public static Integer getS3StreamBufferSize() {
        String s =
            System.getProperty(SDKGlobalConfiguration.DEFAULT_S3_STREAM_BUFFER_SIZE);
        if (s == null)
            return null;
        try {
            return Integer.valueOf(s);
        } catch (Exception e) {
            log.warn("Unable to parse buffer size override from value: " + s);
        }
        return null;
    }
Returns the value of the system property
{@link SDKGlobalConfiguration#DEFAULT_S3_STREAM_BUFFER_SIZE} as an
Integer; or null if not set. This method exists for backward
compatibility reasons.
aws-java-sdk-s3/src/main/java/com/amazonaws/services/s3/internal/Constants.java