How to add Resources Folder, Properties at Runtime into IntelliJ classpath? Adding Property files to Classpath

Getting NullPointerException while reading Resource .properties file in Intellij IDE?

Do you have an issue loading resources files into your Intellij IDE? Having below errors?

Error: Could not find or load main class in intelliJ IDE
IntelliJ IDEA – getClass().getResource(“…”) return null
Unable to find .properties file at runtime
Not able to find resource file in classpath?
How to add a property file to a project/module at runtime in Intellij IDE?

Today while running tutorial how to read config.properties file in Java at runtime I got below error in IntelliJ IDE. Program runs very well without any issue in Eclipse IDE.

Exception in thread "main" java.lang.NullPointerException: inStream parameter is null
at java.base/java.util.Objects.requireNonNull(Objects.java:247)
at java.base/java.util.Properties.load(Properties.java:404)
at crunchify.com.tutorials.CrunchifyGetPropertyValues.getPropValues(CrunchifyGetPropertyValues.java:25)
at crunchify.com.tutorials.CrunchifyReadConfigMain.main(CrunchifyReadConfigMain.java:13)

It took me some time to fix this in IntelliJ IDE as I’m new to JetBrain's IntelliJ

Basically IntelliJ was giving me NullPointerException as it was not able to find resource folder at runtime.

Here is a code block.

String propFileName = "config.properties";
                
InputStream inputStream = getClass().getClassLoader().getResourceAsStream(propFileName);

prop.load(inputStream);          <========= NPE here while loading config.properties file

if (inputStream == null) {
        throw new FileNotFoundException("property file '" + propFileName + "' not found in the classpath");
}