Thumbnailator 图片压缩

        <dependency>
            <groupId>net.coobird</groupId>
            <artifactId>thumbnailator</artifactId>
            <version>0.4.7</version>
        </dependency>

    @ApiOperation(value = "简单上传:上传图片 并压缩", notes = " " +
            "<br/>bucketName leysen1855 " +
            "<br/>objectName xc/20210105test2.jpg")
    @RequestMapping(value = "putObjectImageCompress", method = RequestMethod.POST)
    @ResponseBody
    public CommonResult<PutObjectResult> putObjectImageCompress(@RequestParam("bucketName") String bucketName
            , @RequestParam("objectName") String objectName, @RequestParam("file") MultipartFile multipartFile) throws Exception {

        if (multipartFile.getSize() > 10 * 1024 * 1024) {
            throw new Exception("上传图片大小不能超过10M！");
        }
        InputStream inputStream = multipartFile.getInputStream();

        // 把图片读入到内存中
        BufferedImage bufImg = ImageIO.read(inputStream);
        int width = bufImg.getWidth();
        int height = bufImg.getHeight();
        log.info("{},height:{}", width, height);
        // 压缩代码
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        bufImg = Thumbnails.of(bufImg)
                // .scale(0.5f)     // 比例
                // .forceSize(400, 300)
                .size(400, 400)
                // .rotate(90)        // 转角90°(顺时针)
                .outputQuality(1f) // outputQuality：输出的图片质量
                .outputFormat("jpg") // outputFormat：输出的图片格式
                // 水印设置：在图片右下角，水印图片为watermark.png，透明度为50%
                // .watermark(Positions.BOTTOM_RIGHT, ImageIO.read(new File("watermark.png")), 0.5f)
                .asBufferedImage();
        //先转成jpg格式来压缩,然后在通过OSS来修改成源文件本来的后缀格式
        ImageIO.write(bufImg, "jpg", bos);
        //获取输出流
        inputStream = new ByteArrayInputStream(bos.toByteArray());

        PutObjectResult putObjectResult = ossClient.putObject(bucketName, objectName, inputStream);
        return CommonResult.success(putObjectResult);
    }

官方示例:https://github.com/coobird/thumbnailator/wiki/Examples