java实现后台上传压缩图片

控制器的方法
public ResultMap fileUpload(@RequestParam("file") MultipartFile file) {
    String pictureName = DateUtil.getAllTime();
    //获取压缩后的图片名称，随机生成
    String smallerPictureName = UUID.randomUUID().toString();
    try {
        //未压缩前的上传路径
        String fileSavePath = getFileUploadPath() + "/image/" + pictureName + ".jpg";
        File tempFile = new File(fileSavePath);
        file.transferTo(tempFile);
        //压缩后的路径
        String smallFileSavePath = getFileUploadPath()+"/image/"+smallerPictureName+".jpg";
        //获取文件大小 KB
        long size = file.getSize()/1024;
        //判断文件大小对图片质量进行压缩,尺寸不变，范围0.01~1.0,值越低压缩效率越高。图片低于600K不进行压缩
        if(size>=7380){
            Thumbnails.of(fileSavePath).scale(1f).outputQuality(0.01f).toFile(smallFileSavePath);
            tempFile.delete();
            return getResultMap(SUCCESS_CODE,smallerPictureName);
        }else if(size>=4096&&size<7380){
            Thumbnails.of(fileSavePath).scale(1f).outputQuality(0.2f).toFile(smallFileSavePath);
            tempFile.delete();
            return getResultMap(SUCCESS_CODE,smallerPictureName);
        }else if(size>=1024&&size<4096){
            Thumbnails.of(fileSavePath).scale(1f).outputQuality(0.3f).toFile(smallFileSavePath);
            tempFile.delete();
            return getResultMap(SUCCESS_CODE,smallerPictureName);
        }else if(size>=600&&size<1024){
            Thumbnails.of(fileSavePath).scale(1f).outputQuality(1f).toFile(smallFileSavePath);
            tempFile.delete();
            return getResultMap(SUCCESS_CODE,smallerPictureName);
        }else{
            return getResultMap(SUCCESS_CODE,pictureName);
        }
    } catch (Exception e) {
        return getResultMap(ERROR_CODE,"图片上传失败，请稍后重试，或联系管理员");
    }
}

HTML页面

layui.use(['form','layer','upload'], function(){
    var $ = layui.$, form = layui.form, upload = layui.upload, layer = layui.layer;

    // 上传缩略图
    upload.render({
        elem: '.thumbBox',
        data: {typePicture: $('#typePicture').val(), sortPicture: $('#sortPicture').val()},
        url: '/kaptcha/fileUpload',

        before: function(obj){
            //预读本地文件，如果是多文件，则会遍历。(不支持ie8/9)
            layer.load();
            obj.preview(function(index, file, result){
                $('.thumbImg').attr('src', result);
            });
        },
        done: function(res){
            // alert("图片上传成功吗，保存后生效");
            layer.closeAll('loading');
            $("#pictureId").val(res.data);
            $('.thumbBox').css("background","#fff");
            if(res.code != 0){
                alert(res.data);
            }
        }
    });



HTML页面是我目前所用的，可能会有许多不足，多多见谅！
我只是一个小白