jstrachan 01/08/22 00:43:53
Added: collections/src/java/org/apache/commons/collections
SingletonIterator.java
collections/src/test/org/apache/commons/collections
TestSingletonIterator.java
Log:
Added SingletonIterator for iterating over a single value together with a JUnit test
case
Revision Changes Path
1.1
jakarta-commons/collections/src/java/org/apache/commons/collections/SingletonIterator.java
Index: SingletonIterator.java
===================================================================
/*
* Copyright (C) The Apache Software Foundation. All rights reserved.
*
* This software is published under the terms of the Apache Software License
* version 1.1, a copy of which has been included with this distribution in
* the LICENSE file.
*/
package org.apache.commons.collections;
import java.util.Iterator;
import java.util.NoSuchElementException;
/** <p><code>SingleIterator</code> is an {@link Iterator} over a single
* object instance.</p>
*
* @author <a href="mailto:[EMAIL PROTECTED]";>James Strachan</a>
* @version $Revision: 1.1 $
*/
public class SingletonIterator implements Iterator {
private boolean first = true;
private Object object;
public SingletonIterator(Object object) {
this.object = object;
}
public boolean hasNext() {
return first;
}
public Object next() {
if (! first ) {
throw new NoSuchElementException();
}
Object answer = object;
object = null;
first = false;
return answer;
}
public void remove() {
throw new UnsupportedOperationException( "remove() is not supported by this
iterator" );
}
}
1.1
jakarta-commons/collections/src/test/org/apache/commons/collections/TestSingletonIterator.java
Index: TestSingletonIterator.java
===================================================================
/*
* $Header:
/home/cvs/jakarta-commons/collections/src/test/org/apache/commons/collections/TestSingletonIterator.java,v
1.1 2001/08/22 07:43:53 jstrachan Exp $
* $Revision: 1.1 $
* $Date: 2001/08/22 07:43:53 $
*
* ====================================================================
*
* The Apache Software License, Version 1.1
*
* Copyright (c) 1999-2001 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The Jakarta Project", "Commons", and "Apache Software
* Foundation" must not be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact [EMAIL PROTECTED]
*
* 5. Products derived from this software may not be called "Apache"
* nor may "Apache" appear in their names without prior written
* permission of the Apache Group.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apache.commons.collections;
import junit.framework.*;
import java.util.Iterator;
import java.util.NoSuchElementException;
/**
* Tests the SingletonIterator to ensure that the next() method will actually
* perform the iteration rather than the hasNext() method.
*
* @author James Strachan
* @version $Id: TestSingletonIterator.java,v 1.1 2001/08/22 07:43:53 jstrachan Exp
$
*/
public class TestSingletonIterator extends TestObject {
private static final Object testValue = "foo";
public static Test suite() {
return new TestSuite(TestSingletonIterator.class);
}
public TestSingletonIterator(String testName) {
super(testName);
}
/**
* Return a new, empty {@link Object} to used for testing.
*/
public Object makeObject() {
return new SingletonIterator( testValue );
}
public void testIterator() {
Iterator iter = (Iterator) makeObject();
assertTrue( "Iterator has a first item", iter.hasNext() );
Object iterValue = iter.next();
assertEquals( "Iteration value is correct", testValue, iterValue );
assertTrue("Iterator should now be empty", ! iter.hasNext() );
try {
Object testValue = iter.next();
}
catch (Exception e) {
assertTrue("NoSuchElementException must be thrown",
e.getClass().equals((new NoSuchElementException()).getClass()));
}
}
}
