After the graphic verification code is prepared, it is sent to the login page through Session.
package cn.edu.mju.project24.controller;
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 java.io.IOException;
import java.io.PrintWriter;
@WebServlet("/login")
public class LoginController extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
StringBuilder stringBuilder=new StringBuilder();
stringBuilder.append("<form action='' method='post'>");
stringBuilder.append("登录名称: <input type='text' name='loginName' value=''><br>");
stringBuilder.append("登录密码: <input type='Password' name='loginPwd' value=''><br>");
stringBuilder.append("验证码: <input type='text' name='validCode' value=''><br><img src='./captche' width='100' height='80'><br>");
stringBuilder.append("<input type='reset' name='reset' value='取消'>");
stringBuilder.append(" <input type='submit' name='submit' value='登录'>");
stringBuilder.append("</form>");
showMsg(resp,stringBuilder.toString());
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
req.setCharacterEncoding("UTF-8");
String loginName = req.getParameter("loginName");
String loginPwd = req.getParameter("loginPwd");
String validCode = req.getParameter("validCode");
String code=(String) req.getSession().getAttribute("code");
String msg;
if("3187102439".equals(loginName)&& "1234".equals(loginPwd)&& validCode.equals(code))
{
msg="登录成功";
}
else{
msg="登录失败！" ;
}
showMsg(resp,msg);
}
private void showMsg(HttpServletResponse resp,String msg) throws IOException{
resp.setCharacterEncoding("UTF-8");
StringBuilder stringBuilder=new StringBuilder();
stringBuilder.append("<html>");
stringBuilder.append("<header>");
stringBuilder.append("<title>Text</title>");
stringBuilder.append("<meta http-equiv=\"Content-Type\" content=\"text/html;charset=utf-8\">");
stringBuilder.append("</header>");
stringBuilder.append("<body>");
stringBuilder.append(msg);
stringBuilder.append("</form>");
stringBuilder.append("</body>");
stringBuilder.append("</html>");
PrintWriter out =resp.getWriter();
out.println(stringBuilder.toString());
out.close();
}
}
Enter the correct name, password and verification code.
Click to Login.
login successful
