thumbnailator缩略图

<!-- https://mvnrepository.com/artifact/net.coobird/thumbnailator -->
<dependency>
<groupId>net.coobird</groupId>
<artifactId>thumbnailator</artifactId>
<version>0.4.8</version>
</dependency>

http://blog.csdn.net/yhhazr/article/details/7866491

	String fileExt = getExt(savePath);

// 生成缩略图
if (ThumbnailatorUtils.isSupportedOutputFormat(fileExt)) {
createThumb(physicalPath);
savePath += "_800.jpg";
}

private static String getExt(String path) {
int index = path.lastIndexOf('.');
return path.substring(index + 1).toLowerCase();
}

private static void createThumb(String path) throws IOException {
Thumbnails.of(path).outputFormat("jpg").size(800, 2000).toFile(path + "_800.jpg");
}

/*
* 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/a380_1280x1024.jpg")
.size(200, 300)
.toFile("c:/a380_200x300.jpg");

Thumbnails.of("images/a380_1280x1024.jpg")
.size(2560, 2048)
.toFile("c:/a380_2560x2048.jpg");