JSP实现后台登录

「爱情、让人受尽委屈。」 2024-02-18 20:17 48阅读 0赞

![20180520210035324][]

![20180520210049282][]

![20180520210123776][]

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
    <%
    String path = request.getContextPath();
    String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
    %>
    
    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
    <html>
      <head>
        <base href="<%=basePath%>">
        
        <title>My JSP 'login_error.jsp' starting page</title>
        
    	<meta http-equiv="pragma" content="no-cache">
    	<meta http-equiv="cache-control" content="no-cache">
    	<meta http-equiv="expires" content="0">    
    	<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    	<meta http-equiv="description" content="This is my page">
    	
    			<style>
    			*{
    				margin:0px;
    				padding: 0px;
    			}
    			#t1{
    				width:500px;  
    			    height:300px;
    			    background: #FFE4C4;  
    			    position:absolute;  
    			    left:50%;  
    		 	    top:50%;  
    	 		    margin:-150px 0 0 -250px;
    	 		    text-align: center;
    	 		    line-height: 300px;
    	 		    font-size:22px;
    			}
    			#myProgress {
      width: 100%;
      height: 30px;
      position: relative;
      background-color: #ddd;
    }
    
    #myBar {
      background-color: #4CAF50;
      width: 10px;
      height: 30px;
      position: absolute;
    }
    		</style>
    
      </head>
      
      <body>
      		<div id="t1">
      			
    		    <p>密码或验证码输入错误,0分3秒后可跳转至login页</p>
    		</div>
    		<div id="myProgress">
      			<div id="myBar"></div>
    		</div>
    		<script type="text/javascript">
    			function move() {
      var elem = document.getElementById("myBar");   
      var width = 0;
      var id = setInterval(frame, 20);
      function frame() {
        if (width == 100) {
          clearInterval(id);  
    		
    
          
        } else {
          width++; 
          elem.style.width = width + '%'; 
        }
      }
    }
    			
    			
    			
    			var maxtime = 2; //按秒计算，自己调整!   
                function CountDown() {
                    if (maxtime >= 0) {
                        minutes = Math.floor(maxtime / 60);
                        seconds = Math.floor(maxtime % 60);
                        msg = "密码或验证码输入错误," + minutes + "分" + seconds + "秒后可跳转至login页";
                        document.getElementById("t1").innerHTML=msg;
                        //document.all["t1"].innerHTML = msg;
                        //if (maxtime == 5 * 60)alert("还剩5分钟");
                            --maxtime;
                    } else{
                        clearInterval(timer);
                        //alert("时间到，结束!");
                        window.location.href='./login.jsp';
                    }
                }
                
                timer = setInterval("CountDown()", 1000); 
    			move();
    			
    		</script>
        	<%-- <div style="font:20px;text-align:center;top:33%;left:33%;position:absolute;border:1px;border-color:red;">密码或验证码输入错误,3秒钟后跳转至login.jsp</div>
        	<script type="text/javascript">
        		window.navigator('./login.jsp');
        		
        	</script>
        	<%
        	out.println( "<HTML><HEAD><META http-equiv='refresh' content='3; URL=/login/login.jsp' target=Main></HEAD><BODY bgcolor='#FFFFFF'></body></html>");
        	//out.println("<script language='javascript'>alert('账号或者密码输入不正确--您的操作有误!');window.location.href='/login/login.jsp';</script>");
        	 %> --%>
        	 
      </body>
    </html>

verify.jsp

<%@ page language="java" import="java.util.*,com.JDBCUtil,java.sql.*" pageEncoding="utf-8"%>
    
    
    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
    <html>
      <head>
        
        
        <title>My JSP 'verify.jsp' starting page</title>
        
    	<meta http-equiv="pragma" content="no-cache">
    	<meta http-equiv="cache-control" content="no-cache">
    	<meta http-equiv="expires" content="0">    
    	<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    	<meta http-equiv="description" content="This is my page">
    
      </head>
      
      <body>
        <%
        	String rand =(String)session.getAttribute("rand");
        	String input =request.getParameter("verify");
        	if(rand.equals(input))
        	{
    	    	String strUser=request.getParameter("user");
    	    	String strPass=request.getParameter("pass");
    	    	//打开连接
    	    	Connection conn = JDBCUtil.getConnection();
    	    	//设置sql语句和sql参数
    	    	String sql="select  COUNT(*)  from Admin where a_name= ? and a_pass= ?";
    	    	Object[] param =new Object[2];
    	    	param[0]=strUser;
    	    	param[1]=strPass;
    	    	//查询并返回结果集
    	    	ResultSet rs=JDBCUtil.doParamQuery(sql, param);
    	    	//将指针移动到第一行
    	    	rs.next();
    	    	//显示第一行第一列的值
    	    	System.out.println("数据库有"+rs.getInt(1)+"条记录与此相符合");
    	    	if(rs.getInt(1)==1){
    	    		System.out.println("登录成功");
    	    		//保存登录状态信息
    	    		session.setAttribute("login", "ok");
    	    		session.setAttribute("me", strUser);
    	    		response.sendRedirect("./login_ok.jsp");
    	    		
    	    		
    	    	}else{
    	    		System.out.println("登录失败");	    		
    	    	
    	    		response.sendRedirect("./login_error.jsp");
    	    		//直接在此页返回login.jsp,会使验证码不刷新,故使用跳转至错误处理页,再跳转至login.jsp
    	    	    //out.println("<script>alert('登录失败')</script>");
    	    		//window.history.back(-1);验证码不刷新
    	    	    //out.println("<script>window.history.back(-1);</script>");
    	    		//out.println("<script>window.location.href('./index.jsp')</script>");
    	    	}
        	}else{
        		out.println("<script>alert('验证码错误')</script>");
        		response.sendRedirect("./login_error.jsp");
        		//直接在此页返回login.jsp,会使验证码不刷新,故使用跳转至错误处理页,再跳转至login.jsp
        		//out.println("<script>alert('验证码错误')</script>");
        		//out.println("<script>window.history.back(-1);</script>");
        		//out.println("<script>window.location.href('./index.jsp')</script>");
        	}
        	
        	
        	/*if(strUser.equals("admin")&&strPass.equals("admin")&&rand.equals(input)){
        		out.println("<h3>登陆成功</h3>");
        	}else{
        		out.println("<h3>登陆失败</h3>");
        	}*/
        	/*if(strUser.equals("admin"))
        	{
        		if(strPass.equals("admin"))
        		{
        			if(rand.equals(input))
        			{
        				out.println("<script>alert('登录成功')</script>");
        				out.println("登录成功");
        			}
        			else{
        				out.println("<script>alert('验证码错误')</script>");
        				out.println("<script>window.location.href('./index.jsp')</script>");    			
        			}    		
        		}
        		else{
        			out.println("<script>alert('密码错误')</script>");
        			out.println("<script>window.location.href('./index.jsp')</script>");    			
        		}    	
        	}
        	else
        	{
        		out.println("<script>alert('用户名不存在')</script>");
        		out.println("<script>window.location.href('./index.jsp')</script>");
        	}
        	*/
         %>
      </body>
    </html>

verifyCode.jsp

<%@ page contentType="image/jpeg"  language="java"  pageEncoding="utf-8"%>
    
    <%@ page import="java.util.*,java.awt.*,java.awt.image.*,javax.imageio.*"%>
    
    <%!
    	Color getRandColor(int fc,int bc)
    	{        
            if(fc>255) fc=255;
            if(bc>255) bc=255;
            //随机生成rgb颜色
            Random random = new Random();
            int r=fc+random.nextInt(bc-fc);
            int g=fc+random.nextInt(bc-fc);
            int b=fc+random.nextInt(bc-fc);
            return new Color(r,g,b);
        }
    %>
    <%
    //设置页面不缓存
    response.setHeader("Pragma","No-cache");
    response.setHeader("Cache-Control","no-cache");
    response.setDateHeader("Expires", 0);
    // 在内存中创建图象
    int width=60, height=20;
    BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
    
    // 获取图形上下文
    Graphics g = image.getGraphics();
    
    //生成随机类
    Random random = new Random();
    
    // 设定背景色
    g.setColor(getRandColor(200,250));
    g.fillRect(0, 0, width, height);
    
    //设定字体
    g.setFont(new Font("Times New Roman",Font.PLAIN,22));
    
    //画边框
    //g.setColor(new Color());
    //g.drawRect(0,0,width-1,height-1);
    
    // 随机产生155条干扰线，使图象中的认证码不易被其它程序探测到
    g.setColor(getRandColor(160,200));
    for (int i=0;i<155;i++)
    {
     	int x = random.nextInt(width);
     	int y = random.nextInt(height);
        int xl = random.nextInt(12);
        int yl = random.nextInt(12);
     	g.drawLine(x,y,x+xl,y+yl);
    }
    
    // 取随机产生的认证码(4位数字)
    String sRand="";
    for (int i=0;i<4;i++){
        String rand=String.valueOf(random.nextInt(10));
        sRand+=rand;
        // 将认证码显示到图象中
        g.setColor(new Color(20+random.nextInt(110),40+random.nextInt(110),60+random.nextInt(110)));
    	//调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成
        g.drawString(rand,13*i+6,16);
    }
    
    // 将认证码存入SESSION
    session.setAttribute("rand",sRand);
    
    // 图象生效
    g.dispose();
    
    // 输出图象到页面
    ImageIO.write(image, "JPEG", response.getOutputStream());
    %>

[20180520210035324]: https://image.dandelioncloud.cn/pgy_files/images/2024/01/29/0f95d050b7eb4e90a1364875c5a84be1.png
[20180520210049282]: https://image.dandelioncloud.cn/pgy_files/images/2024/01/29/4a7e977383a841b497450d476b34edab.png
[20180520210123776]: https://image.dandelioncloud.cn/pgy_files/images/2024/01/29/046b6d014d6544fdbe0f81378559b3e1.png