hellas2000 opened a new issue, #8907:
URL: https://github.com/apache/netbeans/issues/8907
### Apache NetBeans version
Apache NetBeans 27
### What happened
When using the NetBeans GUI Builder (Matisse) to set an icon for a component
(e.g., JMenuItem), the generated code uses:
new ImageIcon(getClass().getResource("/path/to/icon.png"))
This works in simple monolithic applications, but **fails in modular
projects (JPMS) or multi-module Maven/Gradle projects** where the icon resource
resides in a different module.
The issue is that `getClass().getResource()` performs a **class-relative
resource lookup**, which is subject to module encapsulation rules. If the
resource is in another module (even if on the classpath), it returns `null`,
causing a `NullPointerException` at runtime.
In contrast, `ClassLoader.getResource()` performs a **classpath-root
lookup** and can access resources across module boundaries (if the class loader
has visibility), making it more suitable for multi-module environments.
For example, this works:
new
ImageIcon(getClass().getClassLoader().getResource("alwaystech/alwaysswing/resources/images/misc_preferences.png"))
Note:
- No leading `/` when using `ClassLoader.getResource()`
- The path is relative to the classpath root
Suggested Improvement:
Please modify the GUI Builder code generator to:
1. Detect if the project is modular or multi-module, OR
2. Provide an option in the IDE settings to prefer
`ClassLoader.getResource()` over `getClass().getResource()`
3. Generate code using `getClassLoader().getResource(path)` (without leading
`/`) when appropriate
Alternatively, allow users to define a custom resource loading strategy for
icons in GUI forms.
This change would improve compatibility with modern Java project structures
and avoid runtime resource loading failures.
Steps to Reproduce:
1. Create a multi-module Maven/Gradle project
2. Place an icon (e.g., misc_preferences.png) in resources of module A
3. In module B, use GUI Builder to set the icon for a JMenuItem
4. Run the application → Icon fails to load (NPE or blank)
### Language / Project Type / NetBeans Component
_No response_
### How to reproduce
1. Create a multi-module Maven/Gradle project
2. Place an icon (e.g., misc_preferences.png) in resources of module A
3. In module B, use GUI Builder to set the icon for a JMenuItem
4. Run the application → Icon fails to load (NPE or blank)
### Did this work correctly in an earlier version?
No / Don't know
### Operating System
debian12.5
### JDK
jdk25
### Apache NetBeans packaging
Apache NetBeans binary zip
### Anything else
_No response_
### Are you willing to submit a pull request?
No
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