The simplest code would be like, keep your properties files into resources folder, either in src/main/resource or in src/test/resource. Then use below code to read properties files:
public class Utilities {
static {
rb1 = ResourceBundle.getBundle("fileNameWithoutExtension");
// do not use .properties extension
}
public static String getConfigProperties(String keyString) {
return rb1.getString(keyString);
}
}