oss20190517 upload part api set header 'Content-Type' invalid

the upload part api can't identify the file mime ,so need set the Content-Type in the api InitiateMultipartUpload，there are not ContentType method, so I used headerParam，but after uploaded ,the Content-Type not change, what the right way to change the Content-Type?

 InitiateMultipartUploadRequest initiateMultipartUploadRequest = InitiateMultipartUploadRequest.builder()
                    .bucket(bucket)
                    .key(ossKey)
                    .headerParam("Content-Type", FileTypeUtils.getContentType(file))//here
                    .build();

Start with the InitiateMultipartUploadRequest builder and the multipart upload flow shown in the issue, then compare headerParam("Content-Type") with the Alibaba Cloud API documentation linked there. Confirm the correct request field or step by verifying that the uploaded object retains the intended MIME type.