Android 判断现在系统存储器是“手机存储”还是“SD存储”

import android.os.storage.StorageManager;

String fileDir = null;
            StorageManager storageManager = (StorageManager)mContext.getSystemService(Context.STORAGE_SERVICE);
            if (null == storageManager) {
            fileDir = Environment.getExternalStorageDirectory().getPath();
            } else {
            fileDir = storageManager.getDefaultPath();
            }
            if(fileDir.equals("/storage/sdcard1")){
            showString = getString(R.string.toast_phone_insufficient_space);
            }else{
            showString = getString(R.string.toast_sdcard_insufficient_space);
            }