package com.oracle.web; import java.io.IOException; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import javax.servlet.ServletContext; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import com.orecla.tools.JDBCUtils; public class loginServlet extends HttpServlet { public void init() throws ServletException { //定义计数器 int countt = 0; //获取ServletContext对象 ServletContext context = getServletContext(); context.setAttribute("countt", countt); } public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //1、获取前台传来的值，用户名和密码 String username = request.getParameter("username"); String password = request.getParameter("password"); //UserDao层开始 //2、连接数据库连接 Connection conn = JDBCUtils.get(); String sql = "select count(*) from user where uname = ? and pwd = ?"; int count = 0; PreparedStatement pst = null; ResultSet rs = null; try { pst = conn.prepareStatement(sql); pst.setString(1, username); pst.setString(2, password); rs = pst.executeQuery(); while(rs.next()){ count = rs.getInt(1); } } catch (SQLException e) { e.printStackTrace(); }finally{ JDBCUtils.close(conn, pst, rs); } //UserDao层结束 //判断count 值给予给前台提示 if(count >0){ ServletContext context = getServletContext(); int countt = (int)context.getAttribute("countt"); countt++; response.getWriter().write("success");//前台打印 response.getWriter().write("nishidi"+countt+"gerenfangwen"); context.setAttribute("countt", countt); }else{ response.getWriter().write("false");//前台打印 } } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }
<%@ 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>Insert title here</title> </head> <body> <form action="/WEB02/loginServlet" method="post"> 用户名:<input type = "text" name="username"><br> 密码:<input type="password" name="password"><br> <input type="submit" value="提交"> </form> </body> </html>
