BufferedReader從txt文件轉換爲陣列

Question

在物理電話上測試Android應用程序。我使用Android Studio。我不知道爲什麼我得到java.lang.IndexOutOfBoundsException：

Process: com.packtpub.libgdx.outtacluck.android, PID: 27731 
java.lang.IndexOutOfBoundsException: Invalid index 4, size is 0 
     at java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:255) 
     at java.util.ArrayList.get(ArrayList.java:308) 
     at com.packtpub.libgdx.outtacluck.game.WorldController.highScoreCheck(WorldController.java:1048) 
     at com.packtpub.libgdx.outtacluck.game.WorldController.update(WorldController.java:375) 
     at com.packtpub.libgdx.outtacluck.screens.GameScreen.render(GameScreen.java:40) 
     at com.packtpub.libgdx.outtacluck.screens.DirectedGame.render(DirectedGame.java:67) 
     at com.badlogic.gdx.backends.android.AndroidGraphics.onDrawFrame(AndroidGraphics.java:424) 
     at android.opengl.GLSurfaceView$GLThread.guardedRun(GLSurfaceView.java:1531) 
     at android.opengl.GLSurfaceView$GLThread.run(GLSurfaceView.java:1248) 

但我從來都沒有被添加到scoresData陣列

這裏的類。我宣佈它一樣

public class ScoreManager { 


public List<Double> scoresData = new ArrayList<Double>(); 


public ScoreManager() 
{ 
try{ 
     // Open the file that is the first 
     FileInputStream fstream = new FileInputStream(Constants.SCORES_TRACKER); 

     // Use DataInputStream to read binary NOT text. 
     BufferedReader br = new BufferedReader(new InputStreamReader(fstream)); 

     String strLine; 


     //Read File Line By Line 
     while ((strLine = br.readLine()) != null) { 
      // Add number from file to list 
      scoresData.add(Double.parseDouble(strLine)); 
     } 
     //Close the input stream 
     br.close(); 

     System.out.println(scoresData); 
    }catch (Exception e){ 
     e.printStackTrace(); 
     } 
    System.out.println("scoresData.size is " + scoresData.size()); 

    } 

public static double parseInt(String input) throws NullPointerException, ParseException{ 
    if(input == null){ 
     throw new NullPointerException(); 
    } 

    input = input.trim(); 

    NumberFormat numberFormat = NumberFormat.getNumberInstance(Locale.US); 
    ParsePosition parsePosition = new ParsePosition(0); 
    Number number = numberFormat.parse(input, parsePosition); 

    if(parsePosition.getIndex() != input.length()){ 
     throw new ParseException("Invalid input", parsePosition.getIndex()); 
    } 

    return number.doubleValue(); 
} 


public int getArrayElement(int index) 
{ 
    if(scoresData.isEmpty()) 
    { 
     System.out.println("scoresData is empty"); 
     return 0; 
    } 
    else 
    { 
     double x = scoresData.get(index); 
     return (int) x; 
    } 
    } 
} 

Answer 1

我剛剛測試了這一點，它填充arraylist就好了。根據上述代碼，我認爲您的數據列表聲明不正確。嘗試這個。

List<Double> scoresData = new ArrayList<Double>();