Java thumbnails工具类的使用

Thumbnails.of(fromPic).sourceRegion(Positions.CENTER, 300, 300).scale(1.0).toFile(toPic);

 

添加依赖

<dependency>
    <groupId>net.coobird</groupId>
    <artifactId>thumbnailator</artifactId>
    <version>0.4.8</version>
</dependency>

单个图片等比例缩放

File file = new File("c:\\test.png");
Thumbnails.of(new FileInputStream(file)).scale(3.0).toFile(new File("c:\\yyyyy.png"));

3.0是一个double类型的数字，缩放比例，大于1就是变大，小于1就是缩小.

批量产生缩略图

Thumbnails.of(new File("D:\\pics").listFiles()).scale(0.2).outputFormat("png")
                .toFiles(Rename.PREFIX_DOT_THUMBNAIL);

控制图片质量，图片尺寸不变

Thumbnails.of(fromPic).scale(1f).outputQuality(0.25f).toFile(toPic); 

outputQuality就是用来控制图片质量的

给图片加水印

    Thumbnails.of(fromPic).scale(0.8)
                    .watermark(Positions.BOTTOM_RIGHT, ImageIO.read(waterPic), 0.5f)
                    .outputQuality(0.8f).toFile(toPic);

Positions.BOTTOM_RIGHT指的是水印位置,ImageIO.read(waterPic)指的是水印位置,0.5f是透明度

旋转图片

Thumbnails.of(fromPic).scale(0.5).rotate(90).toFile(toPic);  

图片裁剪

Thumbnails.of(fromPic).sourceRegion(Positions.CENTER, 300, 300).scale(1.0).toFile(toPic);