SpringMVC生成的验证码图片不显示问题及解决方法生成的验证码图片不显示问题及解决方法
主要介绍了SpringMVC生成的验证码图片不显示问题，本文通过实例代码给大家介绍的非常详细，对大家的学
习或工作具有一定的参考借鉴价值,需要的朋友可以参考下
近期用SSM框架写一个项目，登录模块需要生成验证码图片，我把相关的代码写好了之后传到 jsp ，但是图片不显示，查看控
制台显示404，反复查询了一下代码并没有发现任何问题，代码如下：
@Controller
public class ValidateCodeController {
private static final long serialVersionUID = 1L;
private static int WIDTH = 70; // 验证码图片的宽度
private static int HEIGHT = 35; // 验证码图片的高度
@RequestMapping("/validateCode")
public void validateCode(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
HttpSession session = request.getSession();
response.setContentType("image/jpeg");
ServletOutputStream sos = response.getOutputStream();
// 设置浏览器不要缓存该图片
response.setHeader("Pragma", "No-cache");
response.setHeader("Cache-Control", "no-cache");
response.setDateHeader("Expires", 0);
// 创建图片缓存区
BufferedImage image = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);
Graphics g = image.getGraphics(); // 获取画笔
char [] rands = generateCheckCode(); // 产生随机的验证码
// 产生图像
drawBackground(g);
drawRands(g, rands);
// 结束绘画过程，完成图像
g.dispose();
// 将图像输出到客户端
ByteArrayOutputStream bos = new ByteArrayOutputStream();
ImageIO.write(image, "JPEG", bos);
byte [] buf = bos.toByteArray();
response.setContentLength(buf.length);
sos.write(buf);
bos.close();
sos.close();
// 将当前验证码存入 Session 中
session.setAttribute("valicode", new String(rands));
//System.out.println("1:"+request.getSession().getId());
System.out.println(session.getAttribute("valicode"));
}
private void drawRands(Graphics g, char[] rands) {
g.setColor(new Color(41, 41, 41));
g.setFont(new Font(null, Font.ITALIC|Font.BOLD, 18));
g.drawString("" + rands[0], 2, 17);
g.drawString(" " + rands[1], 16, 20);
g.drawString(" " + rands[2], 31, 13);
g.drawString(" " + rands[3], 46, 18);
//System.out.println(rands);
}
private void drawBackground(Graphics g) {
g.setColor(new Color(255, 255, 255));
g.fillRect(0, 0, WIDTH, HEIGHT);
// 随机产生 120 个干扰点
for(int i = 0; i < 120; i++) {
int x = (int) (Math.random() * WIDTH);
int y = (int) (Math.random() * HEIGHT);
int red = (int) (Math.random() * 255);
int green = (int) (Math.random() * 255);
int blue = (int) (Math.random() * 255);
g.setColor(new Color(red, green, blue));
g.drawOval(x, y, 1, 0);
}
}
// 生成四个字符的验证码
private char[] generateCheckCode() {
String chars = "0123456789abcdefghijklmnopqrstuvwxyz";
char [] rands = new char[4];
for(int i = 0; i <4; i++) {
int rand = (int) (Math.random() * 36);
rands[i] = chars.charAt(rand);
}
return rands;
}
}
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