最近看了PHP写的动画gif验证码，于是用Java实现了类似的，代码不是很良好，将就着看。。
代码包含Gif编码解码四个类，在附件中，自行下载。
import java.awt.*;
import java.io.OutputStream;
import static Randoms.num;
import static Randoms.alpha;
/**
* <p>验证码抽象类,暂时不支持中文</p>
*
* @author: wuhongjun
* @version:1.0
*/
public abstract class Captcha
{
protected Font font = new Font("Verdana", Font.ITALIC|Font.BOLD, 28); // 字体
protected int len = 5; // 验证码随机字符长度
protected int width = 150; // 验证码显示跨度
protected int height = 40; // 验证码显示高度
private String chars = null; // 随机字符串
/**
* 生成随机字符数组
* @return 字符数组
*/
protected char[] alphas()
{
char[] cs = new char[len];
for(int i = 0;i<len;i++)
{
cs[i] = alpha();
}
chars = new String(cs);
return cs;
}
public Font getFont()
{
return font;
}
public void setFont(Font font)
{
this.font = font;
}
public int getLen()
{
return len;
}
public void setLen(int len)
{
this.len = len;
}
public int getWidth()
{
return width;
}
public void setWidth(int width)
{
this.width = width;
}
public int getHeight()
{
return height;
}
public void setHeight(int height)
{
this.height = height;
}
/**
* 给定范围获得随机颜色
* @return Color 随机颜色
*/
protected Color color(int fc, int bc)
{
if (fc > 255)
fc = 255;
if (bc > 255)
bc = 255;
int r = fc + num(bc - fc);
int g = fc + num(bc - fc);
int b = fc + num(bc - fc);
return new Color(r, g, b);
}
/**
* 验证码输出,抽象方法，由子类实现
* @param os 输出流
*/
public abstract void out(OutputStream os);
/**
* 获取随机字符串
* @return string
*/
public String text()
{
return chars;
}
}
png格式验证码
import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import static Randoms.num;
/**
* <p>png格式验证码</p>
*
* @author: wuhongjun
* @version:1.0
*/
public class SpecCaptcha extends Captcha
{
public SpecCaptcha()
{
}
public SpecCaptcha(int width, int height)
{
this.width = width;
this.height = height;
}
public SpecCaptcha(int width, int height, int len){
this(width,height);
this.len = len;
}
public SpecCaptcha(int width, int height, int len, Font font){
this(width,height,len);
this.font = font;
}
/**
* 生成验证码
* @throws java.io.IOException IO异常
*/
@Override
public void out(OutputStream out){
graphicsImage(alphas(), out);
}
/**
* 画随机码图
* @param strs 文本
* @param out 输出流
*/
private boolean graphicsImage(char[] strs, OutputStream out){
boolean ok = false;
try
{
BufferedImage bi = new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
Graphics2D g = (Graphics2D)bi.getGraphics();
AlphaComposite ac3;
Color color ;
int len = strs.length;
g.setColor(Color.WHITE);
g.fillRect(0,0,width,height);
// 随机画干扰的蛋蛋
for(int i=0;i<15;i++){
color = color(150, 250);
g.setColor(color);
g.drawOval(num(width), num(height), 5+num(10), 5+num(10));// 画蛋蛋，有蛋的生活才精彩
color = null;
}
g.setFont(font);
int h = height - ((height - font.getSize()) >>1),
w = width/len,
size = w-font.getSize()+1;
/* 画字符串 */
for(int i=0;i<len;i++)
{
ac3 = AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.7f);// 指定透明度
g.setComposite(ac3);
color = new Color(20 + num(110), 20 + num(110), 20 + num(110));// 对每个字符都用随机颜色
g.setColor(color);
g.drawString(strs[i]+"",(width-(len-i)*w)+size, h-4);
color = null;
ac3 = null;
}
ImageIO.write(bi, "png", out);
out.flush();
ok = true;
}catch (IOException e){
ok = false;
}finally
{
Streams.close(out);
}
return ok;
}
}
Gif验证码类
import Streams;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.OutputStream;
import static Randoms.num;
/**
* <p>Gif验证码类</p>
*
* @author: wuhongjun
* @version:1.0
*/
public class GifCaptcha extends Captcha
{
public GifCaptcha()
{
}
public GifCaptcha(int width,int height){
this.width = width;
this.height = height;
}
public GifCaptcha(int width,int height,int len){
this(width,height);
this.len = len;
}
public GifCaptcha(int width,int height,int len,Font font)
{
this(width,height,len);
this.font = font;
}
@Override
public void out(OutputStream os)
{
try
{
GifEncoder gifEncoder = new GifEncoder(); // gif编码类，这个利用了洋人写的编码类，所有类都在附件中
//生成字符
gifEncoder.start(os);
gifEncoder.setQuality(180);
gifEncoder.setDelay(100);
gifEncoder.setRepeat(0);
BufferedImage frame;
char[] rands =alphas();
Color fontcolor[]=new Color[len];
for(int i=0;i<len;i++)
{
fontcolor[i]=new Color(20 + num(110), 20 + num(110), 20 + num(110));
}
for(int i=0;i<len;i++)
{
frame=graphicsImage(fontcolor, rands, i);
gifEncoder.addFrame(frame);
frame.flush();
}
gifEncoder.finish();
}finally
{
Streams.close(os);
}
}
/**
* 画随机码图
* @param fontcolor 随机字体颜色
* @param strs 字符数组
* @param flag 透明度使用
* @return BufferedImage
*/
private BufferedImage graphicsImage(Color[] fontcolor,char[] strs,int flag)
{
BufferedImage image = new BufferedImage(width, height,BufferedImage.TYPE_INT_RGB);
//或得图形上下文
//Graphics2D g2d=image.createGraphics();
Graphics2D g2d = (Graphics2D)image.getGraphics();
//利用指定颜色填充背景
g2d.setColor(Color.WHITE);
g2d.fillRect(0, 0, width, height);
AlphaComposite ac3;
int h = height - ((height - font.getSize()) >>1) ;
int w = width/len;
g2d.setFont(font);
for(int i=0;i<len;i++)
{
ac3 = AlphaComposite.getInstance(AlphaComposite.SRC_OVER, getAlpha(flag, i));
g2d.setComposite(ac3);
g2d.setColor(fontcolor[i]);
g2d.drawOval(num(width), num(height), 5+num(10), 5+num(10));
g2d.drawString(strs[i]+"", (width-(len-i)*w)+(w-font.getSize())+1, h-4);
}
g2d.dispose();
return image;
}
/**
* 获取透明度,从0到1,自动计算步长
* @return float 透明度
*/
private float getAlpha(int i,int j)
{
int num = i+j;
float r = (float)1/len,s = (len+1) * r;
return num > len ? (num *r - s) : num * r;
}
}
Streams IO工具类
public class Streams
{
/**
* 关闭输入流
* @param in 输入流
*/
public static void close(InputStream in) {
if (in != null) {
try {
in.close();
} catch (IOException ioex) {
// ignore
}
}
}
/**
* 关闭输出流
* @param out 输出流
*/
public static void close(OutputStream out) {
if (out != null) {
try {
out.flush();
} catch (IOException ioex) {
// ignore
}
try {
out.close();
} catch (IOException ioex) {
// ignore
}
}
}
}
Randoms 随机数工具类
/**
* <p>随机工具类</p>
*
* @author: wuhongjun
* @version:1.0
*/
public class Randoms
{
private static final Random RANDOM = new Random();
//定义验证码字符.去除了O和I等容易混淆的字母
public static final char ALPHA[]={'A','B','C','D','E','F','G','H','G','K','M','N','P','Q','R','S','T','U','V','W','X','Y','Z'
,'a','b','c','d','e','f','g','h','i','j','k','m','n','p','q','r','s','t','u','v','w','x','y','z','2','3','4','5','6','7','8','9'};
/**
* 产生两个数之间的随机数
* @param min 小数
* @param max 比min大的数
* @return int 随机数字
*/
public static int num(int min, int max)
{
return min + RANDOM.nextInt(max - min);
}
/**
* 产生0--num的随机数,不包括num
* @param num 数字
* @return int 随机数字
*/
public static int num(int num)
{
return RANDOM.nextInt(num);
}
public static char alpha()
{
return ALPHA[num(0, ALPHA.length)];
}
}
Gif编码解码类，总共四个.zip ~ 16KB
http://download.csdn.net/detail/qilixiang012/8311995
PNG格式验证码.png
GIF动画验证码.gif
使用说明,web请用response的输出流
public static void main(String[] args) throws FileNotFoundException
{
Captcha captcha = new SpecCaptcha(150,40,5);// png格式验证码
captcha.out(new FileOutputStream("E:/1.png"));
captcha = new GifCaptcha(150,40,5);// gif格式动画验证码
captcha.out(new FileOutputStream("E:/1.gif"));
}