Java NIO Channel to Channel Transfers（六）

原文链接：http://tutorials.jenkov.com/java-nio/channel-to-channel-transfers.html，如有侵权，立删

Java NIO Channel to Channel Transfers

• transferFrom（）
• transferTo（）

　　如果两个channel中有一个是filechannel，那么两个channel就可以互相传输数据。

　TransferFrom()

　　FileChannel.transferFrom()将一个channel中的数据传输到FileChannel中去。上例子

RandomAccessFile fromFile = new RandomAccessFile("fromFile.txt", "rw");
FileChannel      fromChannel = fromFile.getChannel();

RandomAccessFile toFile = new RandomAccessFile("toFile.txt", "rw");
FileChannel      toChannel = toFile.getChannel();

long position = 0;
long count    = fromChannel.size();

toChannel.transferFrom(fromChannel, position, count);

　　一些SocketChannel实现可能只会传输已经准备好的数据，即使还有正在准备的很多可用数据。因此SocketChannel可能不会传输全部的数据到FileChannel中。

　TransferTo()

　　FileChannel.transferTo()是FileChannel向其他的channel传输数据。

RandomAccessFile fromFile = new RandomAccessFile("fromFile.txt", "rw");
FileChannel      fromChannel = fromFile.getChannel();

RandomAccessFile toFile = new RandomAccessFile("toFile.txt", "rw");
FileChannel      toChannel = toFile.getChannel();

long position = 0;
long count    = fromChannel.size();

fromChannel.transferTo(position, count, toChannel);

　　这里SocketChannel，还是老毛病。