/*
* Copyright 2013-2014 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.github.dactiv.common.utils;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;
import javax.imageio.ImageIO;
/**
* 简单的验证码工具类
*
* @author maurice
*
*/
public class CaptchaUtils {
public static String FONT_FAMILY = "Arial Black";
public static Integer FONT_SIZE = 16;
/**
* 生成图形验证码，并返回code值
*
* @param width 宽度
* @param height 高度
* @param num 验证码位数
* @param out OutputStream
*
* @return String
*/
public static String getCaptcha(int width, int height, int num,
OutputStream out) {
// 防止非负数
width = width > 0 ? width : 60;
height = height > 0 ? height : 18;
// 生成一张新图片
BufferedImage image = new BufferedImage(width, height,
BufferedImage.TYPE_INT_RGB);
Font font = new Font(FONT_FAMILY, Font.PLAIN, FONT_SIZE);
// 绘制图片
Random random = new Random();
Graphics g = image.getGraphics();
g.setColor(getRandColor(200, 250));
g.fillRect(1, 1, width - 1, height - 1);
g.setColor(new Color(102, 102, 103));
g.drawRect(0, 0, width - 1, height - 1);
g.setFont(font);
// 随机生成线条，让图片看起来更加杂乱
g.setColor(getRandColor(160, 200));
for (int i = 0; i < 155; i++) {
int x = random.nextInt(width - 1);
int y = random.nextInt(height - 1);
int x1 = random.nextInt(6) + 1;
int y1 = random.nextInt(12) + 1;
g.drawLine(x, y, x + x1, y + y1);
}
// 该变量用于保存系统生成的随机字符串
String sRand = "";
for (int i = 0; i < num; i++) {
// 取得一个随机字符
String tmp = getRandomChar();
sRand += tmp;
// 将系统随机字符添加到图形验证码图片上
g.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110)));
g.drawString(tmp, FONT_SIZE * i + 5, FONT_SIZE + 5);
}
g.dispose();
try {
ImageIO.write(image, "JPEG", out);
out.close();
} catch (IOException e) {
sRand = null;
e.printStackTrace();
}
return sRand;
}
/**
* 生成随机颜色
*
* @param fc 从随机的颜色位置 (0-255)
* @param bc 到随机的颜色位置（0-255）
*
* @return {@link Color}
*/
public static Color getRandColor(int fc, int bc) {
Random random = new Random();
if (fc > 255)
fc = 255;
if (bc > 255)
bc = 255;
int r = fc + random.nextInt(bc - fc);
int g = fc + random.nextInt(bc - fc);
int b = fc + random.nextInt(bc - fc);
return new Color(r, g, b);
}
/**
* 生成随机字符的方法
*/
public static String getRandomChar() {
int rand = (int) Math.round(Math.random() * 2);
long itmp = 0;
char ctmp = '\u0000';
// 根据rand的值来决定是生成一个大写字母，小写字母和数字
switch (rand) {
// 生成大写字母的情形
case 1:
itmp = Math.round(Math.random() * 25 + 65);
ctmp = (char) itmp;
return String.valueOf(ctmp);
// 生成小写字母的情形
case 2:
itmp = Math.round(Math.random() * 25 + 97);
ctmp = (char) itmp;
return String.valueOf(ctmp);
// 生成数字的情形
default:
itmp = Math.round(Math.random() * 9);
return String.valueOf(itmp);
}
}
}