I'm using the AWS SDK for Android to download objects from S3 to my Android tablet. In an attempt to route traffic through a proxy (right now I'm using Charles Proxy on my local network as a test bed) to throttle the download speed of the S3 downloads, I'm using ClientConfiguration.setProxyHost and setProxyPort but the S3 TransferUtility appears to be ignoring the setting and going directly to AWS S3 not the proxy.

The code without the proxy set works fine. Objects are downloaded successfully. The code with the proxy set behaves exactly the same, and the proxy doesn't show any connection from the tablet.

I have proven to myself that the proxy works by setting the proxy host and port in the Android tablet Wifi settings (setting proxy manually) and the proxy shows the AWS S3 connections traveling through the proxy successfully.

At first, I thought the AmazonS3Client was ignoring my ClientConfiguration entirely but I've proven that when I set the ClientConfiguration.setProtocol from HTTPS to HTTP the AWS TransferUtility changes from http to https as the AWS endpoint.

The code looks like every other sample code for setting the proxy that I can find using ClientConfiguration and TransferUtility.

ClientConfiguration getClientConfiguration() {
    return new ClientConfiguration()
            .withMaxConnections(2)
            .withProxyHost("192.168.1.137")
            .withProxyPort(8888)
            .withConnectionTimeout(30 * 1000) // Wait 30 seconds to make a connection
            .withSocketTimeout(0); // Keep open connections open indefinitely (we have very large downloads)
}
public S3Controller(Context context) {
    java.util.logging.Logger.getLogger("com.amazonaws").setLevel(java.util.logging.Level.FINEST);
    applicationContext = context.getApplicationContext();

    clientConfig = getClientConfiguration();

    s3Client = new AmazonS3Client(getCredentials(), clientConfig);

    transferUtility = new TransferUtility(s3Client, applicationContext);

    pendingTransfers = new PendingTransferQueue();

}

// ... later

TransferObserver observer = transferUtility.download(BuildConfig.S3_BUCKET, key, file);

As you can see I also tried setting the logging level of the amazonaws to FINEST in order to get some visibility on where the proxy is failing with no additional logging showing up.

Any suggestion on why AWS SDK is ignoring my proxy or how I can set logging to find out more details on where it is failing?

Thanks in advance.