Resolving Null Return from class.getResource()

When using class.getResource() to retrieve a specific resource file, you may encounter unexpected null results. This article explores potential reasons behind this issue and provides an alternate solution.

The Problematic Line

The line of code in question attempts to locate the URL of the "GeoIP.dat" file:

URL url = ExchangeInterceptor.class.getResource("GeoIP.dat");

However, this call returns null, leaving you perplexed.

Investigating the Issue

After a thorough examination, it was discovered that the Resource Patterns設定 in Intellij Idea might be the culprit. Specifically, it ensures that class.getResource only recognizes and interpret resources that conform to the specified extensions.

Alternative Solution

To resolve this problem, verify the Resource Patterns setting by navigating to Settings > Build, Execution, Deployment > Compiler > Resource Patterns. Ensure that the extension of the resource you're trying to locate is included within the list of accepted patterns.

Once you've confirmed or added the correct extension, recompile your code to ensure that class.getResource can locate and load the desired resource file.