[PATCH] Avoid NPE if river is not accessible

[Wald Commits]

# HG changeset patch
# User "Tom Gottfried <tom at intevation.de>"
# Date 1411744971 -7200
# Node ID f5461750e5c7ec97e044aa8bb65d5183b3a9859f
# Parent  b9fa8124583cf0558269f07a6db02573a90a599f
Avoid NPE if river is not accessible.

diff -r b9fa8124583c -r f5461750e5c7 artifacts/src/main/java/org/dive4elements/river/exports/injector/PNPInjector.java
--- a/artifacts/src/main/java/org/dive4elements/river/exports/injector/PNPInjector.java	Fri Sep 26 14:22:37 2014 +0200
+++ b/artifacts/src/main/java/org/dive4elements/river/exports/injector/PNPInjector.java	Fri Sep 26 17:22:51 2014 +0200
@@ -6,6 +6,7 @@
 import org.dive4elements.artifacts.ContextInjector;
 import org.dive4elements.river.artifacts.D4EArtifact;
 import org.dive4elements.river.artifacts.access.RiverAccess;
+import org.dive4elements.river.model.River;
 import org.dive4elements.river.model.Gauge;
 import org.w3c.dom.Document;
 import org.w3c.dom.Element;
@@ -37,14 +38,20 @@
             return;
         }
 
-        RiverAccess access = new RiverAccess((D4EArtifact)artifact);
         Double km = Double.valueOf(currentKm.toString());
         if (Double.isNaN(km) || Double.isInfinite(km)) {
             log.debug("current km is NAN or infinte. not injecting pnp.");
             return;
         }
+
+        River river = new RiverAccess((D4EArtifact)artifact).getRiver();
+        if (river == null) {
+            log.error("River not accessible from artifact. Not injecting PNP");
+            return;
+        }
+
         Gauge gauge =
-            access.getRiver().determineGaugeByStation(
+            river.determineGaugeByStation(
                 km - GAUGE_EPSILON,
                 km + GAUGE_EPSILON);