scolebourne 2004/03/31 13:43:27
Modified: collections RELEASE-NOTES.html project.xml
collections/src/test/org/apache/commons/collections
TestCollectionUtils.java
collections/src/java/org/apache/commons/collections
CollectionUtils.java
Log:
Add size(Object) method to find the size of various collection-like objects
bug 27909, from Steven Melzer
Revision Changes Path
1.18 +1 -0 jakarta-commons/collections/RELEASE-NOTES.html
Index: RELEASE-NOTES.html
===================================================================
RCS file: /home/cvs/jakarta-commons/collections/RELEASE-NOTES.html,v
retrieving revision 1.17
retrieving revision 1.18
diff -u -r1.17 -r1.18
--- RELEASE-NOTES.html 17 Mar 2004 21:14:10 -0000 1.17
+++ RELEASE-NOTES.html 31 Mar 2004 21:43:27 -0000 1.18
@@ -34,6 +34,7 @@
<li>AbstractHashedMap,AbstractLinkedMap - Add methods to access entry methods when
protected scope blocks</li>
<li>Functors - Add get methods to retrieve internal state [27515]</li>
<li>MultiHashMap - Add five methods to improve the API</li>
+<li>CollectionUtils - Add size(Object) method to find the size of various
collection-like objects [27909]</li>
</ul>
<center><h3>BUG FIXES</h3></center>
1.35 +3 -0 jakarta-commons/collections/project.xml
Index: project.xml
===================================================================
RCS file: /home/cvs/jakarta-commons/collections/project.xml,v
retrieving revision 1.34
retrieving revision 1.35
diff -u -r1.34 -r1.35
--- project.xml 13 Mar 2004 16:34:46 -0000 1.34
+++ project.xml 31 Mar 2004 21:43:27 -0000 1.35
@@ -175,6 +175,9 @@
<name>Brian McCallister</name>
</contributor>
<contributor>
+ <name>Steven Melzer</name>
+ </contributor>
+ <contributor>
<name>Leon Messerschmidt</name>
</contributor>
<contributor>
1.36 +61 -2
jakarta-commons/collections/src/test/org/apache/commons/collections/TestCollectionUtils.java
Index: TestCollectionUtils.java
===================================================================
RCS file:
/home/cvs/jakarta-commons/collections/src/test/org/apache/commons/collections/TestCollectionUtils.java,v
retrieving revision 1.35
retrieving revision 1.36
diff -u -r1.35 -r1.36
--- TestCollectionUtils.java 18 Feb 2004 01:20:35 -0000 1.35
+++ TestCollectionUtils.java 31 Mar 2004 21:43:27 -0000 1.36
@@ -46,6 +46,7 @@
* @author Matthew Hawthorne
* @author Stephen Colebourne
* @author Phil Steitz
+ * @author Steven Melzer
*
* @version $Revision$ $Date$
*/
@@ -686,7 +687,65 @@
}
}
-
+ public void testSize_List() {
+ List list = new ArrayList();
+ assertEquals(0, CollectionUtils.size(list));
+ list.add("a");
+ assertEquals(1, CollectionUtils.size(list));
+ list.add("b");
+ assertEquals(2, CollectionUtils.size(list));
+ }
+ public void testSize_Map() {
+ Map map = new HashMap();
+ assertEquals(0, CollectionUtils.size(map));
+ map.put("1", "a");
+ assertEquals(1, CollectionUtils.size(map));
+ map.put("2", "b");
+ assertEquals(2, CollectionUtils.size(map));
+ }
+ public void testSize_Array() {
+ Object[] objectArray = new Object[0];
+ assertEquals(0, CollectionUtils.size(objectArray));
+
+ String[] stringArray = new String[3];
+ assertEquals(3, CollectionUtils.size(stringArray));
+ stringArray[0] = "a";
+ stringArray[1] = "b";
+ stringArray[2] = "c";
+ assertEquals(3, CollectionUtils.size(stringArray));
+ }
+ public void testSize_Enumeration() {
+ Vector list = new Vector();
+ assertEquals(0, CollectionUtils.size(list.elements()));
+ list.add("a");
+ assertEquals(1, CollectionUtils.size(list.elements()));
+ list.add("b");
+ assertEquals(2, CollectionUtils.size(list.elements()));
+ }
+ public void testSize_Iterator() {
+ List list = new ArrayList();
+ assertEquals(0, CollectionUtils.size(list.iterator()));
+ list.add("a");
+ assertEquals(1, CollectionUtils.size(list.iterator()));
+ list.add("b");
+ assertEquals(2, CollectionUtils.size(list.iterator()));
+ }
+ public void testSize_Other() {
+ try {
+ CollectionUtils.size(null);
+ fail("Expecting IllegalArgumentException");
+ } catch (IllegalArgumentException e) {}
+ try {
+ CollectionUtils.size("not a list");
+ fail("Expecting IllegalArgumentException");
+ } catch (IllegalArgumentException e) {}
+ try {
+ CollectionUtils.size(new int[0]);
+ fail("Expecting IllegalArgumentException");
+ } catch (IllegalArgumentException e) {}
+ }
+
+ //-----------------------------------------------------------------------
private static Predicate EQUALS_TWO = new Predicate() {
public boolean evaluate(Object input) {
return (input.equals("Two"));
1.57 +76 -39
jakarta-commons/collections/src/java/org/apache/commons/collections/CollectionUtils.java
Index: CollectionUtils.java
===================================================================
RCS file:
/home/cvs/jakarta-commons/collections/src/java/org/apache/commons/collections/CollectionUtils.java,v
retrieving revision 1.56
retrieving revision 1.57
diff -u -r1.56 -r1.57
--- CollectionUtils.java 18 Feb 2004 01:15:42 -0000 1.56
+++ CollectionUtils.java 31 Mar 2004 21:43:27 -0000 1.57
@@ -48,6 +48,7 @@
* @author Matthew Hawthorne
* @author Janek Bogucki
* @author Phil Steitz
+ * @author Steven Melzer
*/
public class CollectionUtils {
@@ -739,13 +740,13 @@
return ((Object[])obj)[idx];
}
else if(obj instanceof Enumeration) {
- Enumeration enum = (Enumeration)obj;
- while(enum.hasMoreElements()) {
+ Enumeration it = (Enumeration)obj;
+ while(it.hasMoreElements()) {
idx--;
if(idx == -1) {
- return enum.nextElement();
+ return it.nextElement();
} else {
- enum.nextElement();
+ it.nextElement();
}
}
}
@@ -803,55 +804,91 @@
*/
public static Object get(Object object, int index) {
if (index < 0) {
- throw new IndexOutOfBoundsException("Index cannot be negative.");
+ throw new IndexOutOfBoundsException("Index cannot be negative: " +
index);
}
- if(object instanceof Map) {
- Map map = (Map)object;
+ if (object instanceof Map) {
+ Map map = (Map) object;
Iterator iterator = map.entrySet().iterator();
return get(iterator, index);
- }
- else if(object instanceof List) {
- return ((List)object).get(index);
- }
- else if(object instanceof Object[]) {
- return ((Object[])object)[index];
- }
- else if(object instanceof Enumeration) {
- Enumeration enum = (Enumeration)object;
- while(enum.hasMoreElements()) {
+ } else if (object instanceof List) {
+ return ((List) object).get(index);
+ } else if (object instanceof Object[]) {
+ return ((Object[]) object)[index];
+ } else if (object instanceof Enumeration) {
+ Enumeration it = (Enumeration) object;
+ while (it.hasMoreElements()) {
index--;
- if(index == -1) {
- return enum.nextElement();
+ if (index == -1) {
+ return it.nextElement();
} else {
- enum.nextElement();
+ it.nextElement();
}
}
- throw new IndexOutOfBoundsException("Entry does not exist.");
- }
- else if(object instanceof Iterator) {
- return get((Iterator)object, index);
- }
- else if(object instanceof Collection) {
- Iterator iterator = ((Collection)object).iterator();
+ throw new IndexOutOfBoundsException("Entry does not exist: " + index);
+ } else if (object instanceof Iterator) {
+ Iterator it = (Iterator) object;
+ while (it.hasNext()) {
+ index--;
+ if (index == -1) {
+ return it.next();
+ } else {
+ it.next();
+ }
+ }
+ throw new IndexOutOfBoundsException("Entry does not exist: " + index);
+ } else if (object instanceof Collection) {
+ Iterator iterator = ((Collection) object).iterator();
return get(iterator, index);
} else {
- throw new IllegalArgumentException("Unsupported object type.");
+ throw new IllegalArgumentException("Unsupported object type: " +
+ (object == null ? "null" : object.getClass().getName()));
}
}
- private static Object get(Iterator iterator, int index) {
- while(iterator.hasNext()) {
- index--;
- if(index == -1) {
- return iterator.next();
- } else {
- iterator.next();
+ /**
+ * Gets the size of the collection/iterator specified.
+ * <p>
+ * This method can handles objects as follows
+ * <ul>
+ * <li>Collection - the collection size
+ * <li>Map - the map size
+ * <li>Object array - the array size
+ * <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
+ */
+ public static int size(Object object) {
+ int total = 0;
+ if (object instanceof Map) {
+ total = ((Map) object).size();
+ } else if (object instanceof Collection) {
+ total = ((Collection) object).size();
+ } else if (object instanceof Object[]) {
+ total = ((Object[]) object).length;
+ } else if (object instanceof Iterator) {
+ Iterator it = (Iterator) object;
+ while (it.hasNext()) {
+ total++;
+ it.next();
+ }
+ } else if (object instanceof Enumeration) {
+ Enumeration it = (Enumeration) object;
+ while (it.hasMoreElements()) {
+ total++;
+ it.nextElement();
}
+ } else {
+ throw new IllegalArgumentException("Unsupported object type: " +
+ (object == null ? "null" : object.getClass().getName()));
}
- throw new IndexOutOfBoundsException("Entry does not exist.");
+ return total;
}
-
- /**
+
+ /**
* Reverses the order of the given array.
*
* @param array the array to reverse
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