利用Thumbnails，java图片压缩，转换工具类

Thumbnails是谷歌的一个图片压缩处理开源库。利用这个库可以非常容易的做图片处理。这里整理了一些方法。直接看代码吧。

先添加jar支持

		
			net.coobird
			thumbnailator
			0.4.8
		

工具类，直接可用

/*
 * 文件名：ImageUtil.java
 * 描述：
 * 修改人：gogym
 * 修改时间：2018年11月10日
 * 跟踪单号：
 * 修改单号：
 * 修改内容：
 */

import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import javax.imageio.ImageIO;

import org.apache.commons.io.output.ByteArrayOutputStream;

import net.coobird.thumbnailator.Thumbnails;
import net.coobird.thumbnailator.geometry.Position;

public class ImageUtil {
	/**
	 * 指定大小进行缩放 若图片横比width小，高比height小，不变 若图片横比width小，高比height大，高缩小到height，图片比例不变
	 * 若图片横比width大，高比height小，横缩小到width，图片比例不变
	 * 若图片横比width大，高比height大，图片按比例缩小，横为width或高为height
	 *
	 * @param source
	 *            输入源
	 * @param output
	 *            输出源
	 * @param width
	 *            宽
	 * @param height
	 *            高
	 * @throws IOException
	 */
	public static void imgThumb(String source, String output, int width,
			int height, float quality) throws IOException {
		Thumbnails.of(source).size(width, height).outputQuality(quality)
				.outputFormat("jpg").toFile(output);
	}

	public static OutputStream imgThumbOutputStream(String source, int width,
			int height, float quality) throws IOException {

		OutputStream os = new ByteArrayOutputStream();
		Thumbnails.of(source).size(width, height).outputQuality(quality)
				.outputFormat("jpg").toOutputStream(os);
		return os;
	}

	/**
	 * 指定大小进行缩放
	 *
	 * @param source
	 *            输入源
	 * @param output
	 *            输出源
	 * @param width
	 *            宽
	 * @param height
	 *            高
	 * @throws IOException
	 */
	public static void imgThumb(File source, String output, int width,
			int height, float quality) throws IOException {
		Thumbnails.of(source).size(width, height).outputQuality(quality)
				.outputFormat("jpg").toFile(output);
	}

	/**
	 * 按照比例进行缩放
	 *
	 * @param source
	 *            输入源
	 * @param output
	 *            输出源
	 * @throws IOException
	 */
	public static void imgScale(String source, String output, double scale)
			throws IOException {
		Thumbnails.of(source).scale(scale).outputFormat("jpg").toFile(output);
	}

	public static void imgScale(File source, String output, double scale)
			throws IOException {
		Thumbnails.of(source).scale(scale).outputFormat("jpg").toFile(output);
	}

	public static OutputStream imgScaleOutputStream(File source, double scale)
			throws IOException {
		OutputStream os = new ByteArrayOutputStream();
		Thumbnails.of(source).scale(scale).outputFormat("jpg")
				.toOutputStream(os);
		return os;
	}

	public static byte[] imgScaleByte(byte[] source, double scale)
			throws IOException {

		ByteArrayOutputStream os = new ByteArrayOutputStream();
		InputStream input = new ByteArrayInputStream(source);
		Thumbnails.of(input).scale(scale).outputFormat("jpg")
				.toOutputStream(os);
		return os.toByteArray();
	}

	/**
	 * 不按照比例，指定大小进行缩放
	 *
	 * @param source
	 *            输入源
	 * @param output
	 *            输出源
	 * @param width
	 *            宽
	 * @param height
	 *            高
	 * @param keepAspectRatio
	 *            默认是按照比例缩放的,值为false 时不按比例缩放
	 */
	public static void imgNoScale(String source, String output, int width,
			int height, boolean keepAspectRatio) throws IOException {
		Thumbnails.of(source).size(width, height)
				.keepAspectRatio(keepAspectRatio).outputFormat("jpg")
				.toFile(output);
	}

	public static void imgNoScale(File source, String output, int width,
			int height, boolean keepAspectRatio) throws IOException {
		Thumbnails.of(source).size(width, height)
				.keepAspectRatio(keepAspectRatio).outputFormat("jpg")
				.toFile(output);
	}

	/**
	 * 旋转 ,正数：顺时针 负数：逆时针
	 *
	 * @param source
	 *            输入源
	 * @param output
	 *            输出源
	 * @param width
	 *            宽
	 * @param height
	 *            高
	 * @param rotate
	 *            角度
	 */
	public static void imgRotate(String source, String output, int width,
			int height, double rotate) throws IOException {
		Thumbnails.of(source).size(width, height).rotate(rotate)
				.outputFormat("jpg").toFile(output);
	}

	public static void imgRotate(File source, String output, int width,
			int height, double rotate) throws IOException {
		Thumbnails.of(source).size(width, height).rotate(rotate)
				.outputFormat("jpg").toFile(output);
	}

	/**
	 * 水印
	 *
	 * @param source
	 *            输入源
	 * @param output
	 *            输入源
	 * @param width
	 *            宽
	 * @param height
	 *            高
	 * @param position
	 *            水印位置 Positions.BOTTOM_RIGHT o.5f
	 * @param watermark
	 *            水印图片地址
	 * @param transparency
	 *            透明度 0.5f
	 * @param quality
	 *            图片质量 0.8f
	 */
	public static void imgWatermark(String source, String output, int width,
			int height, Position position, String watermark,
			float transparency, float quality) throws IOException {
		Thumbnails
				.of(source)
				.size(width, height)
				.watermark(position, ImageIO.read(new File(watermark)),
						transparency).outputQuality(0.8f).outputFormat("jpg")
				.toFile(output);
	}

	public static void imgWatermark(File source, String output, int width,
			int height, Position position, String watermark,
			float transparency, float quality) throws IOException {
		Thumbnails
				.of(source)
				.size(width, height)
				.watermark(position, ImageIO.read(new File(watermark)),
						transparency).outputQuality(0.8f).outputFormat("jpg")
				.toFile(output);
	}

	/**
	 * 裁剪图片
	 *
	 * @param source
	 *            输入源
	 * @param output
	 *            输出源
	 * @param position
	 *            裁剪位置
	 * @param x
	 *            裁剪区域x
	 * @param y
	 *            裁剪区域y
	 * @param width
	 *            宽
	 * @param height
	 *            高
	 * @param keepAspectRatio
	 *            默认是按照比例缩放的,值为false 时不按比例缩放
	 */
	public static void imgSourceRegion(String source, String output,
			Position position, int x, int y, int width, int height,
			boolean keepAspectRatio) throws IOException {
		Thumbnails.of(source).sourceRegion(position, x, y).size(width, height)
				.keepAspectRatio(keepAspectRatio).outputFormat("jpg")
				.toFile(output);
	}

	public static void imgSourceRegion(File source, String output,
			Position position, int x, int y, int width, int height,
			boolean keepAspectRatio) throws IOException {
		Thumbnails.of(source).sourceRegion(position, x, y).size(width, height)
				.keepAspectRatio(keepAspectRatio).outputFormat("jpg")
				.toFile(output);
	}

	/**
	 * 按坐标裁剪
	 *
	 * @param source
	 *            输入源
	 * @param output
	 *            输出源
	 * @param x
	 *            起始x坐标
	 * @param y
	 *            起始y坐标
	 * @param x1
	 *            结束x坐标
	 * @param y1
	 *            结束y坐标
	 * @param width
	 *            宽
	 * @param height
	 *            高
	 * @param keepAspectRatio
	 *            默认是按照比例缩放的,值为false 时不按比例缩放
	 */
	public static void imgSourceRegion(String source, String output, int x,
			int y, int x1, int y1, int width, int height,
			boolean keepAspectRatio) throws IOException {
		Thumbnails.of(source).sourceRegion(x, y, x1, y1).size(width, height)
				.keepAspectRatio(keepAspectRatio).toFile(output);
	}

	public static void imgSourceRegion(File source, String output, int x,
			int y, int x1, int y1, int width, int height,
			boolean keepAspectRatio) throws IOException {
		Thumbnails.of(source).sourceRegion(x, y, x1, y1).size(width, height)
				.keepAspectRatio(keepAspectRatio).outputFormat("jpg")
				.toFile(output);
	}

	/**
	 * 转化图像格式
	 *
	 * @param source
	 *            输入源
	 * @param output
	 *            输出源
	 * @param width
	 *            宽
	 * @param height
	 *            高
	 * @param format
	 *            图片类型，gif、png、jpg
	 */
	public static void imgFormat(String source, String output, int width,
			int height, String format) throws IOException {
		Thumbnails.of(source).size(width, height).outputFormat(format)
				.toFile(output);
	}

	public static void imgFormat(File source, String output, int width,
			int height, String format) throws IOException {
		Thumbnails.of(source).size(width, height).outputFormat(format)
				.outputFormat("jpg").toFile(output);
	}

	/**
	 * 输出到OutputStream
	 *
	 * @param source
	 *            输入源
	 * @param output
	 *            输出源
	 * @param width
	 *            宽
	 * @param height
	 *            高
	 * @return toOutputStream(流对象)
	 */
	public static OutputStream imgOutputStream(String source, String output,
			int width, int height) throws IOException {
		OutputStream os = new FileOutputStream(output);
		Thumbnails.of(source).size(width, height).outputFormat("jpg")
				.toOutputStream(os);
		return os;
	}

	public static OutputStream imgOutputStream(File source, String output,
			int width, int height) throws IOException {
		OutputStream os = new FileOutputStream(output);
		Thumbnails.of(source).size(width, height).outputFormat("jpg")
				.toOutputStream(os);
		return os;
	}

	/**
	 * 输出到BufferedImage
	 *
	 * @param source
	 *            输入源
	 * @param output
	 *            输出源
	 * @param width
	 *            宽
	 * @param height
	 *            高
	 * @param format
	 *            图片类型，gif、png、jpg
	 * @return BufferedImage
	 */
	public static BufferedImage imgBufferedImage(String source, String output,
			int width, int height, String format) throws IOException {
		BufferedImage buf = Thumbnails.of(source).size(width, height)
				.outputFormat("jpg").asBufferedImage();
		ImageIO.write(buf, format, new File(output));
		return buf;
	}

	public static BufferedImage imgBufferedImage(File source, String output,
			int width, int height, String format) throws IOException {
		BufferedImage buf = Thumbnails.of(source).size(width, height)
				.outputFormat("jpg").asBufferedImage();
		ImageIO.write(buf, format, new File(output));
		return buf;
	}
}

完