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package cn.wisenergy.chnmuseum.party.common.checkcode;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
/**
* <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 String 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();
return String.valueOf(rands);
} finally {
try {
os.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
/**
* 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;
}
}