package org.util;

import javax.imageio.ImageIO;

import java.awt.*;

import java.awt.image.BufferedImage;

import java.awt.image.CropImageFilter;

import java.awt.image.FilteredImageSource;

import java.awt.image.ImageFilter;

import java.io.File;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.OutputStream;

public class ImgTools {

    /**

     * 按照 宽高 比例压缩

     *

     * @param img

     * @param width

     * @param height

     * @param out

     * @throws IOException

     */

    public static void thumbnail_w_h(File img, int width, int height,

            OutputStream out) throws IOException {

        BufferedImage bi = ImageIO.read(img);

        double srcWidth = bi.getWidth(); // 源图宽度

        double srcHeight = bi.getHeight(); // 源图高度

        double scale = 1;

        if (width > 0) {

            scale = width / srcWidth;

        }

        if (height > 0) {

            scale = height / srcHeight;

        }

        if (width > 0 && height > 0) {

            scale = height / srcHeight < width / srcWidth ? height / srcHeight

                    : width / srcWidth;

        }

        thumbnail(img, (int) (srcWidth * scale), (int) (srcHeight * scale), out);

    }

    /**

     * 按照固定宽高原图压缩

     *

     * @param img

     * @param width

     * @param height

     * @param out

     * @throws IOException

     */

    public static void thumbnail(File img, int width, int height,

            OutputStream out) throws IOException {

        BufferedImage BI = ImageIO.read(img);

        Image image = BI.getScaledInstance(width, height, Image.SCALE_SMOOTH);

        BufferedImage tag = new BufferedImage(width, height,

                BufferedImage.TYPE_INT_RGB);

        Graphics g = tag.getGraphics();

        g.setColor(Color.RED);

        g.drawImage(image, 0, 0, null); // 绘制处理后的图

        g.dispose();

        ImageIO.write(tag, "JPEG", out);

    }

    /**

     * 按照宽高裁剪

     *

     * @param srcImageFile

     * @param destWidth

     * @param destHeight

     * @param out

     */

    public static void cut_w_h(File srcImageFile, int destWidth,

            int destHeight, OutputStream out) {

        cut_w_h(srcImageFile, 0, 0, destWidth, destHeight, out);

    }

    public static void cut_w_h(File srcImageFile, int x, int y, int destWidth,

            int destHeight, OutputStream out) {

        try {

            Image img;

            ImageFilter cropFilter;

            // 读取源图像

            BufferedImage bi = ImageIO.read(srcImageFile);

            int srcWidth = bi.getWidth(); // 源图宽度

            int srcHeight = bi.getHeight(); // 源图高度

            if (srcWidth >= destWidth && srcHeight >= destHeight) {

                Image image = bi.getScaledInstance(srcWidth, srcHeight,

                        Image.SCALE_DEFAULT);

                cropFilter = new CropImageFilter(x, y, destWidth, destHeight);

                img = Toolkit.getDefaultToolkit().createImage(

                        new FilteredImageSource(image.getSource(), cropFilter));

                BufferedImage tag = new BufferedImage(destWidth, destHeight,

                        BufferedImage.TYPE_INT_RGB);

                Graphics g = tag.getGraphics();

                g.drawImage(img, 0, 0, null); // 绘制截取后的图

                g.dispose();

                // 输出为文件

                ImageIO.write(tag, "JPEG", out);

            }

        } catch (Exception e) {

            e.printStackTrace();

        }

    }// #cut_w_h

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

        File img = new File("e:\\a\\a.jpg");

        FileOutputStream fos = new FileOutputStream("e:\\a\\b.jpg");

        // ImgTools.thumbnail(img, 100, 100, fos);

        // ImgTools.cut_w_h(img, 230, 200, fos);

        ImgTools.thumbnail_w_h(img, 100, 0, fos);

    }

}