cn.songxinqiang.tool.RandomImage Maven / Gradle / Ivy

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/**
 * Copyright 2014 阿信([email protected])
 * 
 * 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 cn.songxinqiang.tool;

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.util.Random;

import javax.imageio.ImageIO;

/**
 * 验证码图片生成，可指定图片的尺寸和干扰线等参数
 * 
 * @author 宋信强--2014年9月10日[email protected]
 *
 */
public class RandomImage {

    private Random random = new Random();

    private Font font = new Font("Fixedsys", Font.CENTER_BASELINE, 18);

    /**
     * 根据指定的字符和大小生成随机验证码图片
     * 
     * @param code
     *            需要绘制到图片上的字符数组
     * @param width
     *            图片宽度
     * @param height
     *            图片高度
     * @param line
     *            干扰线数量
     * @return 图片的输入流
     */
    public ByteArrayInputStream getImage(char[] code, int width, int height, int line) {
        // BufferedImage类是具有缓冲区的Image类,Image类是用于描述图像信息的类
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_BGR);
        Graphics g = image.getGraphics();
        g.fillRect(0, 0, width, height);
        g.setFont(new Font("Times New Roman", Font.ROMAN_BASELINE, 18));
        g.setColor(getRandColor(110, 133));
        // 绘制干扰线
        for (int i = 0; i < line; i++) {
            drowLine(g, width, height);
        }
        // 绘制随机字符
        for (int i = 0; i < code.length; i++) {
            drowChar(g, width / code.length * i, random.nextInt(height / 3) + height / 3, code[i]);
        }
        g.dispose();

        return convertImageToStream(image);
    }

    /**
     * 将BufferedImage转换成ByteArrayInputStream
     * 
     * @param image
     *            图片
     * @return ByteArrayInputStream 流
     */
    private ByteArrayInputStream convertImageToStream(BufferedImage image) {
        ByteArrayInputStream inputStream = null;
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        try {
            ImageIO.write(image, "JPEG", bos);
            byte[] bts = bos.toByteArray();
            inputStream = new ByteArrayInputStream(bts);
        } catch (IOException e1) {}
        return inputStream;
    }

    /*
     * 获得颜色
     */
    private Color getRandColor(int fc, int bc) {
        if (fc > 255) {
            fc = 255;
        }
        if (bc > 255) {
            bc = 255;
        }
        int r = fc + random.nextInt(bc - fc - 16);
        int g = fc + random.nextInt(bc - fc - 14);
        int b = fc + random.nextInt(bc - fc - 18);
        return new Color(r, g, b);
    }

    /*
     * 绘制字符
     */
    private char drowChar(Graphics g, int x, int y, char code) {
        g.setFont(font);
        g.setColor(getRandColor(10, 200));
        g.translate(random.nextInt(3), random.nextInt(3));
        g.drawString(code + "", x, y);
        return code;
    }

    /*
     * 绘制干扰线
     */
    private void drowLine(Graphics g, int width, int height) {
        int x = random.nextInt(width);
        int y = random.nextInt(height);
        int xl = random.nextInt(width / 2);
        int yl = random.nextInt(height / 2);
        g.drawLine(x, y, x + xl, y + yl);
    }
}