CollectionUtils.addIgnoreNull new method

bug 30020, from Rafael U. C. Afonso


git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/proper/collections/trunk@131811 13f79535-47bb-0310-9956-ffa450edef68

RELEASE-NOTES.html

@@ -34,12 +34,12 @@ The only new deprecations are ................
 
 <center><h3>NEW CLASSES</h3></center>
 <ul>
-<li>LoopingListIterator - When the end of the list is reached the iteration continues from the start</li>
+<li>LoopingListIterator - When the end of the list is reached the iteration continues from the start [30166]</li>
 </ul>
 
 <center><h3>ENHANCEMENTS</h3></center>
 <ul>
-<li>........</li>
+<li>CollectionUtils.addIgnoreNull - Adds to the collection if the value being added is not null [30020]</li>
 </ul>
 
 <center><h3>BUG FIXES</h3></center>
@@ -49,5 +49,5 @@ The only new deprecations are ................
 
 <center><h3>JAVADOC</h3></center>
 <ul>
-<li>........</li>
+<li>MapUtils.safeAddToMap - Better comment</li>
 </ul>

src/java/org/apache/commons/collections/CollectionUtils.java

@@ -38,7 +38,7 @@ import org.apache.commons.collections.collection.UnmodifiableCollection;
  * Provides utility methods and decorators for {@link Collection} instances.
  *
  * @since Commons Collections 1.0
- * @version $Revision: 1.61 $ $Date: 2004/04/27 20:00:18 $
+ * @version $Revision: 1.62 $ $Date: 2004/07/17 21:38:33 $
  * 
  * @author Rodney Waldhoff
  * @author Paul Jack
@@ -633,11 +633,24 @@ public class CollectionUtils {
         return outputCollection;
     }
 
+    //-----------------------------------------------------------------------
+    /**
+     * 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
+     * @throws NullPointerException if the collection is null
+     */
+    public static boolean addIgnoreNull(Collection collection, Object object) {
+        return (object == null ? false : collection.add(object));
+    }
+    
     /**
      * Adds all elements in the iteration to the given collection.
      * 
-     * @param collection  the collection to add to
+     * @param collection  the collection to add to, must not be null
-     * @param iterator  the iterator of elements to add, may not be null
+     * @param iterator  the iterator of elements to add, must not be null
      * @throws NullPointerException if the collection or iterator is null
      */
     public static void addAll(Collection collection, Iterator iterator) {
@@ -649,8 +662,8 @@ public class CollectionUtils {
     /**
      * Adds all elements in the enumeration to the given collection.
      * 
-     * @param collection  the collection to add to
+     * @param collection  the collection to add to, must not be null
-     * @param enumeration  the enumeration of elements to add, may not be null
+     * @param enumeration  the enumeration of elements to add, must not be null
      * @throws NullPointerException if the collection or enumeration is null
      */
     public static void addAll(Collection collection, Enumeration enumeration) {
@@ -662,8 +675,8 @@ public class CollectionUtils {
     /** 
      * Adds all elements in the array to the given collection.
      * 
-     * @param collection  the collection to add to, may not be null
+     * @param collection  the collection to add to, must not be null
-     * @param elements  the array of elements to add, may not be null
+     * @param elements  the array of elements to add, must not be null
      * @throws NullPointerException if the collection or array is null
      */
     public static void addAll(Collection collection, Object[] elements) {

src/test/org/apache/commons/collections/TestCollectionUtils.java

@@ -50,7 +50,7 @@ import org.apache.commons.collections.collection.UnmodifiableCollection;
  * @author Phil Steitz
  * @author Steven Melzer
  * 
- * @version $Revision: 1.39 $ $Date: 2004/06/26 10:00:42 $
+ * @version $Revision: 1.40 $ $Date: 2004/07/17 21:38:33 $
  */
 public class TestCollectionUtils extends TestCase {
     
@@ -965,6 +965,22 @@ public class TestCollectionUtils extends TestCase {
         assertEquals(new Integer(4), set.iterator().next());
     }
 
+    //-----------------------------------------------------------------------
+    public void testAddIgnoreNull() {
+        Set set = new HashSet();
+        set.add("1");
+        set.add("2");
+        set.add("3");
+        assertEquals(false, CollectionUtils.addIgnoreNull(set, null));
+        assertEquals(3, set.size());
+        assertEquals(false, CollectionUtils.addIgnoreNull(set, "1"));
+        assertEquals(3, set.size());
+        assertEquals(true, CollectionUtils.addIgnoreNull(set, "4"));
+        assertEquals(4, set.size());
+        assertEquals(true, set.contains("4"));
+    }
+
+    //-----------------------------------------------------------------------
     public void testPredicatedCollection() {
         Predicate predicate = new Predicate() {
             public boolean evaluate(Object o) {