java maven imageIcon [重复]

Question

我在 netbeans 中使用 maven，并且我有一个框架，我想在其中添加徽标。 在 jframe 的设计部​​分，我可以看到徽标，但是当我运行该应用程序时，它给了我一个错误，提示该位置为空。但是我的代码在没有图标的情况下工作。

ps 我已经通过 netbeans 的 gui builder 在标签中添加了图标！

这是错误：

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException: Cannot invoke "java.net.URL.toExternalForm()" because "location" is null
    at java.desktop/javax.swing.ImageIcon.<init>(ImageIcon.java:217)
    at com.mycompany.moduleborne.BorneMain.initComponents(BorneMain.java:416)
    at com.mycompany.moduleborne.BorneMain.<init>(BorneMain.java:77)
    at com.mycompany.moduleborne.Initt.jButton1ActionPerformed(Initt.java:117)
    at com.mycompany.moduleborne.Initt.access$000(Initt.java:18)
    at com.mycompany.moduleborne.Initt$1.actionPerformed(Initt.java:50)
    at java.desktop/javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1972)
    at java.desktop/javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2313)
    at java.desktop/javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:405)
    at java.desktop/javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:262)
    at java.desktop/javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:279)
    at java.desktop/java.awt.Component.processMouseEvent(Component.java:6617)
    at java.desktop/javax.swing.JComponent.processMouseEvent(JComponent.java:3342)
    at java.desktop/java.awt.Component.processEvent(Component.java:6382)
    at java.desktop/java.awt.Container.processEvent(Container.java:2264)
    at java.desktop/java.awt.Component.dispatchEventImpl(Component.java:4993)
    at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2322)
    at java.desktop/java.awt.Component.dispatchEvent(Component.java:4825)
    at java.desktop/java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4934)
    at java.desktop/java.awt.LightweightDispatcher.processMouseEvent(Container.java:4563)
    at java.desktop/java.awt.LightweightDispatcher.dispatchEvent(Container.java:4504)
    at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2308)
    at java.desktop/java.awt.Window.dispatchEventImpl(Window.java:2773)
    at java.desktop/java.awt.Component.dispatchEvent(Component.java:4825)
    at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:772)
    at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:721)
    at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:715)
    at java.base/java.security.AccessController.doPrivileged(AccessController.java:391)
    at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
    at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:95)
    at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:745)
    at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:743)
    at java.base/java.security.AccessController.doPrivileged(AccessController.java:391)
    at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
    at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:742)
    at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
    at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
    at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)
    at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)
    at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
    at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)

Answer 1

ma​​ven 下只有 java sources 位于 src/main/java/ 下。 另一方面，resources 位于 src/main/resources/ 下。

您可以在 Project Files 下简单地创建文件夹，没什么特别的。

文件名必须区分大小写。只有 Windows 不区分大小写。打包在 jar（zip 格式）中的编译产品区分大小写。 Linux 也是如此。