Question

我有一个奇怪的问题，我真的会有所了解。我有一些代码下载各种文件。有些文件返回“transfer-encoding”标题，其值为“chunked”，我很确定这是导致我出现问题的原因。

这里真的很奇怪。当我在3g上运行我的Motorolla Droid时，具有此编码的文件无法正确下载，因为它在读取所有字节之前完成下载，因此我有一个损坏的文件。但是，在完全相同的手机上使用WiFi，同样的文件下载就好了。

这听起来像是服务器问题吗？ android问题？ 3g问题？我的代码问题？

以下是我用来阅读响应标题的一些代码：

private void readResponseHeaders(HttpResponse response) throws StopRequest {
        Header header = response.getFirstHeader("Content-Disposition");
        if (header != null) {
            mInfo.mInnerState.mHeaderContentDisposition = header.getValue();
        }
        header = response.getFirstHeader("Content-Location");
        if (header != null) {
            mInfo.mInnerState.mHeaderContentLocation = header.getValue();
        }
        if (mInfo.mMimeType == null) {
            header = response.getFirstHeader("Content-Type");
            if (header != null) {
                mInfo.mMimeType = sanitizeMimeType(header.getValue());
            }
        }
        header = response.getFirstHeader("ETag");
        if (header != null) {
            mInfo.mInnerState.mHeaderETag = header.getValue();
        }
        String headerTransferEncoding = null;
        header = response.getFirstHeader("Transfer-Encoding");
        if (header != null) {
            headerTransferEncoding = header.getValue();
        }
        if (headerTransferEncoding == null) {
            header = response.getFirstHeader("Content-Length");
            if (header != null) {
                mInfo.mInnerState.mHeaderContentLength = header.getValue();
                mInfo.mTotalBytes = Long.parseLong(mInfo.mInnerState.mHeaderContentLength);

                if (!mFileManager.hasSufficientSpace(mInfo.mTotalBytes, mBasePath)){
                    throw new StopRequest(ServiceDownloadConstants.STATUS_INSUFFICIENT_SPACE_ERROR, "Not Enough Space");
                }
            }
        } else {
            // Ignore content-length with transfer-encoding - 2616 4.4 3
            if (ServiceDownloadConstants.LOGVV) {
                Log.v(ServiceDownloadConstants.TAG,
                        "ignoring content-length because of xfer-encoding");
            }
        }
        if (ServiceDownloadConstants.LOGVV) {
            Log.v(ServiceDownloadConstants.TAG, "Content-Disposition: " + mInfo.mInnerState.mHeaderContentDisposition);
            Log.v(ServiceDownloadConstants.TAG, "Content-Length: " + mInfo.mInnerState.mHeaderContentLength);
            Log.v(ServiceDownloadConstants.TAG, "Content-Location: " + mInfo.mInnerState.mHeaderContentLocation);
            Log.v(ServiceDownloadConstants.TAG, "Content-Type: " + mInfo.mMimeType);
            Log.v(ServiceDownloadConstants.TAG, "ETag: " + mInfo.mInnerState.mHeaderETag);
            Log.v(ServiceDownloadConstants.TAG, "Transfer-Encoding: " + headerTransferEncoding);
        }

        boolean noSizeInfo = mInfo.mInnerState.mHeaderContentLength == null
                && (headerTransferEncoding == null
                    || !headerTransferEncoding.equalsIgnoreCase("chunked"));
        if (!mInfo.mNoIntegrity && noSizeInfo) {
            throw new StopRequest(ServiceDownloadConstants.STATUS_HTTP_DATA_ERROR,
            "can't know size of download, giving up");
        }
    }

以下是我用来传输数据的一些代码：

private void transferData(byte[] data, InputStream entityStream) throws StopRequest {
        for (;;) {
            int bytesRead = readFromResponse( data, entityStream);
            if (bytesRead == -1) {
                // success, end of stream already reached
                handleEndOfStream();
                return;
            }

            writeDataToDestination(data, bytesRead);
            mInfo.mInnerState.mBytesSoFar += bytesRead;

            /** Update SHA1 if needed **/
            if( mInfo.mEnclosure.getHash() != null && mSha1 != null ){
                mSha1.update( data, 0, bytesRead );
            }

            if (ServiceDownloadConstants.LOGVV) {
                Log.v(ServiceDownloadConstants.TAG, "downloaded " + mInfo.mInnerState.mBytesSoFar + " for "
                     + mInfo.mEnclosure.getUrl());
            }

            checkPausedOrCanceled();
        }
    }

修改经过进一步的调试，即使没有发送“transfer-encoding”标题，我也收到了完全相同的结果，所以看起来我的问题就像在Wifi上工作一样通用而且它不在3g上。< / p>

Answer 1

3G提供商缓存文件，缓存有时会被破坏。尝试在您的请求上设置no-cache标头。

在android上下载带有transfer-encoding标头的文件

1 个答案: