私は現在、友人と一緒にゲームに取り組んでいますが、ゲームに保存機能を実装することでいくつかの問題が発生しました。しかし、配列から特定の値を取得しようとするたびに NullPointerExceptions が発生し続けます。
SaveGame.java:
public class SaveGame {
static int newValue;
//unnecessary stuff hidden...
public static void SaveGame() {
//The class which uses getTokenPositionList()
}
//Saves the positioning of the tokens within a String
static String getTokenPositionList() {
String tokenPositionList = "";
for (int row = 0; row < 10; row++) {
for (int col = 0; col < 10; col++) {
tokenPositionList = tokenPositionList + KodeKs.KodeKsData.getKodeKsData(row, col);
}
}
return tokenPositionList;
} // end getTokenPositionList()
}
KodeKs.java:
public class KodeKs extends JPanel {
public KodeKs() {
//lots of unessecary stuff hidden
public static class KodeKsData {
public static int[][] board;
public KodeKsData() {
board = new int[10][10];
setUpGame();
}
public static int getKodeKsData(int row, int col) {
return board[row][col];
}
//more stuff hidden
}
}
}
そして、これは私がこのようなものを実行したときに得られるエラーコードです:
> Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException > at KodeKs$KodeKsData.getKodeKsData(KodeKs.java:597) at > SaveGame.getTokenPositionList(SaveGame.java:61) at > SaveGame.SaveGame(SaveGame.java:33) at > KodeKsToolBar$3.actionPerformed(KodeKsToolBar.java:48) at > javax.swing.AbstractButton.fireActionPerformed(Unknown Source) at > javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source) at > javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source) at > javax.swing.DefaultButtonModel.setPressed(Unknown Source) at > javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown > Source) at java.awt.Component.processMouseEvent(Unknown Source) at > javax.swing.JComponent.processMouseEvent(Unknown Source) at > java.awt.Component.processEvent(Unknown Source) at > java.awt.Container.processEvent(Unknown Source) at > java.awt.Component.dispatchEventImpl(Unknown Source) at > java.awt.Container.dispatchEventImpl(Unknown Source) at > java.awt.Component.dispatchEvent(Unknown Source) at > java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source) at > java.awt.LightweightDispatcher.processMouseEvent(Unknown Source) at > java.awt.LightweightDispatcher.dispatchEvent(Unknown Source) at > java.awt.Container.dispatchEventImpl(Unknown Source) at > java.awt.Window.dispatchEventImpl(Unknown Source) at > java.awt.Component.dispatchEvent(Unknown Source) at > java.awt.EventQueue.dispatchEventImpl(Unknown Source) at > java.awt.EventQueue.access$200(Unknown Source) at > java.awt.EventQueue$3.run(Unknown Source) at > java.awt.EventQueue$3.run(Unknown Source) at > java.security.AccessController.doPrivileged(Native Method) at > java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown > Source) at > java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown > Source) at java.awt.EventQueue$4.run(Unknown Source) at > java.awt.EventQueue$4.run(Unknown Source) at > java.security.AccessController.doPrivileged(Native Method) at > java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown > Source) at java.awt.EventQueue.dispatchEvent(Unknown Source) at > java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source) > at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source) > at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown > Source) at java.awt.EventDispatchThread.pumpEvents(Unknown Source) > at java.awt.EventDispatchThread.pumpEvents(Unknown Source) at > java.awt.EventDispatchThread.run(Unknown Source)