channelcopy.java

来自「Java编程思想第三版,作者书中全部原代码,」· Java 代码 · 共 28 行

//: c12:ChannelCopy.java
// Copying a file using channels and buffers
// {Args: ChannelCopy.java test.txt}
// {Clean: test.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 ChannelCopy {
  private static final int BSIZE = 1024;
  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();
    ByteBuffer buffer = ByteBuffer.allocate(BSIZE);
    while(in.read(buffer) != -1) {
      buffer.flip(); // Prepare for writing
      out.write(buffer);
      buffer.clear();  // Prepare for reading
    }
  }
} ///:~