图片验证码

package com.util;


import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;
import javax.imageio.ImageIO;


public final class ImageUtil {


// 验证码字符集
private static final char[] chars = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E',
'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z' };
// 字符数量
private static final int SIZE = 4;
// 干扰线数量
private static final int LINES = 5;
// 宽度
private static final int WIDTH = 80;
// 高度
private static final int HEIGHT = 40;
// 字体大小
private static final int FONT_SIZE = 30;


/**
* 生成随机验证码及图片 返回的数组中，第1个值是验证码， 第2个值是图片。
*/
public static Object[] createImage() {
StringBuffer sb = new StringBuffer();
// 1.创建空白图片
BufferedImage image = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);
// 2.获取图片画笔
Graphics graphic = image.getGraphics();
// 3.设置画笔颜色
graphic.setColor(Color.LIGHT_GRAY);
// 4.绘制矩形背景
graphic.fillRect(0, 0, WIDTH, HEIGHT);
// 5.画随机字符
Random ran = new Random();
for (int i = 0; i < SIZE; i++) {
// 取随机字符索引
int n = ran.nextInt(chars.length);
// 设置随机颜色
graphic.setColor(getRandomColor());
// 设置字体大小
graphic.setFont(new Font(null, Font.BOLD +


Font.ITALIC, FONT_SIZE));
// 画字符
graphic.drawString(chars[n] + "", i * WIDTH / SIZE,


HEIGHT / 2);
// 记录字符
sb.append(chars[n]);
}
// 6.画干扰线
for (int i = 0; i < LINES; i++) {
// 设置随机颜色
graphic.setColor(getRandomColor());
// 随机画线
graphic.drawLine(ran.nextInt(WIDTH),


ran.nextInt(HEIGHT), ran.nextInt(WIDTH),


ran.nextInt(HEIGHT));
}
// 7.返回验证码和图片
return new Object[] { sb.toString(), image };
}


/**
* 随机取色
*/
public static Color getRandomColor() {
Random ran = new Random();
Color color = new Color(ran.nextInt(256), ran.nextInt(256), ran.nextInt(256));
return color;
}


public static void main(String[] args) throws IOException {


Object[] objs = createImage();
BufferedImage image = (BufferedImage) objs[1];
OutputStream os = new FileOutputStream("d:/1.png");
ImageIO.write(image, "png", os);
os.close();

}

}