IOCipher copying using file channels

gistfile1.java

...

FileOutputStream os = null;
java.io.FileInputStream is = null;

try {
    os = new FileOutputStream("/test_file"); 
    is = new java.io.FileInputStream(this.getContentResolver().openInputStream(uri));

    FileChannel sourceFileChannel = is.getChannel();
    IOCipherFileChannel destinationFileChannel = os.getChannel();

    sourceFileChannel.transferTo(0, sourceFileChannel.size(), destinationFileChannel);
    sourceFileChannel.close();
    destinationFileChannel.close();
    
    ...