Java编程思想这本书很好

				//: c12:TransferTo.java
				// Using transferTo() between channels
				// {Args: TransferTo.java TransferTo.txt}
				// {Clean: TransferTo.txt} 
				// From 'Thinking in Java, 3rd ed.' (c) Bruce Eckel 2002
				// www.BruceEckel.com. See copyright notice in CopyRight.txt.
				import java.io.*;
				import java.nio.*;
				import java.nio.channels.*;
				
				public class TransferTo {
				  public static void main(String[] args) throws Exception {
				    if(args.length != 2) {
				      System.out.println("arguments: sourcefile destfile");
				      System.exit(1);
				    }
				    FileChannel 
				      in = new FileInputStream(args[0]).getChannel(),
				      out = new FileOutputStream(args[1]).getChannel();
				    in.transferTo(0, in.size(), out);
				    // Or:
				    // out.transferFrom(in, 0, in.size());
				  }
				} ///:~