--- a/artifacts/src/main/java/org/dive4elements/river/artifacts/access/RangeAccess.java	Tue May 15 12:00:26 2018 +0200
+++ b/artifacts/src/main/java/org/dive4elements/river/artifacts/access/RangeAccess.java	Tue May 15 18:04:36 2018 +0200
@@ -8,25 +8,23 @@
 
 package org.dive4elements.river.artifacts.access;
 
-import gnu.trove.TDoubleArrayList;
-
+import org.apache.commons.lang.math.DoubleRange;
 import org.apache.log4j.Logger;
-
 import org.dive4elements.river.artifacts.D4EArtifact;
 import org.dive4elements.river.artifacts.WINFOArtifact;
-
+import org.dive4elements.river.utils.DoubleUtil;
 import org.dive4elements.river.utils.RiverUtils;
-import org.dive4elements.river.utils.DoubleUtil;
 
+import gnu.trove.TDoubleArrayList;
 
 /** For the moment, light-weight wrapper around RiverUtils. */
 // TODO employ 'Caching' like other Accesses, remove usage of RiverUtils.
-public class RangeAccess
-extends RiverAccess
-{
+public class RangeAccess extends RiverAccess {
     private static Logger log = Logger.getLogger(RangeAccess.class);
 
-    public static enum KM_MODE { RANGE, LOCATIONS, NONE };
+    public static enum KM_MODE {
+        RANGE, LOCATIONS, NONE
+    };
 
     /** The default step width between the start end end kilometer. */
     public static final double DEFAULT_KM_STEPS = 0.1;
@@ -44,32 +42,34 @@
     public RangeAccess() {
     }
 
-    public RangeAccess(D4EArtifact artifact) {
+    public RangeAccess(final D4EArtifact artifact) {
         super(artifact);
     }
 
-
     /** Evaluate the ld_mode data of artifact. */
     public KM_MODE getKmRangeMode() {
-        if (mode != null) {
-            return mode;
+        if (this.mode != null) {
+            return this.mode;
         }
-        String modeData = getString("ld_mode");
+        final String modeData = getString("ld_mode");
 
         if (modeData == null || modeData.length() == 0) {
-            mode = KM_MODE.NONE;
-        }
-        else if (modeData.equals("distance"))  {
-            mode = KM_MODE.RANGE;
-        }
-        else if (modeData.equals("locations")) {
-            mode = KM_MODE.LOCATIONS;
-        }
-        else {
-            mode = KM_MODE.NONE;
+            this.mode = KM_MODE.NONE;
+        } else if (modeData.equals("distance")) {
+            this.mode = KM_MODE.RANGE;
+        } else if (modeData.equals("locations")) {
+            this.mode = KM_MODE.LOCATIONS;
+        } else {
+            this.mode = KM_MODE.NONE;
         }
 
-        return mode;
+        return this.mode;
+    }
+
+    public final DoubleRange getRange() {
+        final double from = getFrom();
+        final double to = getTo();
+        return new DoubleRange(from, to);
     }
 
     /** Check if the calculation mode is Range. */
@@ -82,39 +82,28 @@
      * (from ld_locations data), null if not parameterized this way.
      */
     public double[] getLocations() {
-        String locationStr = getString("ld_locations");
+        final String locationStr = getString("ld_locations");
 
         if (locationStr == null || locationStr.length() == 0) {
             if (getArtifact() instanceof WINFOArtifact) {
-                WINFOArtifact winfo = (WINFOArtifact) getArtifact();
-                if (winfo.getReferenceStartKm() != null
-                    && winfo.getReferenceEndKms() != null
-                ) {
-                    return new double[]
-                        {
-                            winfo.getReferenceStartKm().doubleValue(),
-                            winfo.getReferenceEndKms()[0]
-                        };
-                }
-                else if (winfo.getReferenceStartKm() != null) {
-                    return new double[]
-                        {
-                            winfo.getReferenceStartKm().doubleValue(),
-                            winfo.getReferenceStartKm().doubleValue()
-                        };
+                final WINFOArtifact winfo = (WINFOArtifact) getArtifact();
+                if (winfo.getReferenceStartKm() != null && winfo.getReferenceEndKms() != null) {
+                    return new double[] { winfo.getReferenceStartKm().doubleValue(), winfo.getReferenceEndKms()[0] };
+                } else if (winfo.getReferenceStartKm() != null) {
+                    return new double[] { winfo.getReferenceStartKm().doubleValue(), winfo.getReferenceStartKm().doubleValue() };
                 }
             }
             return null;
         }
 
-        String[] tmp               = locationStr.split(" ");
-        TDoubleArrayList locations = new TDoubleArrayList();
+        final String[] tmp = locationStr.split(" ");
+        final TDoubleArrayList locations = new TDoubleArrayList();
 
-        for (String l: tmp) {
+        for (final String l : tmp) {
             try {
                 locations.add(Double.parseDouble(l));
             }
-            catch (NumberFormatException nfe) {
+            catch (final NumberFormatException nfe) {
                 log.debug(nfe.getLocalizedMessage(), nfe);
             }
         }
@@ -125,87 +114,89 @@
     }
 
     public boolean hasFrom() {
-        return from != null || (from = getDouble("ld_from")) != null;
+        return this.from != null || (this.from = getDouble("ld_from")) != null;
     }
 
     public boolean hasTo() {
-        return to != null || (to = getDouble("ld_to")) != null;
+        return this.to != null || (this.to = getDouble("ld_to")) != null;
     }
 
-    /* If left_to_right is set to true this returns
-     * the smaller value of from and to. */
-    public double getFrom(boolean left_to_right) {
+    /*
+     * If left_to_right is set to true this returns
+     * the smaller value of from and to.
+     */
+    public double getFrom(final boolean left_to_right) {
         if (!left_to_right) {
             return getFrom();
         }
-        double from = getFrom();
-        double to = getTo();
+        final double from = getFrom();
+        final double to = getTo();
         return from > to ? to : from;
     }
 
     /** Return ld_from data (in km). If not found, the min. */
     public double getFrom() {
-        if (from == null) {
-            from = getDouble("ld_from");
+        if (this.from == null) {
+            this.from = getDouble("ld_from");
         }
 
         if (log.isDebugEnabled()) {
-            log.debug("from from data: '" + from + "'");
+            log.debug("from from data: '" + this.from + "'");
         }
 
-        if (from == null) {
+        if (this.from == null) {
             log.warn("No 'from' found. Assume min of river.");
             return getRiver().determineMinMaxDistance()[0];
         }
 
-        return from.doubleValue();
+        return this.from.doubleValue();
     }
 
-    /* If left_to_right is set to true this returns
-     * the larger value of from and to. */
-    public double getTo(boolean left_to_right) {
+    /*
+     * If left_to_right is set to true this returns
+     * the larger value of from and to.
+     */
+    public double getTo(final boolean left_to_right) {
         if (!left_to_right) {
             return getTo();
         }
-        double from = getFrom();
-        double to = getTo();
+        final double from = getFrom();
+        final double to = getTo();
         return from > to ? from : to;
     }
 
     /** Return ld_to data (in km), if not found, the max. */
     public double getTo() {
-        if (to == null) {
-            to = getDouble("ld_to");
+        if (this.to == null) {
+            this.to = getDouble("ld_to");
         }
 
         if (log.isDebugEnabled()) {
-            log.debug("to from data: '" + to + "'");
+            log.debug("to from data: '" + this.to + "'");
         }
 
-        if (to == null) {
+        if (this.to == null) {
             log.warn("No 'to' found. Assume max of river.");
             return getRiver().determineMinMaxDistance()[1];
         }
 
-        return to.doubleValue();
+        return this.to.doubleValue();
     }
 
-
     /** Step width for calculation. */
     public Double getStep() {
 
-        if (step == null) {
-            step = getDouble("ld_step");
+        if (this.step == null) {
+            this.step = getDouble("ld_step");
         }
 
         if (log.isDebugEnabled()) {
-            log.debug("step: '" + step + "'");
+            log.debug("step: '" + this.step + "'");
         }
 
-        return step;
+        return this.step;
     }
 
-
     /**
      * Get min and max kilometer, independent of parametization
      * (ld_from/to vs ld_locations).
@@ -213,37 +204,35 @@
     public double[] getKmRange() {
         // TODO store kmRange in field.
         switch (getKmRangeMode()) {
-            case RANGE: {
+        case RANGE: {
+            return getKmFromTo();
+        }
+
+        case LOCATIONS: {
+            final double[] locs = getLocations();
+            // if no locations, nPE.
+            if (locs == null) {
+                log.warn("no locations to get km range from.");
+                return new double[] { Double.NaN, Double.NaN };
+            }
+            return new double[] { locs[0], locs[locs.length - 1] };
+        }
+
+        case NONE: {
+            final double[] locs = getLocations();
+            if (locs != null) {
+                return new double[] { locs[0], locs[locs.length - 1] };
+            } else {
                 return getKmFromTo();
             }
-
-            case LOCATIONS: {
-                double[] locs = getLocations();
-                // if no locations, nPE.
-                if (locs == null) {
-                    log.warn("no locations to get km range from.");
-                    return new double[] { Double.NaN, Double.NaN };
-                }
-                return new double[] { locs[0], locs[locs.length-1] };
-            }
-
-            case NONE: {
-                double[] locs = getLocations();
-                if (locs != null) {
-                    return new double[] { locs[0], locs[locs.length-1] };
-                }
-                else {
-                    return getKmFromTo();
-                }
-            }
+        }
         }
 
         return new double[] { Double.NaN, Double.NaN };
     }
 
-
     public double[] getKmFromTo() {
-         return RiverUtils.getKmFromTo(this.getArtifact());
+        return RiverUtils.getKmFromTo(this.getArtifact());
     }
 
     /**