适用于 Netbeans，但不适用于 "outside"

Question

当我在 netbeans 中按 PLAY 时，这段代码工作完美，但当我构建它并启动 Jar 文件时，它不会。

private void SettingsMouseEntered(java.awt.event.MouseEvent evt) {                                      
ImageIcon Setting = new ImageIcon(getClass().getResource("/pic/settings-icon.png"));
Settings.setIcon(Setting);
     HooverBar.setText("Settings");
}                                     

private void SettingsMouseExited(java.awt.event.MouseEvent evt) {                                     
ImageIcon Setting = new ImageIcon(getClass().getResource("/pic/settings-icon-half.png"));
Settings.setIcon(Setting);
     HooverBar.setText("");
}                                    

private void SettingsMouseClicked(java.awt.event.MouseEvent evt) {                                      
    CardLayout card = (CardLayout)mainPanel.getLayout();
card.show(mainPanel,"gui5"); 
}

我不知道我做了什么？

当我使用 "Java -jar Knowhow.jar" 启动并将鼠标移到 "settings" 上时，我收到此错误

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
    at javax.swing.ImageIcon.<init>(Unknown Source)
    at AppPackage.GUI.SettingsMouseEntered(GUI.java:1755)
    at AppPackage.GUI.access00(GUI.java:26)
    at AppPackage.GUI.mouseEntered(GUI.java:278)
    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.retargetMouseEnterExit(Unknown Source)
    at java.awt.LightweightDispatcher.trackMouseEnterExit(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.access0(Unknown Source)
    at java.awt.EventQueue.run(Unknown Source)
    at java.awt.EventQueue.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain.doIntersectionPrivilege(Unknown Source)
    at java.security.ProtectionDomain.doIntersectionPrivilege(Unknown Source)
    at java.awt.EventQueue.run(Unknown Source)
    at java.awt.EventQueue.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain.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

您的图像未打包在您的 jar 中。你需要改变它。

我无法从你问题的细节中看出为什么会这样，但上下文是这样的：

getClass().getResource("/pic/settings-icon.png")

正在从您的类路径加载图像。那是来自类路径的每个元素。因此，您的 NetBeans 类路径与您的 java -jar 命令之一不同。

查看您的 NetBeans 中的运行配置以查看您的类路径并将命令的类路径映射到它。

适用于 Netbeans，但不适用于 "outside"

Works in Netbeans, but not "outside" of it

java

netbeans

jar