Java基础之IO流，文件的复制原理与示例

import java.io.*;

class FileCopyDemo
{
    /*
     * 文件的复制
     */
    public static void main(String[] args)
    {
        FileWriter fw = null;
        FileReader fr = null;
        
        try
        {
            fr = new FileReader("d:\\works\\demo.txt");
            fw = new FileWriter("d:\\demo.txt");
            
            char[] buffer = new char[1024];
            int length = 0;
            
            while((length=fr.read(buffer))!=-1)
            {
                fw.write(buffer,0,length);
            }
        }
        catch(IOException e)
        {
            sop(e.getMessage());
        }
        finally
        {
            try            
            {
                if(null!=fw) fw.close();
                if(null!=fr) fr.close();
            }
            catch(IOException e)
            {
                sop(e.getMessage());
            }
        }
    }
    
    public static void sop(Object obj)
    {
        System.out.println(obj);
    }
}