加载图像时，枚举抛出错误 [英] Enum Throws Error when loading Image
问题描述
这都是Java语言。主要问题是在Enum类中我声明了许多不同的枚举。声明每个图像时，都有一个图像路径，该路径告诉构造函数从何处加载图像。但是，当我调用我创建的enum.getImage（）方法时，它将引发ExceptionInInitializerError。这是Enum类：
This is all in Java. The main problem is that inside the Enum class I have many different enums declared. When each is declared there is an image path that tells the constructor where to load the image from. But when I call the enum.getImage() method I created, it throws an ExceptionInInitializerError. Here is the Enum class:
import java.awt.Image;
import javax.swing.ImageIcon;
import java.util.HashMap;
public enum Cards {
ACE_HEART(11,1,"acehearts.png"), ACE_SPADE(11,2,"acespades.png"), ACE_CLUB(11,3,"aceclubs.png"), ACE_DIAMOND(11,4,"acediamonds.png"),
TWO_HEART(2,5,"twohearts.png"), TWO_SPADE(2,6,"twospades.png"), TWO_CLUB(2,7,"twoclubs.png"), TWO_DIAMOND(2,8,"twodiamonds.png"),
THREE_HEART(3,9,"threehearts.png"), THREE_SPADE(3,10,"threespades.png"), THREE_CLUB(3,11,"threeclubs.png"), THREE_DIAMOND(3,12,"threediamonds.png"),
FOUR_HEART(4,13,"fourhearts.png"), FOUR_SPADE(4,14,"fourspades.png"), FOUR_CLUB(4,15,"fourclubs.png"), FOUR_DIAMOND(4,16,"fourdiamonds.png"),
FIVE_HEART(5,17,"fivehearts.png"), FIVE_SPADE(5,18,"fivespades.png"), FIVE_CLUB(5,19,"fiveclubs.png"), FIVE_DIAMOND(5,20,"fivediamonds.png"),
SIX_HEART(6,21,"sixhearts.png"), SIX_SPADE(6,22,"sixspades.png"), SIX_CLUB(6,23,"sixclubs.png"), SIX_DIAMOND(6,24,"sixdiamonds.png"),
SEVEN_HEART(7,25,"sevenhearts.png"), SEVEN_SPADE(7,26,"sevenspades.png"), SEVEN_CLUB(7,27,"sevenclubs.png"), SEVEN_DIAMOND(7,28,"sevendiamonds.png"),
EIGHT_HEART(8,29,"eighthearts.png"), EIGHT_SPADE(8,30,"eightspades.png"), EIGHT_CLUB(8,31,"eightclubs.png"), EIGHT_DIAMOND(8,32,"eightdiamonds.png"),
NINE_HEART(9,33,"ninehearts.png"), NINE_SPADE(9,34,"ninespades.png"), NINE_CLUB(9,35,"nineclubs.png"), NINE_DIAMOND(9,36,"ninediamonds.png"),
TEN_HEART(10,37,"tenhearts.png"), TEN_SPADE(10,38,"tenspades.png"), TEN_CLUB(10,39,"tenclubs.png"), TEN_DIAMOND(10,40,"tendiamonds.png"),
JACK_HEART(10,41,"jackhearts.png"), JACK_SPADE(10,42,"jackspades.png"), JACK_CLUB(10,43,"jackclubs.png"), JACK_DIAMOND(10,44,"jackdiamonds.png"),
QUEEN_HEART(10,45,"queenhearts.png"), QUEEN_SPADE(10,46,"queenspades.png"), QUEEN_CLUB(10,47,"queenclubs.png"), QUEEN_DIAMOND(10,48,"queendiamonds.png"),
KING_HEART(10,49,"kinghearts.png"), KING_SPADE(10,50,"kingspades.png"), KING_CLUB(10, 51, "kingclubs.png"), KING_DIAMOND(10, 52, "kingdiamonds.png");
int value,id;
Image image;
private HashMap<Integer,Cards> cardmap = new HashMap<Integer,Cards>();
public void setMap() {
for(Cards c : Cards.values()) {
cardmap.put(c.getValue(),c);
}
}
private Cards(int value, int id, String imagepath) {
this.value = value;
this.id = id;
ImageIcon i = new ImageIcon(this.getClass().getResource("img/" + imagepath));
Image image = i.getImage();
this.image = image;
}
public Image getImage() {
return image;
}
public int getId() {
return id;
}
public int getValue() {
return value;
}
public Cards getEnum(int id) {
return cardmap.get(id);
}
}
如果您对错误有任何想法（否我不是在问代码）你能解释我在做什么错吗？
If you have any ideas on what is wrong (no I'm not asking for code) could you explain what I am doing wrong?
编辑：完整堆栈跟踪：
Exception in thread "AWT-EventQueue-0" java.lang.ExceptionInInitializerError
at blackjack.Board.paint(Board.java:22)
at javax.swing.JComponent.paintChildren(JComponent.java:870)
at javax.swing.JComponent.paint(JComponent.java:1046)
at javax.swing.JComponent.paintChildren(JComponent.java:870)
at javax.swing.JComponent.paint(JComponent.java:1046)
at javax.swing.JLayeredPane.paint(JLayeredPane.java:567)
at javax.swing.JComponent.paintChildren(JComponent.java:870)
at javax.swing.JComponent.paintToOffscreen(JComponent.java:5139)
at javax.swing.RepaintManager$PaintManager.paintDoubleBuffered(RepaintManager.java:1523)
at javax.swing.RepaintManager$PaintManager.paint(RepaintManager.java:1454)
at javax.swing.RepaintManager.paint(RepaintManager.java:1257)
at javax.swing.JComponent.paint(JComponent.java:1023)
at java.awt.GraphicsCallback$PaintCallback.run(GraphicsCallback.java:21)
at sun.awt.SunGraphicsCallback.runOneComponent(SunGraphicsCallback.java:60)
at sun.awt.SunGraphicsCallback.runComponents(SunGraphicsCallback.java:97)
at java.awt.Container.paint(Container.java:1778)
at java.awt.Window.paint(Window.java:3390)
at javax.swing.RepaintManager$3.run(RepaintManager.java:825)
at javax.swing.RepaintManager$3.run(RepaintManager.java:802)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:802)
at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:745)
at javax.swing.RepaintManager.prePaintDirtyRegions(RepaintManager.java:725)
at javax.swing.RepaintManager.access$1000(RepaintManager.java:46)
at javax.swing.RepaintManager$ProcessingRunnable.run(RepaintManager.java:1668)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:672)
at java.awt.EventQueue.access$400(EventQueue.java:81)
at java.awt.EventQueue$2.run(EventQueue.java:633)
at java.awt.EventQueue$2.run(EventQueue.java:631)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:642)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)
Caused by: java.lang.NullPointerException
at javax.swing.ImageIcon.<init>(ImageIcon.java:181)
at blackjack.Cards.<init>(Cards.java:26)
at blackjack.Cards.<clinit>(Cards.java:7)
... 40 more
编辑2：
软件包的确切设置方式：
edit 2: Exactly how the package is set up:
大酒杯套餐。
内包装：21点类，董事会类，卡类，带有图像的img文件夹。
package blackjack. inside package: Blackjack class, Board class, Cards class, img folder with images.
推荐答案
您的枚举无法正确初始化，很可能是因为它在构造函数中引发了 NullPointerException 。
Your enum cannot be correctly initialized, most likely because it throws a NullPointerException in the constructor.
ImageIcon i = new ImageIcon(this.getClass().getResource("img/" + imagepath));
使用上面的语句，您正在寻找 img / imagepath 与枚举放在同一软件包中。使用 / 前缀路径
With the above statement, you are looking for img/imagepath in the same package as your enum. Prefix the path with / instead
ImageIcon i = new ImageIcon(this.getClass().getResource("/img/" + imagepath));
使它相对于类路径的根，因为我假设您的文件（ img 包）。
so that it is relative to the root of the classpath, as I assume your file (img package) is.
如果 / img 只是一个文件夹，您需要将其添加到您的类路径中。如果您使用的是Eclipse，请将其拖放到 src 文件夹中。
If /img is just a folder, you need to add it to your classpath. Drag and drop it into the src folder if you are on Eclipse.
这篇关于加载图像时，枚举抛出错误的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
