public static long copy(InputStream inputStream, OutputStream outputStream) throws IOException {
		return copy( inputStream, outputStream, DEFAULT_CHUNK_SIZE );
	}
public static long copy(InputStream inputStream, OutputStream outputStream) throws IOException {
		return copy( inputStream, outputStream, DEFAULT_CHUNK_SIZE );
	}
public static long copy ( InputStream inputStream , OutputStream outputStream ) throws IOException { return copy ( inputStream , outputStream , DEFAULT_CHUNK_SIZE ) ; }
input->output字节流copy
@param inputStream
@param outputStream
@return
@throws IOException
input - > output字节流copy