com.yixan.tools.common.util.ImageUtil Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of yixan-tools-common Show documentation
There is a newer version: 3.7.1
package com.yixan.tools.common.util;

import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Iterator;

import javax.imageio.ImageIO;
import javax.imageio.ImageReader;
import javax.imageio.stream.ImageInputStream;

import net.coobird.thumbnailator.Thumbnails;
import net.coobird.thumbnailator.Thumbnails.Builder;
import net.coobird.thumbnailator.geometry.Positions;

/**
 * 图片工具
 *
 * @author zhaohuihua
 */
public class ImageUtil {

    /**
     * 生成缩略图

     * 截取图片的中间部分(不产生变形)

     * 如3000x2000生成100x100的缩略图

     * 先截取中间的2000x2000的部分, 再缩小为100x100
     *
     * @param width
     * @param height
     * @throws IOException
     */
    public static byte[] thumbnail(byte[] bytes, int width, int height) throws IOException {
        ByteArrayInputStream is = new ByteArrayInputStream(bytes);
        return thumbnail(is, width, height);
    }

    /**
     * 生成缩略图

     * 截取图片的中间部分(不产生变形)

     * 如3000x2000生成100x100的缩略图

     * 先截取中间的2000x2000的部分, 再缩小为100x100
     *
     * @param width
     * @param height
     * @throws IOException
     */
    public static byte[] thumbnail(InputStream is, int width, int height) throws IOException {
        ByteArrayOutputStream os = new ByteArrayOutputStream();
        thumbnail(is, os, width, height);
        return os.toByteArray();
    }

    /**
     * 生成缩略图

     * 截取图片的中间部分(不产生变形)

     * 如3000x2000生成100x100的缩略图

     * 先截取中间的2000x2000的部分, 再缩小为100x100
     *
     * @param width 缩放后的宽度, 0表示自动计算
     * @param height 缩放后的宽度, 0表示自动计算
     * @throws IOException
     */
    public static void thumbnail(InputStream is, OutputStream os, int width, int height) throws IOException {
        ImageInputStream iis = ImageIO.createImageInputStream(is);
        Iterator iterator = ImageIO.getImageReaders(iis);
        ImageReader reader = iterator.next();
        reader.setInput(iis, true);
        String imageType = reader.getFormatName();
        BufferedImage image = reader.read(0);

        int w = image.getWidth();
        int h = image.getHeight();

        if (width > 0 && height <= 0) {
            height = (int) (1.0 * h / w * width);
        } else if (width <= 0 && height > 0) {
            width = (int) (1.0 * w / h * height);
        } else if (width <= 0 && height <= 0) {
            width = w;
            height = h;
        }

        double wscale = 1.0 * width / w;
        double hscale = 1.0 * height / h;

        double scale = height / wscale > h ? hscale : wscale;

        int nw = (int) (width / scale);
        int nh = (int) (height / scale);

        Builder builder = Thumbnails.of(image);
        builder.scale(scale);
        builder.sourceRegion(Positions.CENTER, nw, nh);

        builder.outputFormat(imageType).toOutputStream(os);
    }

    public static void main(String[] args) throws IOException {
        int width = 400;
        int height = 400;

        String folder = "D:/image/";
        // System.out.println(Arrays.toString(ImageIO.getWriterFormatNames()));
        String[] files = new String[] { "1.png", "2.png", "he.jpg", "hw.jpg" };
        for (String src : files) {
            int index = src.lastIndexOf('.');
            String dest = src.substring(0, index) + "." + width + "x" + height + src.substring(index);

            try (InputStream is = new FileInputStream(new File(folder + src));
                    OutputStream os = new FileOutputStream(new File(folder + dest))) {
                thumbnail(is, os, width, height);
            }
        }

    }
}