Revision 1747976

No functional changes. While reviewing Wai's patch for OFBIZ-7112 I noticed that he (re)used this pattern introduced earlier:
  (resource == null || resource.length() <= 0)
From Java spec. a String, Collection, Map or CharSequence can't have a negative length, so the pattern above can be reduced to 
  (resource == null || resource.length() == 0)
which can be replaced using 
  UtilValidate.isEmpty()
I checked, there are several other occurrences of this pattern (some very old, I guess most were routinely copied from an initial occurrence). I decided to replace all of them, here they are.

I did that already long ago for the 
  (resource == null || resource.length() == 0)
pattern. It remains 4 of them. Three are justified (because of the dependency on base component or because using isEmpty() on Object is disputable for performance reasons). I took care of the remaining one right aways (in SplashScreen.java)