servlet 校验密码
一、实现效果图
登陆成功:
用户不存在:
密码错误:
二、数据库连接代码:
首先要先将jdbc的jar包导入项目中,具体怎么做,网上也有,就不写出来了。
package com.serverlet; import java.io.IOException; import java.io.PrintWriter; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.Statement; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; /** * Servlet implementation class login_servlet */ @WebServlet("/login_servlet") public class login_servlet extends HttpServlet { private static final long serialVersionUID = 1L; /** * @see HttpServlet#HttpServlet() */ public login_servlet() { super(); // TODO Auto-generated constructor stub } /** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub Connection conn=null; Statement stmt = null; response.setContentType("text/html;charset=utf-8"); try { Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");//驱动 PrintWriter out =response.getWriter(); conn=DriverManager.getConnection("jdbc:sqlserver://localhost:1433;databasename=Company","www","www");//连接数据库 stmt =conn.createStatement(); String un=request.getParameter("uname"); String upwd = request.getParameter("upass"); //out.println(upwd+"/n"); String sql = "Select sex from t_ly where name ='"+un+"'"; ResultSet rs = stmt.executeQuery(sql);//执行sql语句 boolean isTrue = false; // boolean isLoginIn = false; while(rs.next()){//遍历整个数据库 String pswd = rs.getString("sex");//取出数据库数据 //out.println(pswd.replace(" ", "")); if(pswd.replace(" ", "").equals(upwd)) { isTrue=true; out.println("欢迎您:"+un); break; } else { isTrue= true; out.println("密码错误,登陆失败"); } } if(isTrue==false) { out.println("用户名不存在"); } rs.close(); stmt.close(); conn.close(); } catch (Exception e) { // TODO: handle exception e.printStackTrace(); } finally { try { if(stmt!=null) { stmt.close(); } } catch (Exception e) { // TODO: handle exception } try { if(conn!=null) { conn.close(); } } catch (Exception e) { // TODO: handle exception } } } /** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub doGet(request, response); } public void destroy() { } }
三、连接
链接:https://pan.baidu.com/s/16cDICRmW-LCpeiaeYF64vg
提取码:oytd
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