Thumbnailator 图片压缩 至指定大小

String dir = "c:\\09";
        File[] files = new File(dir).listFiles();
        for (File file : files) {
            try {
                long length = file.length();
                System.out.println("start --->" + file);
                while (length > 1024 * 300) {
                    length = file.length();
                    Thumbnails.of(file)
                            // 图片缩放率，不能和size()一起使用
                            .scale(0.8)
                            //.size(desWidth, desHeight)
                            //.outputQuality(0.8)
                            // 缩略图保存目录,该目录需存在，否则报错
                            .toFiles(new File("c:\\09"), Rename.NO_CHANGE);
                    System.out.println("compressed：" + length);
                }
            } catch (Exception err) {
                System.out.println(err.fillInStackTrace() + " ---> " + file.getAbsolutePath());
            }
        }

https://blog.csdn.net/wangpeng047/article/details/19624993

https://www.cnblogs.com/ryan304/p/9546670.html

springboot页面上传图片过大的后台解决办法-------------通过Thumbnails做图片压缩,图片格式转换------这一篇就够！
https://blog.csdn.net/zhanglf02/article/details/102985887
https://blog.csdn.net/null111666/article/details/86063751

https://springboot.io/t/topic/2889

从零搭建自己的SpringBoot后台框架(二十二)

https://juejin.cn/post/6844903615925092366

https://blog.csdn.net/xhanguomzhu/article/details/108682880

https://www.cnblogs.com/zhizou/p/11244015.html
https://github.com/coobird/thumbnailator/wiki/Examples