Question

I was confused using the said method because while loading some properties file people are following a different approaches…

Properties prop 
 = new Properties(new FileInputStream(new File("<path of the properties file>"));

and few are using..

Properties prop 
 = new Properties(getClass().getResourceAsStream("<path of the properties file>"));

Which one to use when?

Answer 1

getResourceAsStream searchs you classpath for the given file/resource and it can also provide InputStreams of resources from inside a JAR.

So, if your properties exist in some folder in the physical filesystem (e.g. user folder, …) use FileInputStream and if the file is embedded in your classpath (e.g. as a resource inside the JAR) use getResourceAsStream.