[COLLECTIONS-182] return Closure from CollectionUtils.forAllDo git-svn-id: https://svn.apache.org/repos/asf/commons/proper/collections/branches/collections_jdk5_branch@813925 13f79535-47bb-0310-9956-ffa450edef68
Project: http://git-wip-us.apache.org/repos/asf/commons-collections/repo Commit: http://git-wip-us.apache.org/repos/asf/commons-collections/commit/dabd2401 Tree: http://git-wip-us.apache.org/repos/asf/commons-collections/tree/dabd2401 Diff: http://git-wip-us.apache.org/repos/asf/commons-collections/diff/dabd2401 Branch: refs/heads/collections_jdk5_branch Commit: dabd2401bd294bf33ffef9fbc10dd732a4ac4bf2 Parents: df940e0 Author: Matthew Jason Benson <mben...@apache.org> Authored: Fri Sep 11 17:05:31 2009 +0000 Committer: Matthew Jason Benson <mben...@apache.org> Committed: Fri Sep 11 17:05:31 2009 +0000 ---------------------------------------------------------------------- .../commons/collections/CollectionUtils.java | 150 ++++++++++--------- .../collections/TestCollectionUtils.java | 23 +-- 2 files changed, 89 insertions(+), 84 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/commons-collections/blob/dabd2401/src/java/org/apache/commons/collections/CollectionUtils.java ---------------------------------------------------------------------- diff --git a/src/java/org/apache/commons/collections/CollectionUtils.java b/src/java/org/apache/commons/collections/CollectionUtils.java index 1208eb4..cf34edc 100644 --- a/src/java/org/apache/commons/collections/CollectionUtils.java +++ b/src/java/org/apache/commons/collections/CollectionUtils.java @@ -5,9 +5,9 @@ * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at - * + * * http://www.apache.org/licenses/LICENSE-2.0 - * + * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. @@ -37,10 +37,10 @@ import org.apache.commons.collections.collection.UnmodifiableCollection; /** * Provides utility methods and decorators for {@link Collection} instances. * Method parameters will take {@link Iterable} objects when possible. - * + * * @since Commons Collections 1.0 * @version $Revision$ $Date$ - * + * * @author Rodney Waldhoff * @author Paul Jack * @author Stephen Colebourne @@ -62,16 +62,16 @@ public class CollectionUtils { private static class CardinalityHelper<O> { final Map<O, Integer> cardinalityA, cardinalityB; - + public CardinalityHelper(Iterable<? extends O> a, Iterable<? extends O> b) { cardinalityA = CollectionUtils.<O>getCardinalityMap(a); cardinalityB = CollectionUtils.<O>getCardinalityMap(b); } - + public final int max(Object obj) { return Math.max(freqA(obj), freqB(obj)); } - + public final int min(Object obj) { return Math.min(freqA(obj), freqB(obj)); } @@ -79,11 +79,11 @@ public class CollectionUtils { public int freqA(Object obj) { return getFreq(obj, cardinalityA); } - + public int freqB(Object obj) { return getFreq(obj, cardinalityB); } - + private final int getFreq(final Object obj, final Map<?, Integer> freqMap) { Integer count = freqMap.get(obj); if (count != null) { @@ -92,7 +92,7 @@ public class CollectionUtils { return 0; } } - + private static class SetOperationCardinalityHelper<O> extends CardinalityHelper<O> implements Iterable<O> { private final Set<O> elements; private final List<O> newList; @@ -138,7 +138,7 @@ public class CollectionUtils { /** * Returns the immutable EMPTY_COLLECTION with generic type safety. - * + * * @see #EMPTY_COLLECTION * @since 4.0 * @return immutable empty collection @@ -155,7 +155,7 @@ public class CollectionUtils { * The cardinality of each element in the returned {@link Collection} will * be equal to the maximum of the cardinality of that element in the two * given {@link Collection}s. - * + * * @param a the first collection, must not be null * @param b the second collection, must not be null * @param <O> the generic type that is able to represent the types contained @@ -178,7 +178,7 @@ public class CollectionUtils { * The cardinality of each element in the returned {@link Collection} will * be equal to the minimum of the cardinality of that element in the two * given {@link Collection}s. - * + * * @param a the first collection, must not be null * @param b the second collection, must not be null * @param <O> the generic type that is able to represent the types contained @@ -207,7 +207,7 @@ public class CollectionUtils { * <tt>{@link #subtract subtract}({@link #union union(a,b)},{@link #intersection intersection(a,b)})</tt> * or * <tt>{@link #union union}({@link #subtract subtract(a,b)},{@link #subtract subtract(b,a)})</tt>. - + * @param a the first collection, must not be null * @param b the second collection, must not be null * @param <O> the generic type that is able to represent the types contained @@ -280,7 +280,7 @@ public class CollectionUtils { * <p> * Only those elements present in the collection will appear as * keys in the map. - * + * * @param coll * the collection to get the cardinality map for, must not be * null @@ -309,7 +309,7 @@ public class CollectionUtils { * that is, iff the cardinality of <i>e</i> in <i>a</i> is less than or * equal to the cardinality of <i>e</i> in <i>b</i>, for each element <i>e</i> * in <i>a</i>. - * + * * @param a the first (sub?) collection, must not be null * @param b the second (super?) collection, must not be null * @return <code>true</code> iff <i>a</i> is a sub-collection of <i>b</i> @@ -336,7 +336,7 @@ public class CollectionUtils { * <p> * The implementation assumes * <ul> - * <li><code>a.size()</code> and <code>b.size()</code> represent the + * <li><code>a.size()</code> and <code>b.size()</code> represent the * total cardinality of <i>a</i> and <i>b</i>, resp. </li> * <li><code>a.size() < Integer.MAXVALUE</code></li> * </ul> @@ -381,7 +381,7 @@ public class CollectionUtils { /** * Returns the number of occurrences of <i>obj</i> in <i>coll</i>. - * + * * @param obj the object to find the cardinality of * @param coll the {@link Iterable} to search * @param <O> the type of object that the {@link Iterable} may contain. @@ -411,10 +411,10 @@ public class CollectionUtils { return count; } - /** + /** * Finds the first element in the given collection which matches the given predicate. * <p> - * If the input collection or predicate is null, or no element of the collection + * If the input collection or predicate is null, or no element of the collection * matches the predicate, null is returned. * * @param collection the collection to search, may be null @@ -436,18 +436,20 @@ public class CollectionUtils { * Executes the given closure on each element in the collection. * <p> * If the input collection or closure is null, there is no change made. - * + * * @param collection * the collection to get the input from, may be null * @param closure * the closure to perform, may be null + * @return closure */ - public static <T> void forAllDo(Collection<T> collection, Closure<? super T> closure) { + public static <T, C extends Closure<? super T>> C forAllDo(Collection<T> collection, C closure) { if (collection != null && closure != null) { for (T element : collection) { closure.execute(element); } } + return closure; } /** @@ -455,7 +457,7 @@ public class CollectionUtils { * predicate returns false, remove the element. * <p> * If the input collection or predicate is null, there is no change made. - * + * * @param collection * the collection to get the input from, may be null * @param predicate @@ -483,7 +485,7 @@ public class CollectionUtils { * If the input collection controls its input, such as a Set, and the * Transformer creates duplicates (or are otherwise invalid), the collection * may reduce in size due to calling this method. - * + * * @param collection * the {@link Iterable} to get the input from, may be null * @param transformer @@ -510,7 +512,7 @@ public class CollectionUtils { * predicate. * <p> * A <code>null</code> collection or predicate matches no elements. - * + * * @param input * the {@link Iterable} to get the input from, may be null * @param predicate @@ -534,7 +536,7 @@ public class CollectionUtils { * collection. * <p> * A <code>null</code> collection or predicate returns false. - * + * * @param input * the {@link Iterable} to get the input from, may be null * @param predicate @@ -558,7 +560,7 @@ public class CollectionUtils { * predicate into an output collection. * <p> * A <code>null</code> predicate matches no elements. - * + * * @param inputCollection * the collection to get the input from, may not be null * @param predicate @@ -578,7 +580,7 @@ public class CollectionUtils { * <p> * If the input collection or predicate is null, there is no change to the * output collection. - * + * * @param inputCollection * the collection to get the input from, may be null * @param predicate @@ -605,7 +607,7 @@ public class CollectionUtils { * <p> * If the input predicate is <code>null</code>, the result is an empty * list. - * + * * @param inputCollection * the collection to get the input from, may not be null * @param predicate @@ -625,7 +627,7 @@ public class CollectionUtils { * <p> * If the input predicate is <code>null</code>, no elements are added to * <code>outputCollection</code>. - * + * * @param inputCollection * the collection to get the input from, may be null * @param predicate @@ -651,7 +653,7 @@ public class CollectionUtils { * transformed by the given transformer. * <p> * If the input transformer is null, the result is an empty list. - * + * * @param inputCollection * the collection to get the input from, may not be null * @param transformer @@ -675,7 +677,7 @@ public class CollectionUtils { * <p> * If the input iterator or transformer is null, the result is an empty * list. - * + * * @param inputIterator * the iterator to get the input from, may be null * @param transformer @@ -690,12 +692,12 @@ public class CollectionUtils { collect(inputIterator, transformer, answer); return answer; } - - /** - * Transforms all elements from inputCollection with the given transformer + + /** + * Transforms all elements from inputCollection with the given transformer * and adds them to the outputCollection. * <p> - * If the input collection or transformer is null, there is no change to the + * If the input collection or transformer is null, there is no change to the * output collection. * * @param inputCollection the collection to get the input from, may be null @@ -715,11 +717,11 @@ public class CollectionUtils { return outputCollection; } - /** - * Transforms all elements from the inputIterator with the given transformer + /** + * Transforms all elements from the inputIterator with the given transformer * and adds them to the outputCollection. * <p> - * If the input iterator or transformer is null, there is no change to the + * If the input iterator or transformer is null, there is no change to the * output collection. * * @param inputIterator the iterator to get the input from, may be null @@ -747,7 +749,7 @@ public class CollectionUtils { //----------------------------------------------------------------------- /** * Adds an element to the collection unless the element is null. - * + * * @param collection the collection to add to, must not be null * @param object the object to add, if null it will not be added * @return true if the collection changed @@ -762,7 +764,7 @@ public class CollectionUtils { * Adds all elements in the {@link Iterable} to the given collection. If the * {@link Iterable} is a {@link Collection} then it is cast and will be * added using {@link Collection#addAll(Collection)} instead of iterating. - * + * * @param collection * the collection to add to, must not be null * @param iterable @@ -780,7 +782,7 @@ public class CollectionUtils { /** * Adds all elements in the iteration to the given collection. - * + * * @param collection * the collection to add to, must not be null * @param iterator @@ -799,7 +801,7 @@ public class CollectionUtils { /** * Adds all elements in the enumeration to the given collection. - * + * * @param collection the collection to add to, must not be null * @param enumeration the enumeration of elements to add, must not be null * @throws NullPointerException if the collection or enumeration is null @@ -813,7 +815,7 @@ public class CollectionUtils { /** * Adds all elements in the array to the given collection. - * + * * @param collection * the collection to add to, must not be null * @param elements @@ -830,10 +832,10 @@ public class CollectionUtils { /** * Returns the <code>index</code>-th value in {@link Iterator}, throwing * <code>IndexOutOfBoundsException</code> if there is no such element. - * The Iterator is advanced to - * <code>index</code> (or to the end, if <code>index</code> exceeds the + * The Iterator is advanced to + * <code>index</code> (or to the end, if <code>index</code> exceeds the * number of entries) as a side effect of this method.</li> - * + * * @param iterator the iterator to get a value from * @param index the index to get * @param <T> the type of object in the {@link Iterator} @@ -864,13 +866,13 @@ public class CollectionUtils { throw new IndexOutOfBoundsException("Index cannot be negative: " + index); } } - + /** * Returns the <code>index</code>-th value in the <code>iterable</code>'s {@link Iterator}, throwing * <code>IndexOutOfBoundsException</code> if there is no such element. * <p> * If the {@link Iterable} is a {@link List}, then it will use {@link List#get(int)}. - * + * * @param iterable the {@link Iterable} to get a value from * @param index the index to get * @param <T> the type of object in the {@link Iterable}. @@ -884,31 +886,31 @@ public class CollectionUtils { } return get(iterable.iterator(), index); } - + /** * Returns the <code>index</code>-th value in <code>object</code>, throwing - * <code>IndexOutOfBoundsException</code> if there is no such element or - * <code>IllegalArgumentException</code> if <code>object</code> is not an + * <code>IndexOutOfBoundsException</code> if there is no such element or + * <code>IllegalArgumentException</code> if <code>object</code> is not an * instance of one of the supported types. * <p> * The supported types, and associated semantics are: * <ul> - * <li> Map -- the value returned is the <code>Map.Entry</code> in position - * <code>index</code> in the map's <code>entrySet</code> iterator, + * <li> Map -- the value returned is the <code>Map.Entry</code> in position + * <code>index</code> in the map's <code>entrySet</code> iterator, * if there is such an entry.</li> * <li> List -- this method is equivalent to the list's get method.</li> - * <li> Array -- the <code>index</code>-th array entry is returned, + * <li> Array -- the <code>index</code>-th array entry is returned, * if there is such an entry; otherwise an <code>IndexOutOfBoundsException</code> * is thrown.</li> - * <li> Collection -- the value returned is the <code>index</code>-th object + * <li> Collection -- the value returned is the <code>index</code>-th object * returned by the collection's default iterator, if there is such an element.</li> * <li> Iterator or Enumeration -- the value returned is the * <code>index</code>-th object in the Iterator/Enumeration, if there - * is such an element. The Iterator/Enumeration is advanced to - * <code>index</code> (or to the end, if <code>index</code> exceeds the + * is such an element. The Iterator/Enumeration is advanced to + * <code>index</code> (or to the end, if <code>index</code> exceeds the * number of entries) as a side effect of this method.</li> * </ul> - * + * * @param object the object to get a value from * @param index the index to get * @return the object at the specified index @@ -964,7 +966,7 @@ public class CollectionUtils { /** * Returns the <code>index</code>-th <code>Map.Entry</code> in the <code>map</code>'s <code>entrySet</code>, throwing * <code>IndexOutOfBoundsException</code> if there is no such element. - * + * * @param map the object to get a value from * @param index the index to get * @return the object at the specified index @@ -974,8 +976,8 @@ public class CollectionUtils { checkIndexBounds(index); return get(map.entrySet(), index); } - - /** + + /** * Gets the size of the collection/iterator specified. * <p> * This method can handles objects as follows @@ -986,7 +988,7 @@ public class CollectionUtils { * <li>Iterator - the number of elements remaining in the iterator * <li>Enumeration - the number of elements remaining in the enumeration * </ul> - * + * * @param object the object to get the size of * @return the size of the specified collection * @throws IllegalArgumentException thrown if object is not recognised or null @@ -1038,7 +1040,7 @@ public class CollectionUtils { * <p> * Note: This method is named to avoid clashing with * {@link #isEmpty(Collection)}. - * + * * @param object the object to get the size of, not null * @return true if empty * @throws IllegalArgumentException thrown if object is not recognised or null @@ -1071,7 +1073,7 @@ public class CollectionUtils { * Null-safe check if the specified collection is empty. * <p> * Null returns true. - * + * * @param coll the collection to check, may be null * @return true if empty or null * @since Commons Collections 3.2 @@ -1084,7 +1086,7 @@ public class CollectionUtils { * Null-safe check if the specified collection is not empty. * <p> * Null returns false. - * + * * @param coll the collection to check, may be null * @return true if non-null and non-empty * @since Commons Collections 3.2 @@ -1096,7 +1098,7 @@ public class CollectionUtils { //----------------------------------------------------------------------- /** * Reverses the order of the given array. - * + * * @param array the array to reverse */ public static void reverseArray(Object[] array) { @@ -1183,7 +1185,7 @@ public class CollectionUtils { * in <code>collection</code> unless <code>retain</code> does not contain <code>e</code>, in which * case the cardinality is zero. This method is useful if you do not wish to modify * the collection <code>c</code> and thus cannot call <code>c.retainAll(retain);</code>. - * + * * @param collection the collection whose contents are the target of the #retailAll operation * @param retain the collection containing the elements to be retained in the returned collection * @return a <code>Collection</code> containing all the elements of <code>collection</code> @@ -1203,7 +1205,7 @@ public class CollectionUtils { * in <code>collection</code> unless <code>remove</code> contains <code>e</code>, in which * case the cardinality is zero. This method is useful if you do not wish to modify * the collection <code>c</code> and thus cannot call <code>collection.removeAll(remove);</code>. - * + * * @param collection the collection from which items are removed (in the returned collection) * @param remove the items to be removed from the returned <code>collection</code> * @return a <code>Collection</code> containing all the elements of <code>collection</code> except @@ -1219,9 +1221,9 @@ public class CollectionUtils { /** * Returns a synchronized collection backed by the given collection. * <p> - * You must manually synchronize on the returned buffer's iterator to + * You must manually synchronize on the returned buffer's iterator to * avoid non-deterministic behavior: - * + * * <pre> * Collection c = CollectionUtils.synchronizedCollection(myCollection); * synchronized (c) { @@ -1231,9 +1233,9 @@ public class CollectionUtils { * } * } * </pre> - * + * * This method uses the implementation in the decorators subpackage. - * + * * @param collection the collection to synchronize, must not be null * @return a synchronized collection backed by the given collection * @throws IllegalArgumentException if the collection is null @@ -1277,7 +1279,7 @@ public class CollectionUtils { * Returns a transformed bag backed by the given collection. * <p> * Each object is passed through the transformer as it is added to the - * Collection. It is important not to use the original collection after invoking this + * Collection. It is important not to use the original collection after invoking this * method, as it is a backdoor for adding untransformed objects. * * @param collection the collection to predicate, must not be null http://git-wip-us.apache.org/repos/asf/commons-collections/blob/dabd2401/src/test/org/apache/commons/collections/TestCollectionUtils.java ---------------------------------------------------------------------- diff --git a/src/test/org/apache/commons/collections/TestCollectionUtils.java b/src/test/org/apache/commons/collections/TestCollectionUtils.java index 02732fc..7b613e6 100644 --- a/src/test/org/apache/commons/collections/TestCollectionUtils.java +++ b/src/test/org/apache/commons/collections/TestCollectionUtils.java @@ -5,9 +5,9 @@ * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at - * + * * http://www.apache.org/licenses/LICENSE-2.0 - * + * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. @@ -21,6 +21,7 @@ import static org.apache.commons.collections.functors.EqualPredicate.equalPredic import static org.junit.Assert.assertEquals; import static org.junit.Assert.assertNull; import static org.junit.Assert.assertTrue; +import static org.junit.Assert.assertSame; import static org.junit.Assert.fail; import java.util.*; @@ -36,7 +37,7 @@ import org.junit.Test; /** * Tests for CollectionUtils. - * + * * @author Rodney Waldhoff * @author Matthew Hawthorne * @author Stephen Colebourne @@ -503,11 +504,13 @@ public class TestCollectionUtils extends MockTestCase { Collection<List<? extends Number>> col = new ArrayList<List<? extends Number>>(); col.add(collectionA); col.add(collectionB); - CollectionUtils.forAllDo(col, testClosure); + Closure<List<? extends Number>> resultClosure = CollectionUtils.forAllDo(col, testClosure); + assertSame(testClosure, resultClosure); assertTrue(collectionA.isEmpty() && collectionB.isEmpty()); - CollectionUtils.forAllDo(col, null); + resultClosure = CollectionUtils.forAllDo(col, null); + assertNull(resultClosure); assertTrue(collectionA.isEmpty() && collectionB.isEmpty()); - CollectionUtils.forAllDo(null, testClosure); + resultClosure = CollectionUtils.forAllDo(null, testClosure); col.add(null); // null should be OK CollectionUtils.forAllDo(col, testClosure); @@ -642,7 +645,7 @@ public class TestCollectionUtils extends MockTestCase { // ArrayIndexOutOfBoundsException CollectionUtils.get(objArray, 2); } - + @Test(expected = IndexOutOfBoundsException.class) public void getFromPrimativeArray() throws Exception { // Primitive array, entry exists @@ -884,7 +887,7 @@ public class TestCollectionUtils extends MockTestCase { assertEquals(1, (int) ints.size()); assertEquals(2, (int) ints.get(0)); } - + @Test public void filterNullParameters() throws Exception { List<Long> longs = Collections.nCopies(4, 10L); @@ -962,7 +965,7 @@ public class TestCollectionUtils extends MockTestCase { Collection<Number> collection = CollectionUtils.<Integer, Number>collect(iterableA, transformer); assertTrue(collection.size() == collectionA.size()); assertCollectResult(collection); - + ArrayList<Number> list; list = CollectionUtils.collect(collectionA, transformer, new ArrayList<Number>()); assertTrue(list.size() == collectionA.size()); @@ -1144,7 +1147,7 @@ public class TestCollectionUtils extends MockTestCase { // Let elta and eltb be objects... Integer elta = new Integer(17); Integer eltb = new Integer(17); - + // ...which are equal... assertEquals(elta, eltb); assertEquals(eltb, elta);
