != null){ request.getSession().setAttribute("user", user); if(user_kind.equals("管理員")){ request.getRequestDispatcher("jsp/ManagerMainPage.jsp").forward(request, response); //response.sendRedirect("jsp/ManagerMainPage.jsp"); return; } else{ request.getRequestDispatcher("jsp/EmployeeMainPage.jsp").forward(request, response); //response.sendRedirect("jsp/EmployeeMainPage.jsp"); return; } } else{ request.getSession().setAttribute("message", "使用者名稱或密碼錯誤!"); //登入資訊驗證錯誤 //response.getWriter().write("<script language='javascript'>alert('使用者名稱或密碼不正確!')</script>"); //request.getRequestDispatcher("/login.jsp").forward(request, response); response.sendRedirect(request.getContextPath()+"/login.jsp"); } } } }
#密碼正確,驗證碼匹配,登入成功