Added TypedCollectionsUtilities class.

Tym the Enchanter · Tym the Enchanter · commit 1e4794b45b1d · 2010-06-05T16:38:28.000+01:00
This provides a means of getting collections of one type from collections of another.

E.g. getting all the elements that are instances of java.lang.Double from a collection of java.lang.Number
diff --git a/RandomCodingJavaUtilities/src/uk/co/randomcoding/java/util/collection/TypedCollectionUtilities.java b/RandomCodingJavaUtilities/src/uk/co/randomcoding/java/util/collection/TypedCollectionUtilities.java
@@ -0,0 +1,47 @@
+/*
+ * (c) Tym The Enchanter (tymtheenchanter@randomcoding.co.uk), 5 Jun 2010
+ */
+package uk.co.randomcoding.java.util.collection;
+
+import java.util.Collection;
+import java.util.HashSet;
+
+/**
+ * <p>
+ * Class to provide operations for typed collections.
+ * </p>
+ * Created on: 5 Jun 2010<br>
+ * 
+ * @author Tym the Enchanter <tymtheenchanter@randomcoding.co.uk>
+ */
+public class TypedCollectionUtilities
+{
+	/**
+	 * Creates a new collection of the elements in the source collection that are also of the target collection type
+	 * <p>
+	 * Added by: Tym the Enchanter <tymtheenchanter@randomcoding.co.uk><br>
+	 * On: 5 Jun 2010<br>
+	 * </p>
+	 * 
+	 * @param <T> The type of the returned collection
+	 * @param sourceCollection The source collection to get the elements from
+	 * @param targetCollectionType The type of the returned collection
+	 * @return A collection of the specified type, containing those elements from the source collection that are of the
+	 *         required type
+	 */
+	@SuppressWarnings("unchecked")
+	public static <T> Collection<T> extractTypedCollection(Collection<?> sourceCollection, Class<T> targetCollectionType)
+	{
+		Collection<T> typedCollection = new HashSet<T>();
+
+		for (Object sourceObject : sourceCollection)
+		{
+			if (targetCollectionType.isAssignableFrom(sourceObject.getClass()))
+			{
+				typedCollection.add((T) sourceObject);
+			}
+		}
+
+		return typedCollection;
+	}
+}
