동적 스프라이트 - 스레드의 예외 "AWT-EventQueue의-0"java.lang.NullPointerException이

Question

GameCanvas

AppleEnity - http://pastebin.com/ZVyL5fRm

, 엔티티 - bin.com/r4cqtr8B 붙여 넣기 (2 개 이상의 링크를 게시하지 못할 아직)

내 장면에 새로운 동적 스프라이트를 추가하는 데 문제가 있습니다.

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException 
at start.GameCanvas.dodaj(GameCanvas.java:65) 
at start.GameCanvas.keyPressed(GameCanvas.java:149) 
at java.awt.Component.processKeyEvent(Unknown Source) 
at java.awt.Component.processEvent(Unknown Source) 
at java.awt.Component.dispatchEventImpl(Unknown Source) 
at java.awt.Component.dispatchEvent(Unknown Source) 
at java.awt.KeyboardFocusManager.redispatchEvent(Unknown Source) 
at java.awt.DefaultKeyboardFocusManager.dispatchKeyEvent(Unknown Source) 
at java.awt.DefaultKeyboardFocusManager.preDispatchKeyEvent(Unknown Source) 
at java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(Unknown Source) 
at java.awt.DefaultKeyboardFocusManager.dispatchEvent(Unknown Source) 
at java.awt.Component.dispatchEventImpl(Unknown Source) 
at java.awt.Component.dispatchEvent(Unknown Source) 
at java.awt.EventQueue.dispatchEventImpl(Unknown Source) 
at java.awt.EventQueue.access$000(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) 

Answer 1

문제는이 라인에서 분명히 : (사과 무작위로 산란한다과) E를 누르면 날이 오류주는

jablka.add(new AppleEnity("resources/apple.png", random.nextInt(400), random.nextInt(400))); 

을 ...하지만이 약 jablka 변수 아니지만, 표현 :

:

random.nextInt(400) 

당신은 결코 random 변수를 초기화하지

private final Random random = new Random(); 

을 그리고 당신은 괜찮을거야 :

가와 위의 라인을 교체합니다. 또는 Math 개체 또는 RandomUtils 개체 만 사용하십시오.