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Posted on 2011-04-16 13:49 IceWee 阅读(294) 评论(0) 编辑 收藏 所属分类: Java
仿照腾讯的Token写的验证码生成程序
Java类代码：
 package icewee.image;
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.geom.Line2D;
import java.awt.image.BufferedImage;
import java.util.Random;
  public class TokenUtil  {
private static final String base = "23456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefhijklmnpqrstuvwxyz";
private static final int length = base.length();
  public static BufferedImage createTokenImage(int width, int height, String randomCode) {
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
Graphics2D g = image.createGraphics();
Random random = new Random();
g.setColor(new Color(230, 230, 250)); // 设置背景色
g.fillRect(0, 0, width, height); // 填充背景
g.setColor(Color.BLACK); // 绘制边缘
g.drawRect(-1, -1, width + 1, height + 1);
g.setColor(Color.GRAY); // 设置字体,随机选择字体,暂设置8种字体
Font font = new Font((new String[] { "Arial", "Arial Black", "Arial Italic", "Courier New", "Courier New Bold Italic", "Courier New Italic", "Franklin Gothic Medium", "Franklin Gothic Medium Italic" })[random.nextInt(8)], Font.PLAIN, 30);
// g.setStroke(new BasicStroke((float)(Math.random()), BasicStroke.CAP_BUTT, BasicStroke.JOIN_BEVEL));
g.setFont(font); // 定义字体颜色范围
int red = random.nextInt(160), green = random.nextInt(50), blue = random.nextInt(50); // 定义一个无干扰线区间和一个起始位置
int nor = random.nextInt(50), rsta = random.nextInt(131); // 绘制干扰正弦曲线 M:曲线平折度, D:Y轴常量 V:X轴焦距
int M = random.nextInt(15) + 5, D = random.nextInt(23) + 15, V = random.nextInt(5) + 1;
double x = 0.0;
double y = M * Math.sin(Math.toRadians(V * x)) + D;
double px, py;
for (int i = 0; i < 131; i++) {
px = x + 1;
py = M * Math.sin(Math.toRadians(V * px)) + D;
if (rsta < i && i < (rsta + nor))
g.setColor(new Color(230, 230, 250));
else
g.setColor(new Color(red, green, blue)); // 随机设置像素点宽带(线宽)
g.setStroke(new BasicStroke((float) (Math.random() + 1.5f)));
g.draw(new Line2D.Double(x, y, px, py));
x = px;
y = py;
 }
char[] codes = randomCode.toCharArray();
for (int i = 0; i < codes.length; i++) { // 旋转图形
int degree = (random.nextInt(20) - 10) % 360;
double ang = degree * 0.0174532925; // 将角度转为弧度
g.rotate(ang, width / 2, height / 2);
g.setColor(new Color(red, green, blue));
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
int gr = random.nextInt(8);
g.drawString(String.valueOf(codes[i]), 24 * i + 10 + gr, 38);
}
g.dispose();
return image;
}
public static String createRandomCode(int size, int width, int height) {
StringBuffer randomCode = new StringBuffer();
for (int i = 0; i < size; i++) {
Random random = new Random();
int start = random.nextInt(length);
String strRand = base.substring(start, start + 1);
randomCode.append(strRand);
}
return randomCode.toString();
}
 }
JSP页面：
<%@page contentType="image/jpeg" pageEncoding="GBK"%>
<%@page import="java.awt.image.BufferedImage"%>
<%@page import="javax.imageio.ImageIO"%>
<%@page import="com.icesoft.image.TokenUtil"%>
<%
//设置页面不缓存
response.setHeader("Pragma", "No-cache");
response.setHeader("Cache-Control", "no-cache");
response.setDateHeader("Expires", 0);
int width = 120, height = 50;
String randomCode = TokenUtil.createRandomCode(4, width, height);
System.out.println("生成的随机码：" + randomCode);
BufferedImage image = TokenUtil.createTokenImage(width, height, randomCode);
ImageIO.write(image, "JPEG", response.getOutputStream());
response.flushBuffer();
out.clear();
out = pageContext.pushBody();
%>
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