Merging from -r468106:814127 of collections_jdk5_branch - namely where this code was generified; mostly in r738956.

Also see the following revisions:

    ------------------------------------------------------------------------
    r593347 | skestle | 2007-11-08 14:49:02 -0800 (Thu, 08 Nov 2007) | 3 lines
    
    Added initial IndexedCollection - still needs quite a bit of work - see TODO comments
    
    JIRA: COLLECTIONS-275
    ------------------------------------------------------------------------


git-svn-id: https://svn.apache.org/repos/asf/commons/proper/collections/trunk@815149 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -0,0 +1,73 @@
+package org.apache.commons.collections;
+
+import static java.util.Arrays.asList;
+import static junit.framework.Assert.assertEquals;
+import static junit.framework.Assert.assertNull;
+
+import org.junit.Before;
+import org.junit.Test;
+
+public class TestIndexedCollection extends AbstractDecoratedCollectionTest<String> {
+    private IndexedCollection<Integer, String> indexed;
+
+    @Before
+    public void setUp() throws Exception {
+        indexed = IndexedCollection.uniqueIndexedCollection(original, new Transformer<String, Integer>() {
+            public Integer transform(String input) {
+                return Integer.parseInt(input);
+            }
+        });
+        decorated = indexed;
+    }
+    
+    @Test
+    public void addedObjectsCanBeRetrievedByKey() throws Exception {
+        decorated.add("12");
+        decorated.add("16");
+        decorated.add("1");
+        decorated.addAll(asList("2","3","4"));
+        assertEquals("12", indexed.get(12));
+        assertEquals("16", indexed.get(16));
+        assertEquals("1", indexed.get(1));
+        assertEquals("2", indexed.get(2));
+        assertEquals("3", indexed.get(3));
+        assertEquals("4", indexed.get(4));
+    }
+    
+    @Test(expected=IllegalArgumentException.class)
+    public void ensureDuplicateObjectsCauseException() throws Exception {
+        decorated.add("1");
+        decorated.add("1");
+    }
+    
+    @Test
+    public void decoratedCollectionIsIndexedOnCreation() throws Exception {
+        original.add("1");
+        original.add("2");
+        original.add("3");
+        
+        indexed = IndexedCollection.uniqueIndexedCollection(original, new Transformer<String, Integer>() {
+            public Integer transform(String input) {
+                return Integer.parseInt(input);
+            }
+        });
+        assertEquals("1", indexed.get(1));
+        assertEquals("2", indexed.get(2));
+        assertEquals("3", indexed.get(3));
+    }
+    
+    @Test
+    public void reindexUpdatesIndexWhenTheDecoratedCollectionIsModifiedSeparately() throws Exception {
+        original.add("1");
+        original.add("2");
+        original.add("3");
+        
+        assertNull(indexed.get(1));
+        assertNull(indexed.get(2));
+        assertNull(indexed.get(3));
+        indexed.reindex();
+        assertEquals("1", indexed.get(1));
+        assertEquals("2", indexed.get(2));
+        assertEquals("3", indexed.get(3));
+    }
+}