java工具类——验证码（VerifyCode）

package www.zhidisoft.com.work426.verifycode; import java.awt.BasicStroke; import java.awt.Color; import java.awt.Font; import java.awt.Graphics2D; import java.awt.image.BufferedImage; import java.io.FileNotFoundException; import java.io.IOException; import java.io.OutputStream; import java.util.Random; import javax.imageio.ImageIO; public class VerifyCode { private int w = 70; private int h = 35; private Random r = new Random(); // 定义有那些字体 private String[] fontNames = { "宋体", "华文楷体", "黑体", "微软雅黑", "楷体_GB2312" }; // 定义有那些验证码的随机字符 private String codes = "23456789abcdefghjkmnopqrstuvwxyzABCDEFGHJKLMNOPQRSTUVWXYZ"; // 生成背景色 private Color bgColor = new Color(30, 30, 30); // 用于gettext 方法 获得生成的验证码文本 private String text; // 生成随机颜色 private Color randomColor() { int red = r.nextInt(150); int green = r.nextInt(150); int blue = r.nextInt(150); return new Color(red, green, blue); } // 生成随机字体 private Font randomFont() { int index = r.nextInt(fontNames.length); String fontName = fontNames[index]; int style = r.nextInt(4); int size = r.nextInt(5) + 24; return new Font(fontName, style, size); } // 画干扰线 private void drawLine(BufferedImage image) { int num = 3; Graphics2D g2 = (Graphics2D) image.getGraphics(); for (int i = 0; i < num; i++) { int x1 = r.nextInt(w); int y1 = r.nextInt(h); int x2 = r.nextInt(w); int y2 = r.nextInt(h); g2.setStroke(new BasicStroke(1.5F));// 不知道 g2.setColor(Color.blue); g2.drawLine(x1, y1, x2, y2); } } // 得到codes的长度内的随机数 并使用charAt 取得随机数位置上的codes中的字符 private char randomChar() { int index = r.nextInt(codes.length()); return codes.charAt(index); } // 创建一张验证码的图片 public BufferedImage createImage() { BufferedImage image = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB); Graphics2D g2 = (Graphics2D) image.getGraphics(); StringBuilder sb = new StringBuilder(); // 向图中画四个字符 for (int i = 0; i < 4; i++) { String s = randomChar() + ""; sb.append(s); float x = i * 1.0F * w / 4; g2.setFont(randomFont()); g2.setColor(randomColor()); g2.drawString(s, x, h - 5); } this.text = sb.toString(); drawLine(image); // 返回图片 return image; } // 得到验证码的文本 后面是用来和用户输入的验证码 检测用 public String getText() { return text; } // 定义输出的对象和输出的方向 public static void output(BufferedImage bi, OutputStream fos) throws FileNotFoundException, IOException { ImageIO.write(bi, "JPEG", fos); } }