svn commit: r1290996 - /commons/sandbox/graph/trunk/src/main/java/org/apache/commons/graph/spanning/DefaultSpanningTreeAlgorithmSelector.java

[marcosperanza]

Author: marcosperanza
Date: Sun Feb 19 13:21:23 2012
New Revision: 1290996

URL: http://svn.apache.org/viewvc?rev=1290996&view=rev
Log:
Added check for monoid input argument 

Modified:
    
commons/sandbox/graph/trunk/src/main/java/org/apache/commons/graph/spanning/DefaultSpanningTreeAlgorithmSelector.java

Modified: 
commons/sandbox/graph/trunk/src/main/java/org/apache/commons/graph/spanning/DefaultSpanningTreeAlgorithmSelector.java
URL: 
http://svn.apache.org/viewvc/commons/sandbox/graph/trunk/src/main/java/org/apache/commons/graph/spanning/DefaultSpanningTreeAlgorithmSelector.java?rev=1290996&r1=1290995&r2=1290996&view=diff
==============================================================================
--- 
commons/sandbox/graph/trunk/src/main/java/org/apache/commons/graph/spanning/DefaultSpanningTreeAlgorithmSelector.java
 (original)
+++ 
commons/sandbox/graph/trunk/src/main/java/org/apache/commons/graph/spanning/DefaultSpanningTreeAlgorithmSelector.java
 Sun Feb 19 13:21:23 2012
@@ -20,6 +20,8 @@ package org.apache.commons.graph.spannin
  */
 
 import static org.apache.commons.graph.utils.Assertions.checkState;
+import static org.apache.commons.graph.utils.Assertions.checkNotNull;
+
 
 import java.util.HashMap;
 import java.util.HashSet;
@@ -77,7 +79,7 @@ final class DefaultSpanningTreeAlgorithm
          *     end while
          * <pre>
          */
-
+        checkNotNull( orderedMonoid, "The Boruvka algorithm can't be calulated 
with a null monoid" );
         final MutableSpanningTree<V, WE, W> spanningTree =
             new MutableSpanningTree<V, WE, W>( orderedMonoid );
 
@@ -157,6 +159,8 @@ final class DefaultSpanningTreeAlgorithm
      */
     public <OM extends OrderedMonoid<W>> SpanningTree<V, WE, W> 
applyingKruskalAlgorithm( OM orderedMonoid )
     {
+        
+        checkNotNull( orderedMonoid, "The Kruskal algorithm can't be calulated 
with a null monoid" );
         final Set<V> settledNodes = new HashSet<V>();
 
         final PriorityQueue<WE> orderedEdges =
@@ -202,6 +206,8 @@ final class DefaultSpanningTreeAlgorithm
      */
     public <OM extends OrderedMonoid<W>> SpanningTree<V, WE, W> 
applyingPrimAlgorithm( OM orderedMonoid )
     {
+        checkNotNull( orderedMonoid, "The Prim algorithm can't be calulated 
with a null monoid" );
+        
         final ShortestEdges<V, WE, W> shortestEdges = new ShortestEdges<V, WE, 
W>( graph, source, orderedMonoid );
 
         final PriorityQueue<V> unsettledNodes = new PriorityQueue<V>( 
graph.getOrder(), shortestEdges );