星期三

package com.itheima.web;

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("/loginServlet")
public class LoginServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setCharacterEncoding("utf-8");
        // 1.获取参数
        String user=request.getParameter("username");
        String password=request.getParameter("password");
        String inputCode=request.getParameter("inputCode");
        // 2.获取生成的验证码
        String login_code=(String) request.getSession().getAttribute("check_code");
        request.getSession().removeAttribute("check_code");
        // 3.比较验证码
        if(login_code.equalsIgnoreCase(inputCode)==true){
            //验证码正确
            //比较用户名是否正确
            if(user.equals("123456")&&password.equals("123456")){
                //用户信息正确
                //存储信息，用户信息
                request.getSession().setAttribute("name",user);
                //用于测试的输出语句
                System.out.println("1111111111111111");
                //response.sendRedirect(request.getContextPath()+"/success.jsp");
                request.getRequestDispatcher("success.jsp").forward(request,response);
            }
            else {
                //用户信息错误
                //用于测试的输出语句
                //System.out.println("22222222222");
                request.setAttribute("login_error","用户名或密码错误");
                request.getRequestDispatcher("login.jsp").forward(request,response);
            }
        }
        else {
            //验证码错误
            //用于测试的输出语句
            System.out.println("33333333333");
            request.setAttribute("cc_error","验证码错误");
            request.getRequestDispatcher("login.jsp").forward(request,response);
        }
    }

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

　　这是登录的servlet类

package com.itheima.web;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
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 {
    //产生随机的字体
    private Font getFont(){
        //创建random对象，用于生成随机数
        Random random = new Random();
        //创建字体数组，用于封装不同字体的Font对象
        Font font[] = new Font[5];
        font[0] = new Font("Ravie", Font.PLAIN, 24);
        font[1] = new Font("Antique Olive Compact", Font.PLAIN, 24);
        font[2] = new Font("Forte", Font.PLAIN, 24);
        font[3] = new Font("Wide Latin", Font.PLAIN, 24);
        font[4] = new Font("Gill Sans Ultra Bold", Font.PLAIN, 24);
        return font[random.nextInt(5)];
    }
    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        response.setContentType("image/jpeg");
        OutputStream os = response.getOutputStream();
        int width = 166, height = 30;
        //建立指定宽、高和BufferedImage对象
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_BGR);
        Graphics g = image.getGraphics();//将画笔绘制于image上
        Color c= g.getColor();//保存当前画笔的颜色
        g.fillRect(0, 0, width, height);//填充矩形
        char[] ch = "abcdefghigklmnopqrstuvwxyz2345678901".toCharArray();//随机产生字符串
        int length = ch.length;//随机字符串长度
        String sRand = "";//保存随机产生的字符串
        Random random = new Random();
        for (int i=0; i<8; i++){
            g.setFont(getFont());//设置字体
            String rand = new Character(ch[random.nextInt(length)]).toString();//随机生成0~9的数字
            sRand += rand;
            //设置随机颜色
            g.setColor(new Color(random.nextInt(255), random.nextInt(255), random.nextInt(255)));
            g.drawString(rand, 20*i+6, 25);
        }
        request.getSession().setAttribute("check_code",sRand);
        //保存生成的验证码到session中
        //产生随机干扰点
        for(int i=0; i<20; i++){
            int x1 = random.nextInt(width);
            int y1 = random.nextInt(height);
            g.drawOval(x1, y1, 2, 2);
        }
        g.setColor(c);//重置画笔颜色
        g.dispose();//释放此图形的上下文及使用的所有系统资源
        request.getSession().setAttribute("check_code", sRand);//验证码记录到session
        ImageIO.write(image, "JPEG", os);//输出图像到页面
    }

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

        this.doGet(request, response);
    }
}

　　这是生成验证码图片的servlet类