java web 验证码-数字不变形

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
@RequestMapping("randomCheckCode")
public class RandomCheckCodeController {

// 验证码图片的宽度。
private int width = 60;
// 验证码图片的高度。
private int height = 20;
// 验证码字符个数
private int codeCount = 4;
// 字体高度
private int fontHeight;
//字体的x坐标
private int x = 0;
private int y = 0;
private static Random random = new Random();
　　//去除0、1、i、l等容易混淆字符
public static final String VERIFY_CODES = "23456789abcdefghjkmnprstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ";

private static Color getRandColor(int fc, int bc) {
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);
}

/**
* 初始化图片属性
*/
public void init() {
x = width / (codeCount );
fontHeight = height - 2;
y = height - 4;
}
@RequestMapping("generate")
public void generateNumber(HttpServletRequest request,
HttpServletResponse resp) {
init();
// 定义图像buffer
BufferedImage buffImg = new BufferedImage(width, height,
BufferedImage.TYPE_INT_RGB);
Graphics2D g = buffImg.createGraphics();
// 填充背景色
//        g.setColor(getRandColor(200, 250));
g.setColor(Color.WHITE);
g.fillRect(0, 0, width, height);
// 创建字体，字体的大小应该根据图片的高度来定
Font font = new Font("Fixedsys", Font.PLAIN, fontHeight);
// 设置字体
g.setFont(font);
// 画一个边框
g.setColor(Color.GRAY);
g.drawRect(0, 0, width - 1, height - 1);
// 随机产生160条干扰线，使图象中的验证码不易被其它程序探测到
g.setColor(Color.BLACK);
for (int i = 0; i < 10; i++) {
int x = random.nextInt(width);
int y = random.nextInt(height);
int xl = random.nextInt(12);
int yl = random.nextInt(12);
g.drawLine(x, y, x + xl, y + yl);
}
// randomCode用于保存随机产生的验证码，以便用户登录后进行验证
StringBuffer randomCode = new StringBuffer();
int red = 0, green = 0, blue = 0;
// 随机产生codeCount数字的验证码。
for (int i = 0; i < codeCount; i++) {
// 得到随机产生的验证码数字
char ch = VERIFY_CODES.charAt(random.nextInt(VERIFY_CODES.length()));
// 产生随机的颜色分量来构造颜色值，这样输出的每位数字的颜色值都将不同
red = random.nextInt(255);
green = random.nextInt(255);
blue = random.nextInt(255);
// 用随机产生的颜色将验证码绘制到图像中
g.setColor(new Color(red, green, blue));
g.drawString(String.valueOf(ch),  i*x+1, y);
// 将产生的四个随机数组合在一起
randomCode.append(ch);
}
// 将四位数字的验证码保存到Session中
HttpSession session = request.getSession();
session.setAttribute("validateCode", randomCode.toString());
// 禁止图像缓存
resp.setHeader("Pragma", "no-cache");
resp.setHeader("Cache-Control", "no-cache");
resp.setDateHeader("Expires", 0);
resp.setContentType("image/jpeg");
// 将图像输出到Servlet输出流中
try {
ServletOutputStream sos = resp.getOutputStream();
ImageIO.write(buffImg, "jpeg", resp.getOutputStream());
sos.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}

<img src="${ctx }/randomCheckCode/generate1?t=1" id="CreateCheckCode" align="middle" onclick="reloadPic()">

<script type="text/javascript">
function reloadPic() {
document.getElementById("checkCode").src = document.getElementById("checkCode").src + "1";
}
</script>