如何从assets文件夹安装APK文件？

try {
    // 获取assets文件夹中的APK文件输入流
    InputStream inputStream = getAssets().open("example.apk");

    // 将APK文件保存到设备存储中
    File apkFile = new File(getExternalFilesDir(null), "example.apk");
    FileOutputStream outputStream = new FileOutputStream(apkFile);
    byte[] buffer = new byte[1024];
    int length;
    while ((length = inputStream.read(buffer)) != -1) {
        outputStream.write(buffer, 0, length);
    }
    outputStream.close();
    inputStream.close();

    // 安装APK文件
    Intent intent = new Intent(Intent.ACTION_VIEW);
    intent.setDataAndType(Uri.fromFile(apkFile), "application/vnd.android.package-archive");
    intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    startActivity(intent);
} catch (IOException e) {
    e.printStackTrace();
}