Small Code Maintenance

jgrapht-core/src/main/java/org/jgrapht/alg/cycle/AhujaOrlinSharmaCyclicExchangeLocalAugmentation.java

@@ -399,8 +399,7 @@ public LabeledPath<V> clone()
 
                 return newLabeledPath;
             } catch (CloneNotSupportedException e) {
-                e.printStackTrace();
-                throw new RuntimeException();
+                throw new RuntimeException(e);
             }
         }
     }

jgrapht-core/src/main/java/org/jgrapht/alg/spanning/AbstractCapacitatedMinimumSpanningTree.java

@@ -430,8 +430,7 @@ public CapacitatedSpanningTreeSolutionRepresentation clone()
 
                 return capacitatedSpanningTreeSolutionRepresentation;
             } catch (CloneNotSupportedException e) {
-                e.printStackTrace();
-                throw new RuntimeException();
+                throw new RuntimeException(e);
             }
         }
     }

jgrapht-core/src/main/java/org/jgrapht/event/TraversalListener.java

@@ -17,6 +17,8 @@
  */
 package org.jgrapht.event;
 
+import java.util.EventListener;
+
 /**
  * A listener on graph iterator or on a graph traverser.
  *
@@ -25,7 +27,7 @@
  *
  * @author Barak Naveh
  */
-public interface TraversalListener<V, E>
+public interface TraversalListener<V, E> extends EventListener
 {
     /**
      * Called to inform listeners that the traversal of the current connected component has

jgrapht-core/src/main/java/org/jgrapht/graph/AbstractBaseGraph.java

@@ -394,8 +394,7 @@ public Object clone()
 
             return newGraph;
         } catch (CloneNotSupportedException e) {
-            e.printStackTrace();
-            throw new RuntimeException();
+            throw new RuntimeException(e);
         }
     }
 

jgrapht-core/src/main/java/org/jgrapht/graph/AbstractGraph.java

@@ -59,6 +59,7 @@ public boolean containsEdge(V sourceVertex, V targetVertex)
     @Override
     public boolean removeAllEdges(Collection<? extends E> edges)
     {
+        Objects.requireNonNull(edges);
         boolean modified = false;
 
         for (E e : edges) {
@@ -90,6 +91,7 @@ public Set<E> removeAllEdges(V sourceVertex, V targetVertex)
     @Override
     public boolean removeAllVertices(Collection<? extends V> vertices)
     {
+        Objects.requireNonNull(vertices);
         boolean modified = false;
 
         for (V v : vertices) {
@@ -124,10 +126,9 @@ public String toString()
      */
     protected boolean assertVertexExist(V v)
     {
+        Objects.requireNonNull(v);
         if (containsVertex(v)) {
             return true;
-        } else if (v == null) {
-            throw new NullPointerException();
         } else {
             throw new IllegalArgumentException("no such vertex in graph: " + v.toString());
         }
@@ -136,7 +137,6 @@ protected boolean assertVertexExist(V v)
     /**
      * Removes all the edges in this graph that are also contained in the specified edge array.
      * After this call returns, this graph will contain no edges in common with the specified edges.
-     * This method will invoke the {@link Graph#removeEdge(Object)} method.
      *
      * @param edges edges to be removed from this graph.
      *
@@ -145,18 +145,12 @@ protected boolean assertVertexExist(V v)
      * @throws NullPointerException if argument is {@code null}
      * @throws UnsupportedOperationException if this graph disallows modification
      *
-     * @see Graph#removeEdge(Object)
-     * @see Graph#containsEdge(Object)
+     * @see #removeAllEdges(Collection)
      */
     protected boolean removeAllEdges(E[] edges)
     {
-        boolean modified = false;
-
-        for (E edge : edges) {
-            modified |= removeEdge(edge);
-        }
-
-        return modified;
+        Objects.requireNonNull(edges);
+        return removeAllEdges(Arrays.asList(edges));
     }
 
     /**

jgrapht-core/src/main/java/org/jgrapht/graph/DefaultListenableGraph.java

@@ -183,8 +183,7 @@ public Object clone()
             return g;
         } catch (CloneNotSupportedException e) {
             // should never get here since we're Cloneable
-            e.printStackTrace();
-            throw new RuntimeException("internal error");
+            throw new Error("internal error", e);
         }
     }
 

jgrapht-core/src/main/java/org/jgrapht/util/ArrayUtil.java

@@ -17,6 +17,8 @@
  */
 package org.jgrapht.util;
 
+import java.util.Objects;
+
 /**
  * Utility class to simplify handling of arrays.
  *
@@ -60,9 +62,7 @@ public static final <V> void reverse(V[] arr, int from, int to)
     public static final void reverse(int[] arr, int from, int to)
     {
         for (int i = from, j = to; i < j; ++i, --j) {
-            int tmp = arr[j];
-            arr[j] = arr[i];
-            arr[i] = tmp;
+            swap(arr, i, j);
         }
     }
 
@@ -79,6 +79,7 @@ public static final void reverse(int[] arr, int from, int to)
      */
     public static final <V> void swap(V[] arr, int i, int j)
     {
+        Objects.requireNonNull(arr);
         V tmp = arr[j];
         arr[j] = arr[i];
         arr[i] = tmp;
@@ -98,6 +99,7 @@ public static final <V> void swap(V[] arr, int i, int j)
      */
     public static void swap(double[] arr, int i, int j)
     {
+        Objects.requireNonNull(arr);
         double tmp = arr[j];
         arr[j] = arr[i];
         arr[i] = tmp;
@@ -117,6 +119,7 @@ public static void swap(double[] arr, int i, int j)
      */
     public static void swap(int[] arr, int i, int j)
     {
+        Objects.requireNonNull(arr);
         int tmp = arr[j];
         arr[j] = arr[i];
         arr[i] = tmp;

jgrapht-core/src/main/java/org/jgrapht/util/WeightCombiner.java

@@ -22,6 +22,7 @@
 /**
  * Binary operator for edge weights. There are some prewritten operators.
  */
+@FunctionalInterface
 public interface WeightCombiner
 {
     /**

jgrapht-core/src/test/java/org/jgrapht/alg/tour/FarthestInsertionHeuristicTSPTest.java

@@ -28,6 +28,7 @@
 import java.util.List;
 
 import static org.jgrapht.alg.tour.TwoApproxMetricTSPTest.assertHamiltonian;
+import static org.junit.jupiter.api.Assertions.*;
 
 /**
  * Unit tests for the {@link FarthestInsertionHeuristicTSP}
@@ -48,7 +49,7 @@ public void testDirectedGraph()
         FarthestInsertionHeuristicTSP<Integer, DefaultWeightedEdge> farthestInsertion =
             new FarthestInsertionHeuristicTSP<>();
 
-        IllegalArgumentException thrown = Assertions.assertThrows(IllegalArgumentException.class, () -> {
+        assertThrows(IllegalArgumentException.class, () -> {
             farthestInsertion.getTour(graph);
         });
 
@@ -64,7 +65,7 @@ public void testEmptyGraph()
             new DefaultUndirectedWeightedGraph<>(DefaultWeightedEdge.class);
         FarthestInsertionHeuristicTSP<Integer, DefaultWeightedEdge> farthestInsertion =
             new FarthestInsertionHeuristicTSP<>();
-        IllegalArgumentException thrown = Assertions.assertThrows(IllegalArgumentException.class, () -> {
+        assertThrows(IllegalArgumentException.class, () -> {
             farthestInsertion.getTour(graph);
         });
     }
@@ -81,7 +82,7 @@ public void testNoCompleteGraph()
         graph.addVertex(1);
         FarthestInsertionHeuristicTSP<Integer, DefaultWeightedEdge> farthestInsertion =
             new FarthestInsertionHeuristicTSP<>();
-        IllegalArgumentException thrown = Assertions.assertThrows(IllegalArgumentException.class, () -> {
+        assertThrows(IllegalArgumentException.class, () -> {
             farthestInsertion.getTour(graph);
         });
     }
@@ -99,7 +100,7 @@ public void testGetTour1()
             new FarthestInsertionHeuristicTSP<>();
         GraphPath<Integer, DefaultEdge> tour = farthestInsertion.getTour(graph);
         assertHamiltonian(graph, tour);
-        Assertions.assertEquals(10, tour.getWeight(), 1e-9);
+        assertEquals(10, tour.getWeight(), 1e-9);
     }
 
     /**
@@ -115,7 +116,7 @@ public void testGetTour2()
             new FarthestInsertionHeuristicTSP<>();
         GraphPath<Integer, DefaultEdge> tour = farthestInsertion.getTour(graph);
         assertHamiltonian(graph, tour);
-        Assertions.assertEquals(19, tour.getWeight(), 1e-9);
+        assertEquals(19, tour.getWeight(), 1e-9);
     }
 
     /**
@@ -134,8 +135,8 @@ public void testDummyGraph5()
         var farthestInsH = new FarthestInsertionHeuristicTSP<Integer, DefaultWeightedEdge>();
 
         var tour = farthestInsH.getTour(graph);
-        Assertions.assertEquals(30, tour.getWeight(), 1e-9);
-        Assertions.assertArrayEquals(new Integer[]{3, 2, 1, 0, 4, 3},
+        assertEquals(30, tour.getWeight(), 1e-9);
+        assertArrayEquals(new Integer[]{3, 2, 1, 0, 4, 3},
             tour.getVertexList().toArray(new Integer[0]));
     }
 
@@ -153,10 +154,10 @@ public void testDummyGraph5WithSubtour()
             <Integer, DefaultWeightedEdge>(new GraphWalk<>(graph, List.of(3, 2, 0, 4), -1));
 
         var tour = farthestInsH.getTour(graph);
-        Assertions.assertEquals(30, tour.getWeight(), 1e-9);
+        assertEquals(30, tour.getWeight(), 1e-9);
 
         // vertex 1 should be inserted between vertices 2 and 0
-        Assertions.assertArrayEquals(new Integer[]{3, 2, 1, 0, 4, 3},
+        assertArrayEquals(new Integer[]{3, 2, 1, 0, 4, 3},
             tour.getVertexList().toArray(new Integer[0]));
     }
 
@@ -180,8 +181,8 @@ public void testDummyGraph10()
         Graph<Integer, DefaultWeightedEdge> graph = createGraphFromMatrixDistances(allDist);
         var farthestInsertion = new FarthestInsertionHeuristicTSP<Integer, DefaultWeightedEdge>();
         var tour = farthestInsertion.getTour(graph);
-        Assertions.assertEquals(210, tour.getWeight(), 1e-9);
-        Assertions.assertArrayEquals(new Integer[]{4, 5, 1, 6, 0, 7, 3, 8, 2, 9, 4},
+        assertEquals(210, tour.getWeight(), 1e-9);
+        assertArrayEquals(new Integer[]{4, 5, 1, 6, 0, 7, 3, 8, 2, 9, 4},
             tour.getVertexList().toArray(new Integer[0]));
     }
 

jgrapht-guava/src/main/java/org/jgrapht/graph/guava/ImmutableGraphAdapter.java

@@ -149,8 +149,7 @@ public Object clone()
 
             return newGraph;
         } catch (CloneNotSupportedException e) {
-            e.printStackTrace();
-            throw new RuntimeException();
+            throw new RuntimeException(e);
         }
     }
 

jgrapht-guava/src/main/java/org/jgrapht/graph/guava/ImmutableNetworkAdapter.java

@@ -155,8 +155,7 @@ public Object clone()
 
             return newGraph;
         } catch (CloneNotSupportedException e) {
-            e.printStackTrace();
-            throw new RuntimeException();
+            throw new RuntimeException(e);
         }
     }
 

jgrapht-guava/src/main/java/org/jgrapht/graph/guava/ImmutableValueGraphAdapter.java

@@ -184,8 +184,7 @@ public Object clone()
 
             return newGraph;
         } catch (CloneNotSupportedException e) {
-            e.printStackTrace();
-            throw new RuntimeException();
+            throw new RuntimeException(e);
         }
     }
 

jgrapht-guava/src/main/java/org/jgrapht/graph/guava/MutableNetworkAdapter.java

@@ -228,8 +228,7 @@ public Object clone()
 
             return newGraph;
         } catch (CloneNotSupportedException e) {
-            e.printStackTrace();
-            throw new RuntimeException();
+            throw new RuntimeException(e);
         }
     }
 

jgrapht-guava/src/main/java/org/jgrapht/graph/guava/MutableValueGraphAdapter.java

@@ -298,8 +298,7 @@ public Object clone()
 
             return newGraph;
         } catch (CloneNotSupportedException e) {
-            e.printStackTrace();
-            throw new RuntimeException();
+            throw new RuntimeException(e);
         }
     }
 

jgrapht-io/src/main/java/org/jgrapht/nio/DefaultAttribute.java

@@ -156,7 +156,6 @@ public int hashCode()
     }
 
     @Override
-    @SuppressWarnings("rawtypes")
     public boolean equals(Object obj)
     {
         if (this == obj)
@@ -165,7 +164,7 @@ public boolean equals(Object obj)
             return false;
         if (getClass() != obj.getClass())
             return false;
-        DefaultAttribute other = (DefaultAttribute) obj;
+        DefaultAttribute<?> other = (DefaultAttribute<?>) obj;
         if (type != other.type)
             return false;
         if (value == null) {