java生成验证码

private int					w				= 70;

private int					h				= 26;

/**
* 生成验证码
*/
@RequestMapping
public void captcha(String width, String height, HttpServletResponse response, Model model)
{
OutputStream out = null;
try
{
response.setHeader("Pragma", "no-cache");
response.setHeader("Cache-Control", "no-cache");
response.setDateHeader("Expires", 0);
response.setContentType("image/jpeg");
if (StringUtils.isNumeric(width) && StringUtils.isNumeric(height))
{
w = NumberUtils.toInt(width);
h = NumberUtils.toInt(height);
}
BufferedImage image = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
Graphics g = image.getGraphics();
g.setColor(getRandColor(220, 250));// 生成背景
g.fillRect(0, 0, w, h);
for (int i = 0; i < 8; i++) // 加入干扰线条
{
g.setColor(getRandColor(40, 150));
Random random = new Random();
int x = random.nextInt(w);
int y = random.nextInt(h);
int x1 = random.nextInt(w);
int y1 = random.nextInt(h);
g.drawLine(x, y, x1, y1);
}
String s = createCharacter(g);// 生成字符
SessionUtils.put(Constants.SESSION_KEY_CAPTCHA, s);
g.dispose();
out = response.getOutputStream();
ImageIO.write(image, "JPEG", out);
out.close();
}
catch (Exception e)
{
logger.error("Write Captcha Error", e);
}
finally
{
IOUtils.closeQuietly(out);
}
}

private Color getRandColor(int fc, int bc)
{
int f = fc;
int b = bc;
Random random = new Random();
if (f > 255)
{
f = 255;
}
if (b > 255)
{
b = 255;
}
return new Color(f + random.nextInt(b - f), f + random.nextInt(b - f), f + random.nextInt(b - f));
}

private String createCharacter(Graphics g)
{
char[] codeSeq =
{ 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J', 'K', 'L', 'M', 'N', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', '2', '3', '4', '5', '6', '7', '8', '9' };
//字体：宋体, 新宋体, 黑体, 楷体, 隶书
String[] fontTypes =
{ "\u5b8b\u4f53", "\u65b0\u5b8b\u4f53", "\u9ed1\u4f53", "\u6977\u4f53", "\u96b6\u4e66" };
Random random = new Random();
StringBuilder s = new StringBuilder();
for (int i = 0; i < 4; i++)
{
String r = String.valueOf(codeSeq[random.nextInt(codeSeq.length)]);
g.setColor(new Color(50 + random.nextInt(100), 50 + random.nextInt(100), 50 + random.nextInt(100)));
g.setFont(new Font(fontTypes[random.nextInt(fontTypes.length)], Font.BOLD, 26));
g.drawString(r, 15 * i + 5, 19 + random.nextInt(8));
s.append(r);
}
return s.toString();
}