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@Controller
@RequestMapping("/captcha")
public class CaptchaController {
private char[] codeSequence = {'A', '1', 'B', 'C', '2', 'D', '3', 'E', '4', 'F', '5', 'G', '6', 'H', '7', 'I', '8', 'J',
'K', '9', 'L', '1', 'M', '2', 'N', 'P', '3', 'Q', '4', 'R', 'S', 'T', 'U', 'V', 'W',
'X', 'Y', 'Z'};
@RequestMapping("/code")
public void getCode(HttpServletResponse response, HttpSession session) throws IOException {
int width = 80;
int height = 37;
Random random = new Random();
//设置response头信息
//禁止缓存
response.setHeader("Pragma", "No-cache");
response.setHeader("Cache-Control", "no-cache");
response.setDateHeader("Expires", 0);
//生成缓冲区image类
BufferedImage image = new BufferedImage(width, height, 1);
//产生image类的Graphics用于绘制操作
Graphics g = image.getGraphics();
//Graphics类的样式
g.setColor(this.getColor(200, 250));
g.setFont(new Font("Times New Roman", 0, 28));
g.fillRect(0, 0, width, height);
//绘制干扰线
for (int i = 0; i < 40; i++) {
g.setColor(this.getColor(130, 200));
int x = random.nextInt(width);
int y = random.nextInt(height);
int x1 = random.nextInt(12);
int y1 = random.nextInt(12);
g.drawLine(x, y, x + x1, y + y1);
}
//绘制字符
String strCode = "";
for (int i = 0; i < 4; i++) {
String rand = String.valueOf(codeSequence[random.nextInt(codeSequence.length)]);
strCode = strCode + rand;
g.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110)));
g.drawString(rand, 13 * i + 6, 28);
}
//将字符保存到session中用于前端的验证
session.setAttribute("captcha", strCode.toLowerCase());
g.dispose();
ImageIO.write(image, "JPEG", response.getOutputStream());
response.getOutputStream().flush();
}
public Color getColor(int fc, int bc) {
Random random = new Random();
if (fc > 255)
fc = 255;
if (bc > 255)
bc = 255;
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);
}
}
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