或者，您也可以使用FileChannel来复制文件。在复制大文件时，它可能比字节复制方法更快。如果你的文件大于2GB，你就不能使用它。

public void copy(File src, File dst) throws IOException {
    FileInputStream inStream = new FileInputStream(src);
    FileOutputStream outStream = new FileOutputStream(dst);
    FileChannel inChannel = inStream.getChannel();
    FileChannel outChannel = outStream.getChannel();
    inChannel.transferTo(0, inChannel.size(), outChannel);
    inStream.close();
    outStream.close();
}

现在回答可能太迟了，但最方便的方法是使用

FileUtils's

文件srcFile，文件destFile

这就是我所做的

`

private String copy(String original, int copyNumber){
    String copy_path = path + "_copy" + copyNumber;
        try {
            FileUtils.copyFile(new File(path), new File(copy_path));
            return copy_path;
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

`

这在Android O (API 26)上很简单，如你所见:

  @RequiresApi(api = Build.VERSION_CODES.O)
  public static void copy(File origin, File dest) throws IOException {
    Files.copy(origin.toPath(), dest.toPath());
  }

下面是一个解决方案，如果在复制时发生错误，它实际上会关闭输入/输出流。这个解决方案利用apache Commons IO IOUtils方法来复制和处理流的关闭。

    public void copyFile(File src, File dst)  {
        InputStream in = null;
        OutputStream out = null;
        try {
            in = new FileInputStream(src);
            out = new FileOutputStream(dst);
            IOUtils.copy(in, out);
        } catch (IOException ioe) {
            Log.e(LOGTAG, "IOException occurred.", ioe);
        } finally {
            IOUtils.closeQuietly(out);
            IOUtils.closeQuietly(in);
        }
    }

Kotlin扩展它

fun File.copyTo(file: File) {
    inputStream().use { input ->
        file.outputStream().use { output ->
            input.copyTo(output)
        }
    }
}

简单易行的方法!

import android.os.FileUtils;

try (InputStream in = new FileInputStream(sourceFile); 
     OutputStream out = new FileOutputStream(destinationFile) ){
                
     FileUtils.copy(in, out); 

}catch(Exception e){
     Log.d("ReactNative","Error copying file: "+e.getMessage());
}