Executable jar won't find the properties files

Question

I use this code in my program to load a properties file:

Properties properties = new Properties();
URL url = new App().getClass().getResource(PROPERTIES_FILE         


        

Answer 1

There are two workarounds:

1. Don't use the JAR as executabele JAR, but as library.

   java -cp .;filename.jar com.example.YourClassWithMain
   

2. Obtain the root location of the JAR file and get the properties file from it.

   URL root = getClass().getProtectionDomain().getCodeSource().getLocation();
   URL propertiesFile = new URL(root, "filename.properties");
   Properties properties = new Properties();
   properties.load(propertiesFile.openStream());
   

None of both are recommended approaches! The recommend approach is to have the following entry in JAR's /META-INF/MANIFEST.MF file:

Class-Path: .

Then it'll be available as classpath resource the usual way. You'll really have to instruct Maven somehow to generate the MANIFEST.MF file like that.