Nullpointerexception

[Jose05]

Hallo,
ich habe eine Methode geschrieben, die aus 16 Labels die Zahlen rausholt und in einen Array packt.
[CODE lang="xml" title="Die dazugehörige Fxml-Datei"]<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.geometry.Insets?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.layout.ColumnConstraints?>
<?import javafx.scene.layout.GridPane?>
<?import javafx.scene.layout.RowConstraints?>
<?import javafx.scene.text.Font?>

<GridPane alignment="CENTER" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="700.0" prefWidth="700.0" style="-fx-background-color: #888888; -fx-background-radius: 20px;" xmlns="http://javafx.com/javafx/17" xmlns:fx="http://javafx.com/fxml/1" fx:controller="pkg2048.RasterController">
<columnConstraints>
<ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
<ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
<ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
<ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
</columnConstraints>
<rowConstraints>
<RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
<RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
<RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
<RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
</rowConstraints>
<children>
<Label fx:id="lbl1" alignment="CENTER" contentDisplay="CENTER" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="150.0" prefWidth="150.0" style="-fx-background-color: #888888; -fx-background-radius: 20px;">
<GridPane.margin>
<Insets bottom="10.0" left="10.0" right="10.0" top="10.0" />
</GridPane.margin>
<font>
<Font name="MathJax_Math-BoldItalic" size="35.0" />
</font></Label>
<Label fx:id="lbl2" alignment="CENTER" contentDisplay="CENTER" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="150.0" prefWidth="150.0" style="-fx-background-color: #888888; -fx-background-radius: 20px;" GridPane.columnIndex="1">
<GridPane.margin>
<Insets bottom="10.0" left="10.0" right="10.0" top="10.0" />
</GridPane.margin>
<font>
<Font name="MathJax_Math-BoldItalic" size="35.0" />
</font></Label>
<Label fx:id="lbl3" alignment="CENTER" contentDisplay="CENTER" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="150.0" prefWidth="150.0" style="-fx-background-color: #888888; -fx-background-radius: 20px;" GridPane.columnIndex="2">
<GridPane.margin>
<Insets bottom="10.0" left="10.0" right="10.0" top="10.0" />
</GridPane.margin>
<font>
<Font name="MathJax_Math-BoldItalic" size="35.0" />
</font></Label>
<Label fx:id="lbl4" alignment="CENTER" contentDisplay="CENTER" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="150.0" prefWidth="150.0" style="-fx-background-color: #888888; -fx-background-radius: 20px;" textAlignment="CENTER" GridPane.columnIndex="3">
<GridPane.margin>
<Insets bottom="10.0" left="10.0" right="10.0" top="10.0" />
</GridPane.margin>
<font>
<Font name="MathJax_Math-BoldItalic" size="35.0" />
</font></Label>
<Label fx:id="lbl5" alignment="CENTER" contentDisplay="CENTER" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="150.0" prefWidth="150.0" style="-fx-background-color: #888888; -fx-background-radius: 20px;" GridPane.rowIndex="1">
<GridPane.margin>
<Insets bottom="10.0" left="10.0" right="10.0" top="10.0" />
</GridPane.margin>
<font>
<Font name="MathJax_Math-BoldItalic" size="35.0" />
</font></Label>
<Label fx:id="lbl6" alignment="CENTER" contentDisplay="CENTER" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="150.0" prefWidth="150.0" style="-fx-background-color: #888888; -fx-background-radius: 20px;" GridPane.columnIndex="1" GridPane.rowIndex="1">
<GridPane.margin>
<Insets bottom="10.0" left="10.0" right="10.0" top="10.0" />
</GridPane.margin>
<font>
<Font name="MathJax_Math-BoldItalic" size="35.0" />
</font></Label>
<Label fx:id="lbl7" alignment="CENTER" contentDisplay="CENTER" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="150.0" prefWidth="150.0" style="-fx-background-color: #888888; -fx-background-radius: 20px;" GridPane.columnIndex="2" GridPane.rowIndex="1">
<GridPane.margin>
<Insets bottom="10.0" left="10.0" right="10.0" top="10.0" />
</GridPane.margin>
<font>
<Font name="MathJax_Math-BoldItalic" size="35.0" />
</font></Label>
<Label fx:id="lbl8" alignment="CENTER" contentDisplay="CENTER" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="150.0" prefWidth="150.0" style="-fx-background-color: #888888; -fx-background-radius: 20px;" GridPane.columnIndex="3" GridPane.rowIndex="1">
<GridPane.margin>
<Insets bottom="10.0" left="10.0" right="10.0" top="10.0" />
</GridPane.margin>
<font>
<Font name="MathJax_Math-BoldItalic" size="35.0" />
</font></Label>
<Label fx:id="lbl9" alignment="CENTER" contentDisplay="CENTER" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="150.0" prefWidth="150.0" style="-fx-background-color: #888888; -fx-background-radius: 20px;" GridPane.rowIndex="2">
<GridPane.margin>
<Insets bottom="10.0" left="10.0" right="10.0" top="10.0" />
</GridPane.margin>
<font>
<Font name="MathJax_Math-BoldItalic" size="35.0" />
</font></Label>
<Label fx:id="lbl10" alignment="CENTER" contentDisplay="CENTER" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="150.0" prefWidth="150.0" style="-fx-background-color: #888888; -fx-background-radius: 20px;" GridPane.columnIndex="1" GridPane.rowIndex="2">
<GridPane.margin>
<Insets bottom="10.0" left="10.0" right="10.0" top="10.0" />
</GridPane.margin>
<font>
<Font name="MathJax_Math-BoldItalic" size="35.0" />
</font></Label>
<Label fx:id="lbl11" alignment="CENTER" contentDisplay="CENTER" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="150.0" prefWidth="150.0" style="-fx-background-color: #888888; -fx-background-radius: 20px;" GridPane.columnIndex="2" GridPane.rowIndex="2">
<GridPane.margin>
<Insets bottom="10.0" left="10.0" right="10.0" top="10.0" />
</GridPane.margin>
<font>
<Font name="MathJax_Math-BoldItalic" size="35.0" />
</font></Label>
<Label fx:id="lbl12" alignment="CENTER" contentDisplay="CENTER" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="150.0" prefWidth="150.0" style="-fx-background-color: #888888; -fx-background-radius: 20px;" GridPane.columnIndex="3" GridPane.rowIndex="2">
<GridPane.margin>
<Insets bottom="10.0" left="10.0" right="10.0" top="10.0" />
</GridPane.margin>
<font>
<Font name="MathJax_Math-BoldItalic" size="35.0" />
</font></Label>
<Label fx:id="lbl13" alignment="CENTER" contentDisplay="CENTER" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="150.0" prefWidth="150.0" style="-fx-background-color: #888888; -fx-background-radius: 20px;" GridPane.rowIndex="3">
<GridPane.margin>
<Insets bottom="10.0" left="10.0" right="10.0" top="10.0" />
</GridPane.margin>
<font>
<Font name="MathJax_Math-BoldItalic" size="35.0" />
</font></Label>
<Label fx:id="lbl14" alignment="CENTER" contentDisplay="CENTER" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="150.0" prefWidth="150.0" style="-fx-background-color: #888888; -fx-background-radius: 20px;" GridPane.columnIndex="1" GridPane.rowIndex="3">
<GridPane.margin>
<Insets bottom="10.0" left="10.0" right="10.0" top="10.0" />
</GridPane.margin>
<font>
<Font name="MathJax_Math-BoldItalic" size="35.0" />
</font></Label>
<Label fx:id="lbl15" alignment="CENTER" contentDisplay="CENTER" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="150.0" prefWidth="150.0" style="-fx-background-color: #888888; -fx-background-radius: 20px;" GridPane.columnIndex="2" GridPane.rowIndex="3">
<GridPane.margin>
<Insets bottom="10.0" left="10.0" right="10.0" top="10.0" />
</GridPane.margin>
<font>
<Font name="MathJax_Math-BoldItalic" size="35.0" />
</font></Label>
<Label fx:id="lbl16" alignment="CENTER" contentDisplay="CENTER" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="150.0" prefWidth="150.0" style="-fx-background-color: #888888; -fx-background-radius: 20px;" GridPane.columnIndex="3" GridPane.rowIndex="3">
<GridPane.margin>
<Insets bottom="10.0" left="10.0" right="10.0" top="10.0" />
</GridPane.margin>
<font>
<Font name="MathJax_Math-BoldItalic" size="35.0" />
</font></Label>

</children>
</GridPane>
[/CODE]

[CODE lang="java" title="Hier die wichtige Klasse"]package pkg2048;

public class RasterController implements Initializable
{

@FXML
public Label lbl1;
@FXML
public Label lbl2;
@FXML
public Label lbl3;
@FXML
public Label lbl4;
@FXML
public Label lbl5;
@FXML
public Label lbl6;
@FXML
public Label lbl7;
@FXML
public Label lbl8;
@FXML
public Label lbl9;
@FXML
public Label lbl10;
@FXML
public Label lbl11;
@FXML
public Label lbl12;
@FXML
public Label lbl13;
@FXML
public Label lbl14;
@FXML
public Label lbl15;
@FXML
public Label lbl16;

int[] sp0 = new int[4];
int[] sp1 = new int[4];
int[] sp2 = new int[4];
int[] sp3 = new int[4];
int summand;
int[] anfangszahlen = new int[4];
int[] zahlen = new int[16];

Label[] lbl = new Label[16];

@Override
public void initialize(URL url, ResourceBundle rb)
{
for (int i = 0; i < 16; i++)
{
lbl.setText(String.valueOf(i));
}
}

public void teileInSpalten(KeyCode kc)
{
if(kc == KeyCode.UP)
{
anfangszahlen[0] = 0;
anfangszahlen[1] = 1;
anfangszahlen[2] = 2;
anfangszahlen[3] = 3;
summand = 4;
}

if(kc == KeyCode.DOWN)
{
anfangszahlen[0] = 12;
anfangszahlen[1] = 13;
anfangszahlen[2] = 14;
anfangszahlen[3] = 15;
summand = -4;
}

if(kc == KeyCode.LEFT)
{
anfangszahlen[0] = 0;
anfangszahlen[1] = 4;
anfangszahlen[2] = 8;
anfangszahlen[3] = 12;
summand = -1;
}

if(kc == KeyCode.RIGHT)
{
anfangszahlen[0] = 3;
anfangszahlen[1] = 7;
anfangszahlen[2] = 11;
anfangszahlen[3] = 15;
summand = 1;
}

getInteger();

for (int i = 0; i < 4; i++)
{
sp0 = zahlen[anfangszahlen[0] + summand * i];
}

for (int i = 0; i < 4; i++)
{
sp1 = zahlen[anfangszahlen[1] + summand * i];
}

for (int i = 0; i < 4; i++)
{
sp2 = zahlen[anfangszahlen[2] + summand * i];
}

for (int i = 0; i < 4; i++)
{
sp3 = zahlen[anfangszahlen[3] + summand * i];
}

System.out.println(java.util.Arrays.toString(sp0));
System.out.println(java.util.Arrays.toString(sp1));
System.out.println(java.util.Arrays.toString(sp2));
System.out.println(java.util.Arrays.toString(sp3));

}
}[/CODE]

Beim ausführen der Methode teileSpalten() bekomme ich jedoch eine Nullpointerexception. Könnte jemand mir helfen? Braucht ihr noch mehr Informationen?
Danke schonmal

 

[mihe7]

Ich würde eher sagen, die NPE tritt in Zeile 54 auf.

 

[Jose05]

Ich wollte nicht unnötig viel Code einfügen, die Labels werden vor Zeile 52 in den Array eingefügt.

 

[Jose05]

Ach, mir fällt gerade auf, ihr wisst gar nicht was die Methode getInteger() macht. Diese Methode holt die Werte aus den Labels und fügt sie in den Array zahlen ein. Diese Mehtode funktioniert aber.

 

[mihe7]

Machen wir es andesrum: im Stacktrace der Exception ist normalerweise auch angegeben, wo genau die NPE auftritt, d. h. irgendwo solltest Du einen Hinweis auf eben die Methode inkl. Zeilennummer bekommen. An der Stelle wäre auch zu finden, was null sein muss.

 

[Jose05]

Ich habe jetzt herausgefunden, dass das Problem während des zugreifen auf den Label-Array auftritt. Allerdings habe ich folgende Methode in der initialize-Methode aufgerufen:

    public void fuelleDenArray()
    {
        lbl[0] = lbl1;
        lbl[1] = lbl2;
        lbl[2] = lbl3;
        lbl[3] = lbl4;
        lbl[4] = lbl5;
        lbl[5] = lbl6;
        lbl[6] = lbl7;
        lbl[7] = lbl8;
        lbl[8] = lbl9;
        lbl[9] = lbl10;
        lbl[10] = lbl11;
        lbl[11] = lbl12;
        lbl[12] = lbl13;
        lbl[13] = lbl14;
        lbl[14] = lbl15;
        lbl[15] = lbl16;
    }

Ich weiß nicht was das Problem ist.

 

[thecain]

Das Problem liegt im Moment vor allem daran, dass du keinen Stacktrace und nur die Hälfte des Codes gepostet hast. Wie sollen wir so einen Fehler finden?

 

[Jose05]

Ich habe den Fehler jetzt schon selbst gefunden. Aber danke für euere Bemühungen.