code: public static void copy(InputStream in, OutputStream out) throws IOException {
  
      byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];
  
      for (int length = in.read(buffer); length > 0; length = in.read(buffer)) {
        out.write(buffer, 0, length);
        out.flush();
      }
    }
docs: Copies the contents of the source {@link InputStream} to the target {@link OutputStream}.
  
  @param in the source {@link InputStream} to copy bytes from.
  @param out the target {@link OutputStream} to copy bytes to.
  @throws IOException if the copy operation results in an I/O error.
  @see java.io.InputStream
  @see java.io.OutputStream