Thumbnailator 是一个用来生成图像缩略图、裁切、旋转、添加水印等操作的 Java 类库，通过很简单的代码即可生成图片缩略图，也可直接对一整个目录的图片生成缩略图。

Thumbnailator对图片的简单操作代码如下：

import java.awt.image.BufferedImage;

import java.io.File;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.OutputStream;

import javax.imageio.ImageIO;

import net.coobird.thumbnailator.Thumbnails;

import net.coobird.thumbnailator.geometry.Positions;

/**

*

* @author yaohucaizi

*

*/

public class ThumbnailatorTest {

/**

*

* @param args

* @throws IOException

*/

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

ThumbnailatorTest thumbnailatorTest = new ThumbnailatorTest();

thumbnailatorTest.test1();

thumbnailatorTest.test2();

thumbnailatorTest.test3();

thumbnailatorTest.test4();

thumbnailatorTest.test5();

thumbnailatorTest.test6();

thumbnailatorTest.test7();

thumbnailatorTest.test8();

thumbnailatorTest.test9();

}

/**

* 指定大小进行缩放

*

* @throws IOException

*/

private void test1() throws IOException {

/*

* size(width,height) 若图片横比200小，高比300小，不变

* 若图片横比200小，高比300大，高缩小到300，图片比例不变 若图片横比200大，高比300小，横缩小到200，图片比例不变

* 若图片横比200大，高比300大，图片按比例缩小，横为200或高为300

*/

Thumbnails.of("images/test.jpg").size(200, 300).toFile(

"C:/image_200x300.jpg");

Thumbnails.of("images/test.jpg").size(2560, 2048).toFile(

"C:/image_2560x2048.jpg");

}

/**

* 按照比例进行缩放

*

* @throws IOException

*/

private void test2() throws IOException {

/**

* scale(比例)

*/

Thumbnails.of("images/test.jpg").scale(0.25f)

.toFile("C:/image_25%.jpg");

Thumbnails.of("images/test.jpg").scale(1.10f).toFile(

"C:/image_110%.jpg");

}

/**

* 不按照比例，指定大小进行缩放

*

* @throws IOException

*/

private void test3() throws IOException {

/**

* keepAspectRatio(false) 默认是按照比例缩放的

*/

Thumbnails.of("images/test.jpg").size(120, 120).keepAspectRatio(false)

.toFile("C:/image_120x120.jpg");

}

/**

* 旋转

*

* @throws IOException

*/

private void test4() throws IOException {

/**

* rotate(角度),正数：顺时针 负数：逆时针

*/

Thumbnails.of("images/test.jpg").size(1280, 1024).rotate(90).toFile(

"C:/image+90.jpg");

Thumbnails.of("images/test.jpg").size(1280, 1024).rotate(-90).toFile(

"C:/iamge-90.jpg");

}

/**

* 水印

*

* @throws IOException

*/

private void test5() throws IOException {

/**

* watermark(位置，水印图，透明度)

*/

Thumbnails.of("images/test.jpg").size(1280, 1024).watermark(

Positions.BOTTOM_RIGHT,

ImageIO.read(new File("images/watermark.png")), 0.5f)

.outputQuality(0.8f).toFile(

"C:/image_watermark_bottom_right.jpg");

Thumbnails.of("images/test.jpg").size(1280, 1024).watermark(

Positions.CENTER,

ImageIO.read(new File("images/watermark.png")), 0.5f)

.outputQuality(0.8f).toFile("C:/image_watermark_center.jpg");

}

/**

* 裁剪

*

* @throws IOException

*/

private void test6() throws IOException {

/**

* 图片中心400*400的区域

*/

Thumbnails.of("images/test.jpg").sourceRegion(Positions.CENTER, 400,

400).size(200, 200).keepAspectRatio(false).toFile(

"C:/image_region_center.jpg");

/**

* 图片右下400*400的区域

*/

Thumbnails.of("images/test.jpg").sourceRegion(Positions.BOTTOM_RIGHT,

400, 400).size(200, 200).keepAspectRatio(false).toFile(

"C:/image_region_bootom_right.jpg");

/**

* 指定坐标

*/

Thumbnails.of("images/test.jpg").sourceRegion(600, 500, 400, 400).size(

200, 200).keepAspectRatio(false).toFile(

"C:/image_region_coord.jpg");

}

/**

* 转化图像格式

*

* @throws IOException

*/

private void test7() throws IOException {

/**

* outputFormat(图像格式)

*/

Thumbnails.of("images/test.jpg").size(1280, 1024).outputFormat("png")

.toFile("C:/image_1280x1024.png");

Thumbnails.of("images/test.jpg").size(1280, 1024).outputFormat("gif")

.toFile("C:/image_1280x1024.gif");

}

/**

* 输出到OutputStream

*

* @throws IOException

*/

private void test8() throws IOException {

/**

* toOutputStream(流对象)

*/

OutputStream os = new FileOutputStream(

"C:/image_1280x1024_OutputStream.png");

Thumbnails.of("images/test.jpg").size(1280, 1024).toOutputStream(os);

}

/**

* 输出到BufferedImage

*

* @throws IOException

*/

private void test9() throws IOException {

/**

* asBufferedImage() 返回BufferedImage

*/

BufferedImage thumbnail = Thumbnails.of("images/test.jpg").size(1280,

1024).asBufferedImage();

ImageIO.write(thumbnail, "jpg", new File(

"C:/image_1280x1024_BufferedImage.jpg"));

}

}

转载：http://www.cnblogs.com/dyllove98/archive/2013/08/02/3233984.html