public void nextLevel() {
    boolean loaded = false;
    final GameBoard boardView = (GameBoard) this.findViewById(R.id.gameBoard);
    this.level++;

    AssetManager am = getResources().getAssets();

    try {
      List<String> allTutoLevels =
          new LinkedList<String>(Arrays.asList(am.list("levels/tutorial")));

      // if(addMsg){
      //    allTutoLevels.addAll(Arrays.asList(am.list("msg")));
      // }

      Log.d(TAG, allTutoLevels.toString());

      for (String name : allTutoLevels) {
        if (name.startsWith(this.level + ".")) {
          BufferedReader br =
              new BufferedReader(new InputStreamReader(am.open("levels/tutorial/" + name)));
          String line;
          String levelJSON = "";

          while ((line = br.readLine()) != null) {
            levelJSON += line + "\n";
          }

          br.close();

          game.initGame(
              levelJSON, boardView.getMeasuredWidth() / 60, boardView.getMeasuredHeight() / 60);
          loaded = true;
        }
      }
    } catch (IOException e) {
      e.printStackTrace();
    }

    if (!loaded) {
      Random r = new Random();

      List<String> allLevels = new ArrayList<>();

      try {
        allLevels = Arrays.asList(am.list("levels"));
      } catch (IOException e) {
      }

      if (r.nextBoolean() && !allLevels.isEmpty() && allLevels.size() != allDoneLevels.size()) {
        try {
          int nLevel;
          do {
            nLevel = r.nextInt(allLevels.size());
          } while (allDoneLevels.contains(allLevels.get(nLevel)));

          String name = allLevels.get(nLevel);
          BufferedReader br = new BufferedReader(new InputStreamReader(am.open("levels/" + name)));

          String line;
          String levelJSON = "";

          while ((line = br.readLine()) != null) {
            levelJSON += line + "\n";
          }

          br.close();

          allDoneLevels.add(name);

          game.initGame(
              levelJSON, boardView.getMeasuredWidth() / 60, boardView.getMeasuredHeight() / 60);
        } catch (IOException e) {
          this.game.initGame(
              level, boardView.getMeasuredWidth() / 60, boardView.getMeasuredHeight() / 60);
        }
      } else {
        this.game.initGame(
            level, boardView.getMeasuredWidth() / 60, boardView.getMeasuredHeight() / 60);
      }
    }

    // am.close();

    boardView.setGame(this.game);
    boardView.invalidate();
    boardView.getHowdyShadeView().invalidate();

    Toast.makeText(this, this.level + "", Toast.LENGTH_SHORT).show();

    Log.i(
        TAG,
        "Max tiles : "
            + (boardView.getMeasuredWidth() / 60) * (boardView.getMeasuredHeight() / 60));
  }
  /**
   * コンストラクタ ここでファイルからデータを読み込んでいる
   *
   * @param in_gl OpenGLコマンド群をカプセル化したクラス
   * @param in_texPool テクスチャ管理クラス
   * @param i_provider ファイルデータプロバイダ
   * @param mqoFile 読み込みファイル
   * @param scale モデルの倍率
   * @param isUseVBO 頂点配列バッファを使用するかどうか
   */
  protected KGLMetaseq(
      GL10 gl, KGLTextures in_texPool, AssetManager am, String msqname, float scale) {
    super(in_texPool, am, scale);
    //	targetMQO = in_moq;
    material mats[] = null;
    InputStream fis = null;
    // InputStreamReader isr = null ;
    // BufferedReader br = null;
    multiInput br = null;
    String chankName[] = null;
    GLObject glo = null;
    ArrayList<GLObject> globjs = new ArrayList<GLObject>();
    try {
      fis = am.open(msqname);
      // isr = new InputStreamReader(fis) ;
      // br = new BufferedReader(isr);
      br = new multiInput(fis);
      while ((chankName = Chank(br, false)) != null) {
        /*
         * for( int i = 0 ; i < chankName.length ; i++ ) {
         * System.out.print(chankName[i]+" ") ; } System.out.println() ;
         */
        if (chankName[0].trim().toUpperCase().equals("MATERIAL")) {
          try {
            mats = new material[Integer.parseInt(chankName[1])];
            for (int m = 0; m < mats.length; m++) {
              mats[m] = new material();
              mats[m].set(br.readLine().trim());
              // Log.i("KGLMetaseq", "Material(" + m+") :" + mats[m].toString());
            }
          } catch (Exception mat_e) {
            Log.e("KGLMetaseq", "MQOファイル Materialチャンク読み込み例外発生 " + mat_e.getMessage());
            throw new KGLException(mat_e);
          }
        }
        try {
          if (chankName[0].trim().toUpperCase().equals("OBJECT")) {
            objects object = new objects();
            object.set(chankName[1], br, scale);

            // System.out.println(object.toString()) ;
            if (object.face == null) {
              continue; // 面情報のないオブジェクトは飛ばす
            }
            glo = makeObjs(gl, mats, object);
            if (glo != null) {
              globjs.add(glo);
            }
          }
        } catch (Exception obj_e) {
          Log.e(
              "KGLMetaseq", "MQOファイル Object[" + chankName[1] + "]チャンク読み込み例外発生 " + obj_e.toString());
          throw new KGLException(obj_e);
        }
      }
      br.close(); // 読み込み終了
      br = null;
      glObj = globjs.toArray(new GLObject[0]);
    } catch (Exception e) {
      e.printStackTrace();
    } finally {
      try {
        if (br != null) br.close();
      } catch (IOException e) {
        e.printStackTrace();
      }
    }
  }