Java：来自class.getResource（...）的NullPointerException [英] Java: NullPointerException from class.getResource( ... )

问题描述

我正在编写一个小应用程序，当我尝试创建一个ImageIcon时，我总是遇到异常。这个例外代码引起了异常：

I was writing a small application and when I tried to create an ImageIcon I always got an exception. The exception was caused by this line of code:

prayerLevel.setIcon(new ImageIcon(getClass().getResource("/icons/icon_prayer.png")));

现在我的程序中，文件夹/ icons /确实存在。我不知道它是否有所不同但是类文件在一个包中，其中icons文件夹在项目文件夹中（当你看到bin和src文件夹时）。

Now within my program, the folder /icons/ does exist. I don't know if it makes the difference but the class file is within a package, where as the icons folder is within the project folder (when you would see the bin and src folder).

我已经四处寻找，我找不到可以帮助我解决问题的解决方案。也许你们中的任何人都可以提供帮助？

I have looked around for a bit and I couldn't find a solution that could help me solve the problem. Perhaps any of you guys could help?

编辑：有人要求我的文件夹层次结构：

someone asked for my folder hierarchy:

我知道类文件不在同一个文件夹作为图标，但我已经创建了应用程序，我必须从不同的文件夹加载文件和/文件夹/总是用来工作。

I know the class file is not in the same folder as the icons are, but I've made applications where I had to load files from a different folder and doing /folder/ always used to work.

编辑2：

System.out.println(getClass().getResource("/icons/icon_prayer.png") == null);

打印为真。

推荐答案

我相信NPE是从 ImageIcon 构造函数抛出的，因为 getResource 正在返回空。

I believe the NPE is being thrown from the ImageIcon constructor as getResource is returning null.

尝试以下方法：

getClass().getClassLoader().getResource("/icons/icon_prayer.png")

或：

ClassLoader.getSystemResource("/icons/icon_prayer.png")

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