java 文件拷贝后文件损坏

 

今天用java写了一个关于文件拷贝的小工具FileUtil.java

我用了一个方法：copyFile(File source,File destnation)

我发现拷贝压缩文件，exe等文件后，文件大小一样，可是压缩文件无法打开，exe无法执行了

代码如下：

 public static boolean copyFile(File source, File destnation) {
  boolean rs = false;
  InputStream is = null;
  int count = 0;
  OutputStream os = null;
  byte buffer[] = new byte[BUFFER_SIZE];
  try {
   if (source != null && destnation != null) {
    if (source.isFile()) {
     if (destnation.isDirectory()) {
      File temp = new File(destnation.getAbsolutePath()
        + SEPRATOR + source.getName());
      is = new FileInputStream(source);
      os = new FileOutputStream(temp);
      while (-1 != (count = is.read())) {
       is.read(buffer, 0, buffer.length);
       os.write(buffer, 0, buffer.length);
      }
     } else {
      is = new FileInputStream(source);
      os = new FileOutputStream(destnation);
      while (-1 != (count = is.read())) {
       is.read(buffer, 0, buffer.length);
       os.write(buffer, 0, buffer.length);
      }
     }
    }
    rs = true;
   }
  } catch (FileNotFoundException e) {
   e.printStackTrace();
  } catch (IOException e) {
   e.printStackTrace();
  } finally {
   try {
    is.close();
    os.close();
   } catch (IOException e) {
    e.printStackTrace();
   }

  }
  return rs;
 }

各位有什么办法吗？我实在是找不原因