Use filechannel to copy files

The file channel defines two methods for direct file transfer:
Int transferto (INT position, Long Count, writablebytechannel DST );
This function transfers count bytes to the DST channel from position.
Int transferfrom (readablebytechannel SRC, long position, Long Count );
Transfers count bytes from the SRC channel to the file. position is the position where the file is written.
The channel obtained from fileinputstream only supports transferto, while the channel obtained from fileoutputstream only supports the tansferfrom () method.

1. Filechannel SFC =NewFileinputstream ("D: // suqiang // from.txt"). getchannel ();
2. Filechannel TFC =NewFileoutputstream ("D: // suqiang // to.txt"). getchannel ();
3. SFC. transferto (0, SFC. Size (), TFC );
4. SFC. Close ();
5. TFC. Close ();