在kotlin中你可以用

file1.copyTo(file2)

file1是原始文件的对象，而file2是要复制到的新文件的对象

要复制文件并将其保存到目标路径，您可以使用下面的方法。

public static void copy(File src, File dst) throws IOException {
    InputStream in = new FileInputStream(src);
    try {
        OutputStream out = new FileOutputStream(dst);
        try {
            // Transfer bytes from in to out
            byte[] buf = new byte[1024];
            int len;
            while ((len = in.read(buf)) > 0) {
                out.write(buf, 0, len);
            }
        } finally {
            out.close();
        }
    } finally {
        in.close();
    }
}

在API 19+上，您可以使用Java自动资源管理:

public static void copy(File src, File dst) throws IOException {
    try (InputStream in = new FileInputStream(src)) {
        try (OutputStream out = new FileOutputStream(dst)) {
            // Transfer bytes from in to out
            byte[] buf = new byte[1024];
            int len;
            while ((len = in.read(buf)) > 0) {
                out.write(buf, 0, len);
            }
        }
    }
}

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();
}

现在使用Kotlin要简单得多:

 File("originalFileDir", "originalFile.name")
            .copyTo(File("newFileDir", "newFile.name"), true)

Trueorfalse用于覆盖目标文件

https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.io/java.io.-file/copy-to.html

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);
        }
    }