package com.itheima.web.servlet.session;

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.*;


@WebServlet(urlPatterns = "/LoginServlet")
public class LoginServlet extends HttpServlet {
    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException,
            IOException {
        // 处理响应中文乱码    
        response.setContentType("text/html;charset=utf-8");

        String vc = request.getParameter("verifyCode");
        String code_session = (String) request.getSession().getAttribute("code_session");

        if(code_session.equalsIgnoreCase(vc)){

            //response.getWriter().write("
验证码校验成功！");
            String username = request.getParameter("username");
            String password = request.getParameter("password");
            boolean flag=false;

            BufferedReader br = new BufferedReader(new FileReader("d:/stu.txt"));
            String line;
            while((line=br.readLine())!=null){
                System.out.println(line);
                String uname = line.split("\,")[0];
                System.out.println(uname);
                String pword = line.split("\,")[1];
                System.out.println(pword);
                if(username.equals(uname)&&pword.equals(password)){
                    flag=true;
                }
            }

            if(flag){
                request.getSession().setAttribute("username",username);
                response.sendRedirect(request.getContextPath()+"/success.html");
            }
            else{
                response.sendRedirect(request.getContextPath()+"/fail.html");
            }
        }else{
            response.getWriter().write("
验证码校验失败！");
        }

    }

    public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException,
            IOException {
        // 处理请求的中文乱码    
        request.setCharacterEncoding("utf-8");
        doGet(request, response);
    }

}

package com.itheima.web.servlet.session;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@WebServlet("/checkcodeServlet")
public class CheckcodeServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;

	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		//  创建画布
		int width = 120;
		int height = 40;
		BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
		//  获得画笔
		Graphics g = bufferedImage.getGraphics();
		//  填充背景颜色
		g.setColor(Color.white);
		g.fillRect(0, 0, width, height);
		//  绘制边框
		g.setColor(Color.red);
		g.drawRect(0, 0, width - 1, height - 1);
		//  生成随机字符
		//  准备数据
		String data = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890";
		//  准备随机对象
		Random r = new Random();
		//  声明一个变量 保存验证码
		String code = "";
		//  书写4个随机字符
		for (int i = 0; i < 4; i++) {
			//  设置字体
			g.setFont(new Font("宋体", Font.BOLD, 28));
			//  设置随机颜色
			g.setColor(new Color(r.nextInt(255), r.nextInt(255), r.nextInt(255)));

			String str = data.charAt(r.nextInt(data.length())) + "";
			g.drawString(str, 10 + i * 28, 30);

			//  将新的字符 保存到验证码中
			code = code + str;
		}
		//  绘制干扰线
		for (int i = 0; i < 6; i++) {
			//  设置随机颜色
			g.setColor(new Color(r.nextInt(255), r.nextInt(255), r.nextInt(255)));

			g.drawLine(r.nextInt(width), r.nextInt(height), r.nextInt(width), r.nextInt(height));
		}

		//  将验证码 打印到控制台
		System.out.println(code);

		//  将验证码放到session中
		request.getSession().setAttribute("code_session", code);

		//  将画布显示在浏览器中
		ImageIO.write(bufferedImage, "jpg", response.getOutputStream());
	}

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

}

package com.itheima.web.servlet.session;

import javax.servlet.RequestDispatcher;
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;


@WebServlet(urlPatterns = "/ShowPriServlet")
public class ShowPriServlet extends HttpServlet {
    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException,
            IOException {
        // 处理响应中文乱码    
        response.setContentType("text/html;charset=utf-8");

        String username = (String)request.getSession().getAttribute("username");

        if(username!=null){
            request.getRequestDispatcher("/WEB-INF/pri.html").forward(request,response);
        }else{
            response.getWriter().write("
你还未登陆，无法查看已有权限，请先登录  ");

        }


    }

    public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException,
            IOException {
        // 处理请求的中文乱码    
        request.setCharacterEncoding("utf-8");
        doGet(request, response);
    }

}

    
        
        
        
    
    
        

            用户名：

            密 码：

            验证码：  
            
            

            
        
    

    
        
        
    
    
        
恭喜您，登陆成功！
        查看我的权限
    

    
        
        
    
    
        
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