check.java

SERVLET 基于SERVLET+MYSQL实现的用户登陆

import java.io.*;
import java.net.*;
import java.sql.*;
import javax.sql.*;
import inc.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class check extends HttpServlet {
  public void doGet(HttpServletRequest request, HttpServletResponse response) throws
      ServletException, IOException {
    response.setContentType("text/html;charset=UTF-8");
    PrintWriter out = response.getWriter();
	HttpSession session = request.getSession();
    //取得用户名和密码
    String oopname = request.getParameter("oopname");
    String ooppassword = request.getParameter("ooppassword");
    String rand = (String)session.getAttribute("rand");
	String input = request.getParameter("rand");
	 if (!rand.equals(input)) {
	 out.println("<script>alert(\"验证码错误！\");window.document.location.href=\"login.oop\";</script>");
	 }
	 else {
          try {
            String sql = "select * from oopuser where oopname='" + oopname + "' and ooppassword='" + ooppassword + "'";
            ResultSet rs = null;
            condb conn = new condb();
            rs = conn.executeQuery(sql);
             //如果不存在，就返回首页
                  if (!rs.next()) {
                    out.println("<script>\r\n");
                    out.println("{ \r\n");
                    out.println("alert(\"对不起，你输入的用户名和密码有误，或者不存在，请与管理员联系\"); \r\n");
                    out.println("window.document.location.href=\"login.oop\";\r\n");
                    out.println("}\r\n");
                    out.println("</script>");
                    return;
                   }
                  else {
                        session.setAttribute("oopname", oopname);
						out.println("登陆成功");
                        response.sendRedirect("main.oop");

                   }
                 }
                 catch (Exception e) { out.println("异常");
                 }
			}
  }

  public void doPost(HttpServletRequest request, HttpServletResponse response) throws
      ServletException, IOException {
    doGet(request, response);
  }
}