java - 通过java上传mp4文件无法播放/已损坏

Question

我正在制作一个java程序，它能够使用他们的api将(主要是mp4)文件上传到主机openload.co，你可以找到here .

我的程序可以上传 mp4 视频，但无法播放。当我下载以前上传的视频并通过文件的属性检查其详细信息时，缺少视频和音频信息，因此服务器似乎不知道如何处理文件字节，尽管它识别了内容 -类型、大小和文件名。

我检查了谷歌和这个论坛，但还没有找到任何答案。

这是负责上传过程的代码。我希望有人知道缺少什么。

private static String uploadFile(URL uploadURL, Path file, String fileName, String fileNameWithType ) throws IOException{
    /*the size of the file, which is to be uploaded */
    long s = Files.size(file);
    /*the amount of additional bytes sent with the file */
    long offset = 220;
    /*the sum of the filesize and additional bytes */
    long actualBodySize = offset + s;

    // returned server response
    String response = null;
    //HTTP line-break
    String crlf = "\r\n";
    //mainly needed for end of multipart/form-data request
    String twoHyphens = "--";
    //the fields are separated by this boundary, a random number
    String boundary =  "---------------------"+Long.toString(System.currentTimeMillis());

//--------------------------------------------------------------------------------------------------------    
    HttpsURLConnection OutputConnection = (HttpsURLConnection) uploadURL.openConnection();
    OutputConnection.setDoOutput(true);
//--------------------------------------------------------------------------------------------------------        
    OutputConnection.setRequestProperty("Content-Type","multipart/form-data;boundary=" + boundary);
    //allows java to start sending data via network immediatly
    OutputConnection.setFixedLengthStreamingMode(actualBodySize);
    OutputConnection.setRequestProperty("Connection", "Keep-Alive");
    OutputConnection.setRequestProperty("Cache-Control", "no-cache");
//--------------------------------------------------------------------------------------------------------                                                                                         
//setting up the I/O-Streams

//OutputConnection.connect(); //not needed, getOutputStream does connect() on its own
    try(InputStream fileInput = newInputStream(file, READ);
        BufferedInputStream bfileInput = new BufferedInputStream(fileInput);
        OutputStream fileOutput = OutputConnection.getOutputStream();
        BufferedOutputStream bfileOutput = new BufferedOutputStream(fileOutput);
        DataOutputStream dfileOutput = new DataOutputStream(bfileOutput)){
//---------------------------------------------------------------------------------------------------------
//      manually writing the multipart/form-data request
        dfileOutput.writeBytes(twoHyphens + boundary + crlf);
        dfileOutput.writeBytes("Content-Disposition: form-data; name=\"" +
        fileName + "\"; filename=\"" + 
        fileNameWithType + "\"" + crlf);
        dfileOutput.writeBytes(crlf);
        dfileOutput.writeBytes("Content-Type: video/mp4"+crlf);
 //     dfileOutput.writeBytes("Content-Transfer-Encoding: binary" + crlf + crlf);
//--------------------------------------------------------------------------------------------------------------- 
//      uploading the file
        for(int byteCode = bfileInput.read(); byteCode >= 0; byteCode = bfileInput.read()){
            dfileOutput.write(byteCode);
        }
//---------------------------------------------------------------------------------------------------------------             
//      manually writing the end-part of the multipart/form-data request
        dfileOutput.writeBytes(crlf);
        dfileOutput.writeBytes(twoHyphens + boundary + twoHyphens + crlf);
        dfileOutput.flush();
//----------------------------------------------------------------------------------------------------------------
//      setting up inputstream in order to get the server response
        ...
//      extracting the download-url of the json-server-response
        ...

    }   
    OutputConnection.disconnect();
    return response;
}

Answer 1

我发现出了什么问题。我比较了测试视频本身和上传视频的实际大小。上传的大小比原始大小大 25 字节。事实证明，无论出于何种原因，这一行都被添加到了视频文件字节中:

dfileOutput.writeBytes("Content-Type: video/mp4"+crlf);

现在我已经删除了它，一切正常。