Rename TreeIterator to ObjectGraphIterator
git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/proper/collections/trunk@131611 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Stephen Colebourne
parent
90e7aafdc5
commit
c1d10f003e
|
|
@ -40,6 +40,7 @@ import org.apache.commons.collections.iterators.ListIteratorWrapper;
|
|||
import org.apache.commons.collections.iterators.LoopingIterator;
|
||||
import org.apache.commons.collections.iterators.ObjectArrayIterator;
|
||||
import org.apache.commons.collections.iterators.ObjectArrayListIterator;
|
||||
import org.apache.commons.collections.iterators.ObjectGraphIterator;
|
||||
import org.apache.commons.collections.iterators.SingletonIterator;
|
||||
import org.apache.commons.collections.iterators.SingletonListIterator;
|
||||
import org.apache.commons.collections.iterators.TransformIterator;
|
||||
|
|
@ -52,7 +53,7 @@ import org.apache.commons.collections.iterators.UnmodifiableMapIterator;
|
|||
* instances. The implementations are provided in the iterators subpackage.
|
||||
*
|
||||
* @since Commons Collections 2.1
|
||||
* @version $Revision: 1.22 $ $Date: 2004/02/18 01:15:42 $
|
||||
* @version $Revision: 1.23 $ $Date: 2004/03/20 00:21:08 $
|
||||
*
|
||||
* @author Stephen Colebourne
|
||||
* @author Phil Steitz
|
||||
|
|
@ -502,7 +503,65 @@ public class IteratorUtils {
|
|||
public static Iterator collatedIterator(Comparator comparator, Collection iterators) {
|
||||
return new CollatingIterator(comparator, iterators);
|
||||
}
|
||||
|
||||
|
||||
// Object Graph
|
||||
//-----------------------------------------------------------------------
|
||||
/**
|
||||
* Gets an iterator that operates over an object graph.
|
||||
* <p>
|
||||
* This iterator can extract multiple objects from a complex tree-like object graph.
|
||||
* The iteration starts from a single root object.
|
||||
* It uses a <code>Transformer</code> to extract the iterators and elements.
|
||||
* Its main benefit is that no intermediate <code>List</code> is created.
|
||||
* <p>
|
||||
* For example, consider an object graph:
|
||||
* <pre>
|
||||
* |- Branch -- Leaf
|
||||
* | \- Leaf
|
||||
* |- Tree | /- Leaf
|
||||
* | |- Branch -- Leaf
|
||||
* Forest | \- Leaf
|
||||
* | |- Branch -- Leaf
|
||||
* | | \- Leaf
|
||||
* |- Tree | /- Leaf
|
||||
* |- Branch -- Leaf
|
||||
* |- Branch -- Leaf</pre>
|
||||
* The following <code>Transformer</code>, used in this class, will extract all
|
||||
* the Leaf objects without creating a combined intermediate list:
|
||||
* <pre>
|
||||
* public Object transform(Object input) {
|
||||
* if (input instanceof Forest) {
|
||||
* return ((Forest) input).treeIterator();
|
||||
* }
|
||||
* if (input instanceof Tree) {
|
||||
* return ((Tree) input).branchIterator();
|
||||
* }
|
||||
* if (input instanceof Branch) {
|
||||
* return ((Branch) input).leafIterator();
|
||||
* }
|
||||
* if (input instanceof Leaf) {
|
||||
* return input;
|
||||
* }
|
||||
* throw new ClassCastException();
|
||||
* }</pre>
|
||||
* <p>
|
||||
* Internally, iteration starts from the root object. When next is called,
|
||||
* the transformer is called to examine the object. The transformer will return
|
||||
* either an iterator or an object. If the object is an Iterator, the next element
|
||||
* from that iterator is obtained and the process repeats. If the element is an object
|
||||
* it is returned.
|
||||
* <p>
|
||||
* Under many circumstances, linking Iterators together in this manner is
|
||||
* more efficient (and convenient) than using nested for loops to extract a list.
|
||||
*
|
||||
* @param root the root object to start iterating from, null results in an empty iterator
|
||||
* @param transformer the transformer to use, see above, null uses no effect transformer
|
||||
* @return
|
||||
*/
|
||||
public static Iterator objectGraphIterator(Object root, Transformer transformer) {
|
||||
return new ObjectGraphIterator(root, transformer);
|
||||
}
|
||||
|
||||
// Transformed
|
||||
//-----------------------------------------------------------------------
|
||||
/**
|
||||
|
|
|
|||
|
|
@ -71,11 +71,11 @@ import org.apache.commons.collections.TransformerUtils;
|
|||
* more efficient (and convenient) than using nested for loops to extract a list.
|
||||
*
|
||||
* @since Commons Collections 3.1
|
||||
* @version $Revision: 1.1 $ $Date: 2004/03/14 23:27:22 $
|
||||
* @version $Revision: 1.1 $ $Date: 2004/03/20 00:21:08 $
|
||||
*
|
||||
* @author Stephen Colebourne
|
||||
*/
|
||||
public class TreeIterator implements Iterator {
|
||||
public class ObjectGraphIterator implements Iterator {
|
||||
|
||||
/** The stack of iterators */
|
||||
protected final ArrayStack stack = new ArrayStack(8);
|
||||
|
|
@ -95,7 +95,7 @@ public class TreeIterator implements Iterator {
|
|||
|
||||
//-----------------------------------------------------------------------
|
||||
/**
|
||||
* Constructs a TreeIterator using a root object and transformer.
|
||||
* Constructs an ObjectGraphIterator using a root object and transformer.
|
||||
* <p>
|
||||
* The root object can be an iterator, in which case it will be immediately
|
||||
* looped around.
|
||||
|
|
@ -103,7 +103,7 @@ public class TreeIterator implements Iterator {
|
|||
* @param root the root object, null will result in an empty iterator
|
||||
* @param transformer the transformer to use, null will use a no effect transformer
|
||||
*/
|
||||
public TreeIterator(Object root, Transformer transformer) {
|
||||
public ObjectGraphIterator(Object root, Transformer transformer) {
|
||||
super();
|
||||
if (root instanceof Iterator) {
|
||||
this.currentIterator = (Iterator) root;
|
||||
|
|
@ -114,7 +114,7 @@ public class TreeIterator implements Iterator {
|
|||
}
|
||||
|
||||
/**
|
||||
* Constructs a TreeIterator that will handle an iterator of iterators.
|
||||
* Constructs a ObjectGraphIterator that will handle an iterator of iterators.
|
||||
* <p>
|
||||
* This constructor exists for convenience to emphasise that this class can
|
||||
* be used to iterate over nested iterators. That is to say that the iterator
|
||||
|
|
@ -123,7 +123,7 @@ public class TreeIterator implements Iterator {
|
|||
*
|
||||
* @param rootIterator the root iterator, null will result in an empty iterator
|
||||
*/
|
||||
public TreeIterator(Iterator rootIterator) {
|
||||
public ObjectGraphIterator(Iterator rootIterator) {
|
||||
super();
|
||||
this.currentIterator = rootIterator;
|
||||
this.transformer = TransformerUtils.nopTransformer();
|
||||
|
|
@ -189,7 +189,7 @@ public class TreeIterator implements Iterator {
|
|||
|
||||
//-----------------------------------------------------------------------
|
||||
/**
|
||||
* Checks whether there are any more elements in the tree to obtain.
|
||||
* Checks whether there are any more elements in the iteration to obtain.
|
||||
*
|
||||
* @return true if elements remain in the iteration
|
||||
*/
|
||||
|
|
@ -22,7 +22,7 @@ import junit.framework.TestSuite;
|
|||
/**
|
||||
* Entry point for all iterator tests.
|
||||
*
|
||||
* @version $Revision: 1.13 $ $Date: 2004/03/14 23:27:22 $
|
||||
* @version $Revision: 1.14 $ $Date: 2004/03/20 00:21:08 $
|
||||
*
|
||||
* @author Rodney Waldhoff
|
||||
*/
|
||||
|
|
@ -49,7 +49,7 @@ public class TestAll extends TestCase {
|
|||
suite.addTest(TestLoopingIterator.suite());
|
||||
suite.addTest(TestSingletonIterator.suite());
|
||||
suite.addTest(TestSingletonListIterator.suite());
|
||||
suite.addTest(TestTreeIterator.suite());
|
||||
suite.addTest(TestObjectGraphIterator.suite());
|
||||
suite.addTest(TestUniqueFilterIterator.suite());
|
||||
suite.addTest(TestUnmodifiableIterator.suite());
|
||||
suite.addTest(TestUnmodifiableListIterator.suite());
|
||||
|
|
|
|||
|
|
@ -30,11 +30,11 @@ import org.apache.commons.collections.Transformer;
|
|||
/**
|
||||
* Testcase.
|
||||
*
|
||||
* @version $Revision: 1.1 $ $Date: 2004/03/14 23:27:22 $
|
||||
* @version $Revision: 1.1 $ $Date: 2004/03/20 00:21:08 $
|
||||
*
|
||||
* @author Stephen Colebourne
|
||||
*/
|
||||
public class TestTreeIterator extends AbstractTestIterator {
|
||||
public class TestObjectGraphIterator extends AbstractTestIterator {
|
||||
|
||||
protected String[] testArray = { "One", "Two", "Three", "Four", "Five", "Six" };
|
||||
|
||||
|
|
@ -43,7 +43,7 @@ public class TestTreeIterator extends AbstractTestIterator {
|
|||
protected List list3 = null;
|
||||
protected List iteratorList = null;
|
||||
|
||||
public TestTreeIterator(String testName) {
|
||||
public TestObjectGraphIterator(String testName) {
|
||||
super(testName);
|
||||
}
|
||||
|
||||
|
|
@ -52,7 +52,7 @@ public class TestTreeIterator extends AbstractTestIterator {
|
|||
}
|
||||
|
||||
public static Test suite() {
|
||||
return new TestSuite(TestTreeIterator.class);
|
||||
return new TestSuite(TestObjectGraphIterator.class);
|
||||
}
|
||||
|
||||
public void setUp() {
|
||||
|
|
@ -74,16 +74,16 @@ public class TestTreeIterator extends AbstractTestIterator {
|
|||
//-----------------------------------------------------------------------
|
||||
public Iterator makeEmptyIterator() {
|
||||
ArrayList list = new ArrayList();
|
||||
return new TreeIterator(list.iterator(), null);
|
||||
return new ObjectGraphIterator(list.iterator(), null);
|
||||
}
|
||||
|
||||
public Iterator makeFullIterator() {
|
||||
return new TreeIterator(iteratorList.iterator(), null);
|
||||
return new ObjectGraphIterator(iteratorList.iterator(), null);
|
||||
}
|
||||
|
||||
//-----------------------------------------------------------------------
|
||||
public void testIteratorConstructor_null1() {
|
||||
Iterator it = new TreeIterator(null);
|
||||
Iterator it = new ObjectGraphIterator(null);
|
||||
|
||||
assertEquals(false, it.hasNext());
|
||||
try {
|
||||
|
|
@ -99,7 +99,7 @@ public class TestTreeIterator extends AbstractTestIterator {
|
|||
}
|
||||
|
||||
public void testIteratorConstructor_null_next() {
|
||||
Iterator it = new TreeIterator(null);
|
||||
Iterator it = new ObjectGraphIterator(null);
|
||||
try {
|
||||
it.next();
|
||||
fail();
|
||||
|
|
@ -108,7 +108,7 @@ public class TestTreeIterator extends AbstractTestIterator {
|
|||
}
|
||||
|
||||
public void testIteratorConstructor_null_remove() {
|
||||
Iterator it = new TreeIterator(null);
|
||||
Iterator it = new ObjectGraphIterator(null);
|
||||
try {
|
||||
it.remove();
|
||||
fail();
|
||||
|
|
@ -119,7 +119,7 @@ public class TestTreeIterator extends AbstractTestIterator {
|
|||
//-----------------------------------------------------------------------
|
||||
public void testIteratorConstructorIteration_Empty() {
|
||||
List iteratorList = new ArrayList();
|
||||
Iterator it = new TreeIterator(iteratorList.iterator());
|
||||
Iterator it = new ObjectGraphIterator(iteratorList.iterator());
|
||||
|
||||
assertEquals(false, it.hasNext());
|
||||
try {
|
||||
|
|
@ -139,7 +139,7 @@ public class TestTreeIterator extends AbstractTestIterator {
|
|||
iteratorList.add(list1.iterator());
|
||||
iteratorList.add(list2.iterator());
|
||||
iteratorList.add(list3.iterator());
|
||||
Iterator it = new TreeIterator(iteratorList.iterator());
|
||||
Iterator it = new ObjectGraphIterator(iteratorList.iterator());
|
||||
|
||||
for (int i = 0; i < 6; i++) {
|
||||
assertEquals(true, it.hasNext());
|
||||
|
|
@ -158,7 +158,7 @@ public class TestTreeIterator extends AbstractTestIterator {
|
|||
iteratorList.add(list1.iterator());
|
||||
iteratorList.add(list2.iterator());
|
||||
iteratorList.add(list3.iterator());
|
||||
Iterator it = new TreeIterator(iteratorList.iterator());
|
||||
Iterator it = new ObjectGraphIterator(iteratorList.iterator());
|
||||
|
||||
for (int i = 0; i < 6; i++) {
|
||||
assertEquals(testArray[i], it.next());
|
||||
|
|
@ -179,7 +179,7 @@ public class TestTreeIterator extends AbstractTestIterator {
|
|||
iteratorList.add(IteratorUtils.EMPTY_ITERATOR);
|
||||
iteratorList.add(list3.iterator());
|
||||
iteratorList.add(IteratorUtils.EMPTY_ITERATOR);
|
||||
Iterator it = new TreeIterator(iteratorList.iterator());
|
||||
Iterator it = new ObjectGraphIterator(iteratorList.iterator());
|
||||
|
||||
for (int i = 0; i < 6; i++) {
|
||||
assertEquals(true, it.hasNext());
|
||||
|
|
@ -198,7 +198,7 @@ public class TestTreeIterator extends AbstractTestIterator {
|
|||
iteratorList.add(list1.iterator());
|
||||
iteratorList.add(list2.iterator());
|
||||
iteratorList.add(list3.iterator());
|
||||
Iterator it = new TreeIterator(iteratorList.iterator());
|
||||
Iterator it = new ObjectGraphIterator(iteratorList.iterator());
|
||||
|
||||
for (int i = 0; i < 6; i++) {
|
||||
assertEquals(testArray[i], it.next());
|
||||
|
|
@ -216,7 +216,7 @@ public class TestTreeIterator extends AbstractTestIterator {
|
|||
iteratorList.add(list1.iterator());
|
||||
iteratorList.add(list2.iterator());
|
||||
iteratorList.add(list3.iterator());
|
||||
Iterator it = new TreeIterator(iteratorList.iterator(), null);
|
||||
Iterator it = new ObjectGraphIterator(iteratorList.iterator(), null);
|
||||
|
||||
for (int i = 0; i < 6; i++) {
|
||||
assertEquals(true, it.hasNext());
|
||||
|
|
@ -234,7 +234,7 @@ public class TestTreeIterator extends AbstractTestIterator {
|
|||
iteratorList.add(IteratorUtils.EMPTY_ITERATOR);
|
||||
iteratorList.add(list3.iterator());
|
||||
iteratorList.add(IteratorUtils.EMPTY_ITERATOR);
|
||||
Iterator it = new TreeIterator(iteratorList.iterator(), null);
|
||||
Iterator it = new ObjectGraphIterator(iteratorList.iterator(), null);
|
||||
|
||||
for (int i = 0; i < 6; i++) {
|
||||
assertEquals(true, it.hasNext());
|
||||
|
|
@ -245,7 +245,7 @@ public class TestTreeIterator extends AbstractTestIterator {
|
|||
|
||||
//-----------------------------------------------------------------------
|
||||
public void testIteration_RootNull() {
|
||||
Iterator it = new TreeIterator(null, null);
|
||||
Iterator it = new ObjectGraphIterator(null, null);
|
||||
|
||||
assertEquals(false, it.hasNext());
|
||||
try {
|
||||
|
|
@ -262,7 +262,7 @@ public class TestTreeIterator extends AbstractTestIterator {
|
|||
|
||||
public void testIteration_RootNoTransformer() {
|
||||
Forest forest = new Forest();
|
||||
Iterator it = new TreeIterator(forest, null);
|
||||
Iterator it = new ObjectGraphIterator(forest, null);
|
||||
|
||||
assertEquals(true, it.hasNext());
|
||||
assertSame(forest, it.next());
|
||||
|
|
@ -277,7 +277,7 @@ public class TestTreeIterator extends AbstractTestIterator {
|
|||
public void testIteration_Transformed1() {
|
||||
Forest forest = new Forest();
|
||||
Leaf l1 = forest.addTree().addBranch().addLeaf();
|
||||
Iterator it = new TreeIterator(forest, new LeafFinder());
|
||||
Iterator it = new ObjectGraphIterator(forest, new LeafFinder());
|
||||
|
||||
assertEquals(true, it.hasNext());
|
||||
assertSame(l1, it.next());
|
||||
|
|
@ -305,7 +305,7 @@ public class TestTreeIterator extends AbstractTestIterator {
|
|||
Leaf l4 = b3.addLeaf();
|
||||
Leaf l5 = b5.addLeaf();
|
||||
|
||||
Iterator it = new TreeIterator(forest, new LeafFinder());
|
||||
Iterator it = new ObjectGraphIterator(forest, new LeafFinder());
|
||||
|
||||
assertEquals(true, it.hasNext());
|
||||
assertSame(l1, it.next());
|
||||
|
|
@ -341,7 +341,7 @@ public class TestTreeIterator extends AbstractTestIterator {
|
|||
Leaf l4 = b3.addLeaf();
|
||||
Leaf l5 = b4.addLeaf();
|
||||
|
||||
Iterator it = new TreeIterator(forest, new LeafFinder());
|
||||
Iterator it = new ObjectGraphIterator(forest, new LeafFinder());
|
||||
|
||||
assertEquals(true, it.hasNext());
|
||||
assertSame(l1, it.next());
|
||||
Loading…
Reference in New Issue