[安卓]在内存卡创建文件夹

来源：大牛直播内部代码

请求权限：

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

代码：

/**
 * 根据目录创建文件夹
 * @param context
 * @param cacheDir
 * @return
 */
public static File getOwnCacheDirectory(Context context, String cacheDir) {
    File appCacheDir = null;
    //判断sd卡正常挂载并且拥有权限的时候创建文件
    if ( Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState()) && hasExternalStoragePermission(context)) {
        appCacheDir = new File(Environment.getExternalStorageDirectory(), cacheDir);
        Log.i(TAG, "appCacheDir: " + appCacheDir);
    }
    if (appCacheDir == null || !appCacheDir.exists() && !appCacheDir.mkdirs()) {
        appCacheDir = context.getCacheDir();
    }
    return appCacheDir;
}

/**
 * 检查是否有权限
 * @param context
 * @return
 */
private static boolean hasExternalStoragePermission(Context context) {
    int perm = context.checkCallingOrSelfPermission("android.permission.WRITE_EXTERNAL_STORAGE");
    return perm == 0;
}