package com.feifei.util;

import java.awt.Color;

import java.awt.Font;

import java.awt.Graphics;

import java.awt.image.BufferedImage;

import java.io.ByteArrayInputStream;

import java.io.ByteArrayOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.util.HashMap;

import java.util.Map;

import java.util.Random;

import com.sun.image.codec.jpeg.JPEGCodec;

import com.sun.image.codec.jpeg.JPEGImageEncoder;

/**

* 生成验证码图片工具类

*/

public final class ImageUtil {

private static final char[] chars = { '0', '1', '2', '3', '4', '5', '6',

'7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I' };

private static final int SIZE = 4;

private static final int LINES = 5;

private static final int WIDTH = 80;

private static final int HEIGHT = 40;

private static final int FONT_SIZE = 30;

/**

* 创建一个验证码图片，其中Map的key封装了 验证码字符串，Map的value封装了验证码图片。

*/

public static Map<String, BufferedImage> createImage() {

StringBuffer sb = new StringBuffer();

BufferedImage image = new BufferedImage(WIDTH, HEIGHT,

BufferedImage.TYPE_INT_RGB);

Graphics graphic = image.getGraphics();

graphic.setColor(Color.LIGHT_GRAY);

graphic.fillRect(0, 0, WIDTH, HEIGHT);

Random ran = new Random();

// 画随机字符

for (int i = 1; i <= SIZE; i++) {

int r = ran.nextInt(chars.length);

graphic.setColor(getRandomColor());

graphic.setFont(new Font(null, Font.BOLD + Font.ITALIC, FONT_SIZE));

graphic.drawString(chars[r] + "", (i - 1) * WIDTH / SIZE,

HEIGHT / 2);

sb.append(chars[r]);// 将字符保存，存入Session

}

// 画干扰线

for (int i = 1; i <= LINES; i++) {

graphic.setColor(getRandomColor());

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

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

}

Map<String, BufferedImage> map = new HashMap<String, BufferedImage>();

map.put(sb.toString(), image);

return map;

}

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 InputStream getInputStream(BufferedImage image)

throws IOException {

ByteArrayOutputStream bos = new ByteArrayOutputStream();

JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(bos);

encoder.encode(image);

byte[] imageBts = bos.toByteArray();

InputStream in = new ByteArrayInputStream(imageBts);

return in;

}

}