利用FileChannel复制文件

方法1：  
 public static void copyFile(File src, File dst) throws IOException {
        FileChannel inChannel = new FileInputStream(src).getChannel();
        FileChannel outChannel = new FileOutputStream(dst).getChannel();

        try {
            //从inChannel文件中读出count bytes ，并写入outChannel文件。
            inChannel.transferTo(0, inChannel.size(), outChannel);
        } finally {

        if (inChannel != null)
            inChannel.close();
        if (outChannel != null)
            outChannel.close();
        }
    }
也可以这么写：
 public static void copyFile(File src, File dst) throws IOException {
        private static final int BSIZE = 1024;        
        FileChannel inChannel = new FileInputStream(src).getChannel();
        FileChannel outChannel = new FileOutputStream(dst).getChannel();

        try {
            //从inChannel文件中读出count bytes ，并写入outChannel文件。
            ByteBuffer bb = ByteBuffer.allocate(BSIZE);
            while(in.read(bb)!=-1){
                  bb.flip();
                  out.write(bb);
                  bb.clear();//prepare for reading;清空缓冲区；
            }
           
        } finally {

        if (inChannel != null)
            inChannel.close();
        if (outChannel != null)
            outChannel.close();
        }
    }
方法2：
try {
    BufferedInputStream bis = new BufferedInputStream(new FileInputStream("c:\\updatedatfix.log"));
    BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream("c:\\tt.log"));
    byte[] buff = new byte[1024];
    int len =0;
    while((len=bis.read(buff,0,1024))!=-1){
     bos.write(buff, 0, len);
    }
    bis.close();
    bos.close();
   } catch (Exception e) {
    e.printStackTrace();
   }
方法3：
try {
    FileReader fr = new FileReader("c:\\updatedatfix.log");
    BufferedReader br = new BufferedReader(fr);
    FileWriter fw = new FileWriter("c:\\temp2.txt");
    PrintWriter pw = new PrintWriter(fw, true);
    String line;
    while ((line = br.readLine()) != null) {
     pw.println(line);
    }
   } catch (Exception e) {
    e.printStackTrace();
   }