无法执行JAR文件

Question

我学习Java和我创建了我的第一个Java项目，这仅仅是UPI的演示应用程序。我的项目里面IDE完美运行（使用NetBeans IDE），但是当我创建的JAR文件，并尝试执行它，它显示了这个错误：

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
    at javax.swing.ImageIcon.<init>(Unknown Source)
    at swift.upi.LoginUI.initComponents(LoginUI.java:350)
    at swift.upi.LoginUI.<init>(LoginUI.java:27)
    at swift.upi.Welcome.nextBtnMouseClicked(Welcome.java:133)
    at swift.upi.Welcome.access$000(Welcome.java:14)
    at swift.upi.Welcome$1.mouseClicked(Welcome.java:67)
    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$500(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
    at java.awt.EventQueue$4.run(Unknown Source)
    at java.awt.EventQueue$4.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.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)

当我尝试执行任何事件，例如鼠标点击事件发生此错误。正因为如此，我才能够运行我的内部IDE项目。试图解释一个简单易用的方式问题和解决方案。我给的链​​接到我的项目为了方便起见，找到here。

谢谢。

Answer 1

作为暗示由卡洛斯的评论，问题是与在找到的LoginUI.java 350线称为图标/图像。

你的压缩项目内容与类的代码比较我想这个问题可能与文件名和它的情况。

• 代码说/swift/upi/Name logo.jpg
• 而该目录包含一个名为Name Logo.jpg

尝试改变l到L。而且 - 我建议你避免在文件名中的空格字符。