登錄驗證碼 Servlet / 從請求中獲取數據,獲取驗證碼的session的值轉為String類型, 銷毀,防止返回後驗證碼不刷新,重新驗證成功 判斷驗證碼是否相同(忽略大小寫) 相同:創建user對象調用service層的方法驗證返回結果是否為空 為空:創建session:儲存錯誤信息,轉發,登 ...
登錄驗證碼
Servlet
/*
- 從請求中獲取數據,獲取驗證碼的session的值轉為String類型,
- 銷毀,防止返回後驗證碼不刷新,重新驗證成功
- 判斷驗證碼是否相同(忽略大小寫)
- 相同:創建user對象調用service層的方法驗證返回結果是否為空
為空:創建session:儲存錯誤信息,轉發,登錄頁面顯示登錄名或密碼錯誤
不為空:創建session:儲存用戶名,轉發,到登錄成功頁面 - 不相同:創建session:儲存錯誤信息,登錄頁面顯示驗證碼錯誤(判斷如果session為null不顯示)
public class Servlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
Login login = new service.impl.Login();
String username =request.getParameter("username");
String password = request.getParameter("password");
String code = request.getParameter("code");
Object checkcode1 = request.getSession().getAttribute("checkcode");
String checkcode = (String) checkcode1;
request.getSession().removeAttribute("checkcode");
if (checkcode!=null&&code.equalsIgnoreCase(checkcode)){
User u=new User();
u.setUsername(username);
u.setPassword(password);
User user = login.Login(u);
if (user!=null){ request.getSession().setAttribute("username",username)
request.getRequestDispatcher("Success.jsp").forward(request,response);
}else{ request.getSession().setAttribute("userfail","用戶名或密碼錯誤");
request.getRequestDispatcher("index.jsp").forward(request,response);
} }else{ request.getSession().setAttribute("codefail","驗證碼錯誤");
request.getRequestDispatcher("index.jsp").forward(request,response);
}
}CheckcodeServlet
public class CheckcodeServlet extends HttpServlet { protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//定義驗證碼框的長寬
int width = 100;
int height = 50;
//創建image對象
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
//創建畫筆對象
Graphics graphics = image.getGraphics();
//設置畫筆顏色
graphics.setColor(Color.white);
//填充背景
graphics.fillRect(0, 0, width, height);
//重新設定畫筆顏色 graphics.setColor(Color.BLUE);
//畫驗證碼的邊框
graphics.drawRect(0, 0, width - 1, height - 1);
//將驗證碼所要顯示的內容組成字元串
String s = "QWERTYUIOPASDFGHJKLZXCVBNMqwertyuiopasdfghjklzxcvbnm1234567890";
//創建隨機數對象
Random random = new Random();
//創建顏色數組
Color[] colors = {Color.red, Color.BLACK, Color.magenta, Color.YELLOW, Color.GREEN};
//創建builder對象用於組合驗證碼
StringBuilder builder = new StringBuilder();
//for迴圈畫驗證碼
for (int i = 1; i <= 4; i++) {
//每個字母換一個顏色 graphics.setColor(colors[new Random().nextInt(colors.length)]);
//隨機生成字元串下標
int index = random.nextInt(s.length());
//通過字元串下標拿到字元
char c = s.charAt(index);
//組合字元串
builder.append(c);
//設置驗證碼的字體
graphics.setFont(new Font("Comic Sans MS", Font.BOLD, 20));
//驗證碼所要擺放的位置
graphics.drawString(c + "", width / 5 * i, height / 2);
}
//將驗證碼轉為String類型
String s1 = builder.toString();
//存放在session中 request.getSession().setAttribute("checkcode", s1); //for迴圈畫干擾線
for (int i = 0; i < 30; i++) {
//設置干擾線顏色
graphics.setColor(colors[new Random().nextInt(colors.length)]);
//設置干擾線坐標
int x = random.nextInt(width);
int y = random.nextInt(height);
int x1 = random.nextInt(30);
int y1 = random.nextInt(30);
int sin = random.nextBoolean() ? 1 : -1;
int cos = random.nextBoolean() ? 1 : -1; graphics.drawLine(x, y, x + x1 * sin, y + y1 * cos); }
//輸出驗證碼框
ImageIO.write(image, "jpg", response.getOutputStream());
}
