验证码生成器模版

 VCodeGenerator.java

package util;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;

import javax.imageio.ImageIO;
public class VCodeGenerator {
    private int width=160;
    private int height=60;
    private int charCnt=4;
    private int disturbLineNum = 10;

    final private char[] chars = "2345678ABCDEFGHJKLMPQRSTUVWXYabcdefhkmnqrstuvwx"
        .toCharArray();
    private static String[] fontNames = new String[] { "Courier", "Arial",
        "Verdana", "Georgia", "Times", "Tahoma" };
    private static int[] fontStyle = new int[] { Font.PLAIN, Font.BOLD,Font.ITALIC, Font.BOLD | Font.ITALIC };


    private OutputStream os;
    
    public VCodeGenerator(OutputStream os) {//一参构造函数
        this.os = os;
    }
    public VCodeGenerator(int width, int height, int charCnt, OutputStream os) {//四参构造函数
        super();
        this.width = width;
        this.height = height;
        this.charCnt = charCnt;
        this.os = os;
    }
    
    public String drawCode() throws IOException {
        BufferedImage bi = new BufferedImage(this.width, this.height,
                BufferedImage.TYPE_INT_RGB);
        Graphics2D g = bi.createGraphics();
        g.setColor(new Color(245, 245, 245));//背景色
        g.fillRect(0, 0, this.width, this.height);

        drawDisturbLine(g);

        BufferedImage[] bis = new BufferedImage[charCnt];
        char[] codes = generateCode();
        for (int i = 0; i < charCnt; i++) {
            bis[i] = generateBuffImg(codes[i]);
            g.drawImage(bis[i], null, (int) (this.height * 0.6) * i, 0);
        }

        g.dispose();

        ImageIO.write(bi, "gif", os);
        return new String(codes);
    }
    private BufferedImage generateBuffImg(char c) {
        String tmp = Character.toString(c);
        Color forecolor = getRandomColor();
        Color backcolor = new Color(255, 255, 255, 0);
        String fontName = getRandomFontName();
        int fontStyle = getRandomStyle();
        int fontSize = getRandomSize();
        int strX = (this.height - fontSize) / 2;
        int strY = (this.height - fontSize) / 2 + fontSize;
        double arch = getRandomArch();

        BufferedImage ret = new BufferedImage(this.height, this.height,
                BufferedImage.TYPE_INT_ARGB);
        Graphics2D g = ret.createGraphics();
        g.setColor(backcolor);
        g.fillRect(0, 0, this.height, this.height);

        g.setColor(forecolor);
        g.setFont(new Font(fontName, fontStyle, fontSize));
        g.rotate(arch, this.height / 2, this.height / 2);
        g.drawString(tmp, strX, strY);

        g.dispose();
        return ret;
    }

    private double getRandomArch() {
        return ((int) (Math.random() * 1000) % 2 == 0 ? -1 : 1) * Math.random();
    }

    private Color getRandomColor() {
        int r = (int) (Math.random() * 10000) % 200;
        int g = (int) (Math.random() * 10000) % 200;
        int b = (int) (Math.random() * 10000) % 200;
        return new Color(r, g, b);
    }

    private String getRandomFontName() {
        int pos = (int) (Math.random() * 10000) % (fontNames.length);
        return fontNames[pos];
    }

    private int getRandomStyle() {
        int pos = (int) (Math.random() * 10000) % (fontStyle.length);
        return fontStyle[pos];
    }

    private int getRandomSize() {
        int max = (int) (this.height * 0.9);
        int min = (int) (this.height * 0.6);
        return (int) (Math.random() * 10000) % (max - min + 1) + min;
    }

    private char[] generateCode() {
        char[] ret = new char[charCnt];
        for (int i = 0; i < charCnt; i++) {
            int letterPos = (int) (Math.random() * 10000) % (chars.length);
            ret[i] = chars[letterPos];
        }
        return ret;
    }
    
    private void drawDisturbLine(Graphics2D graphics) {
        for (int i = 0; i < disturbLineNum; i++) {
            graphics.setColor(getRandomColor());
            int x = (int) (Math.random() * 10000) % (this.width + 1) + 1;
            int x1 = (int) (Math.random() * 10000) % (this.width + 1) + 1;
            int y = (int) (Math.random() * 10000) % (this.height + 1) + 1;
            int y1 = (int) (Math.random() * 10000) % (this.height + 1) + 1;
            graphics.drawLine(x, y, x1, y1);
        }

    }

    public static void main(String[] args) throws IOException {
        FileOutputStream fos = new FileOutputStream("d:/tmp.gif");
        VCodeGenerator vg = new VCodeGenerator(80,30,4,fos);
        String a=vg.drawCode();
        System.out.print("\n"+a);
/* 新建一个servlet，代码如下：（验证码直接调用该servlet）
 * OutputStream os=response.getOutputStream();
        VCodeGenerator vg=new VCodeGenerator(os);
        String vcode=vg.drawCode();
        os.close();
        request.getSession().setAttribute("vcode", vcode);
        System.out.print("\n"+vcode);
  *jsp中获取：
          <tr> <td height="60">
            <img src="servlet/getVcode?ts="+new Date().getTime() id="imgVcode"/>
          </td> </tr>
        <tr>
          <td align="center" valign="middle" height="20" style="color:blue">若看不清，点图片换一张</td>
        </tr>
   *js中控制    
    //绑定验证码图片框单击事件实现更换验证码
    $("div.validateCodeDiv").click(function(event){
        changeCode();
        window.event.cancelBubble = true;//防止冒泡事件
    });
        function changeCode(){
    $("#imgVcode").attr("src","servlet/getVcode?ts="+new Date().getTime() );    
}
*/
    }
}