[PATCH 1 of 2] Do not try to load empty files

[Wald Commits]

# HG changeset patch
# User Andre Heinecke <andre.heinecke at intevation.de>
# Date 1407774830 -7200
# Node ID 2fcbcc9bb59a6f7248921c699dbbe930cbc883fa
# Parent  7ede7904c8a5cd24b529bbe8391b86840f524efe
Do not try to load empty files.

    Aritfacts can be directly defined in the conf.xml nowadays so
    an xlink is no longer required to exist.

diff -r 7ede7904c8a5 -r 2fcbcc9bb59a artifacts/src/main/java/org/dive4elements/river/artifacts/context/RiverContextFactory.java
--- a/artifacts/src/main/java/org/dive4elements/river/artifacts/context/RiverContextFactory.java	Tue Aug 12 10:57:53 2014 +0200
+++ b/artifacts/src/main/java/org/dive4elements/river/artifacts/context/RiverContextFactory.java	Mon Aug 11 18:33:50 2014 +0200
@@ -261,6 +261,9 @@
 
             String xlink = tmp.getAttribute(XPATH_XLINK);
             xlink        = Config.replaceConfigDir(xlink);
+            if (xlink.isEmpty()) {
+                continue;
+            }
 
             File file = new File(xlink);
             if (!file.isFile() || !file.canRead()) {