获取assert目录下文件名及读取

从assert文件下获取文件名字

String[] fl1 = getAssets().list("第一层");
得到数据  ["images", "hello.txt"]

String[] fl1 = getAssets().list("第一层/第二层");
得到数据  [ "helloworld.txt"]

将assert文件copy到sd卡

/**
 *
 * @param fileName   "第一层/第二层/helloworld.txt"
 * @param desDir  "/mnt/sdcard/mypath/"
 * @throws Exception
 */
private void CopyAssetFile(String fileName, String desDir) throws Exception {
    String strCpSdPath = desDir + fileName;//  "/mnt/sdcard/mypath/第一层/第二层/helloworld.txt"
    File file = new File(strCpSdPath);
    

if (!file.getParentFile().exists()) {
if (!file.getParentFile().mkdirs()) {
            Log.i("--CopyAssets--", "cannot create directory.");
            throw new Exception("存储卡写入失败！");
        }
    }

    InputStream myInput = getAssets().open(fileName);
    file.createNewFile();
    OutputStream myOutput = new FileOutputStream(file, true);
    byte[] buffer = new byte[1024];
    int length;
    while ((length = myInput.read(buffer)) > 0) {
        myOutput.write(buffer, 0, length);
    }
    myOutput.flush();
    myOutput.close();
    myInput.close();
}