1 import java.awt.Color;
2 import java.awt.Font;
3 import java.awt.Graphics2D;
4 import java.awt.image.BufferedImage;
5 import java.io.IOException;
6 import java.util.ArrayList;
7 import java.util.List;
8 import java.util.Random;
9
10 import javax.imageio.ImageIO;
11 import javax.servlet.ServletException;
12 import javax.servlet.ServletOutputStream;
13 import javax.servlet.annotation.WebServlet;
14 import javax.servlet.http.HttpServlet;
15 import javax.servlet.http.HttpServletRequest;
16 import javax.servlet.http.HttpServletResponse;
17 import javax.servlet.http.HttpSession;
18
19 @WebServlet("/validcode")
20 public class ValidCodeServlet extends HttpServlet {
21 @Override
22 protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
23 //创建一张图片
24 //单位:像素
25 BufferedImage image = new BufferedImage(200, 100, BufferedImage.TYPE_INT_RGB);
26
27 //透明的玻璃
28 //向画板上画内容之前必须先设置画笔.
29 Graphics2D gra = image.createGraphics();
30
31 gra.setColor(Color.WHITE);
32 //从哪个坐标开始填充, 后两个参数,矩形区域
33 gra.fillRect(0, 0, 200, 100);
34
35 List<Integer> randList = new ArrayList<Integer>();
36 Random random =new Random();
37 for (int i = 0 ;i<4;i++) {
38 randList.add(random.nextInt(10));
39 }
40 //设置字体
41 gra.setFont(new Font("宋体",Font.ITALIC|Font.BOLD,40));
42 Color[] colors = new Color[]{Color.RED,Color.YELLOW,Color.BLUE,Color.GREEN,Color.PINK,Color.GRAY};
43 for (int i = 0; i < randList.size(); i++) {
44 gra.setColor(colors[random.nextInt(colors.length)]);
45 gra.drawString(randList.get(i)+"", i*40, 70+(random.nextInt(21)-10));
46 }
47
48 for (int i = 0; i < 2; i++) {
49 gra.setColor(colors[random.nextInt(colors.length)]);
50 //画横线
51 gra.drawLine(0, random.nextInt(101), 200, random.nextInt(101));
52 }
53
54 ServletOutputStream outputStream = resp.getOutputStream();
55 //工具类
56 ImageIO.write(image, "jpg", outputStream);
57
58 //把验证码放入到session中
59 HttpSession session = req.getSession();
60 session.setAttribute("code", ""+randList.get(0)+randList.get(1)+randList.get(2)+randList.get(3));
61 }
62 }
