SpringMvc 使用Thumbnails压缩图片

```java

 @PostMapping(value = "/upLoadFile")
@ApiOperation(value = "上传文件")
public Result upLoadFile(@RequestParam("file") MultipartFile file) {
    try {
      log.info("上传文件大小：" + file.getSize() / 1024 + "kb;文件名称:" + file.getOriginalFilename());
     ByteArrayOutputStream byteArrayOutputStreamut = new ByteArrayOutputStream();
     Thumbnails.of(file.getInputStream())
              .scale(0.08f)//放大还是缩小
              .outputQuality(0.5f)//图片质量
              .toOutputStream(byteArrayOutputStreamut);
       log.info("压缩后文件大小：" + byteArrayOutputStreamut.toByteArray().length / 1024 + "kb;");
       //下面是上传到阿里云。。。可以忽略
        return Result.success(uploadFile.uploadAndReturnUrl(file.getInputStream(), file.getOriginalFilename()));
    } catch (IOException e) {
        e.printStackTrace();
    }
    return Result.fail("上传文件失败");
}