| /* |
| * Copyright (c) 2003 The Visigoth Software Society. 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 acknowledgement: |
| * "This product includes software developed by the |
| * Visigoth Software Society (http://www.visigoths.org/)." |
| * Alternately, this acknowledgement may appear in the software itself, |
| * if and wherever such third-party acknowledgements normally appear. |
| * |
| * 4. Neither the name "FreeMarker", "Visigoth", nor any of the names of the |
| * project contributors may be used to endorse or promote products derived |
| * from this software without prior written permission. For written |
| * permission, please contact visigoths@visigoths.org. |
| * |
| * 5. Products derived from this software may not be called "FreeMarker" or "Visigoth" |
| * nor may "FreeMarker" or "Visigoth" appear in their names |
| * without prior written permission of the Visigoth Software Society. |
| * |
| * 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 VISIGOTH SOFTWARE SOCIETY 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 Visigoth Software Society. For more |
| * information on the Visigoth Software Society, please see |
| * http://www.visigoths.org/ |
| */ |
| |
| package freemarker.ext.beans; |
| |
| import java.util.Iterator; |
| import java.util.NoSuchElementException; |
| |
| import freemarker.template.TemplateCollectionModel; |
| import freemarker.template.TemplateModel; |
| import freemarker.template.TemplateModelException; |
| import freemarker.template.TemplateModelIterator; |
| |
| /** |
| * <p>A class that adds {@link TemplateModelIterator} functionality to the |
| * {@link Iterator} interface implementers. |
| * </p> |
| * <p>It differs from the {@link freemarker.template.SimpleCollection} in that |
| * it inherits from {@link BeanModel}, and therefore you can call methods on |
| * it directly, even to the effect of calling <tt>iterator.remove()</tt> in |
| * the template.</p> <p>Using the model as a collection model is NOT |
| * thread-safe, as iterators are inherently not thread-safe. |
| * Further, you can iterate over it only once. Attempts to call the |
| * {@link #iterator()} method after it was already driven to the end once will |
| * throw an exception.</p> |
| * @author Attila Szegedi |
| */ |
| |
| public class IteratorModel |
| extends |
| BeanModel |
| implements |
| TemplateModelIterator, |
| TemplateCollectionModel |
| { |
| private boolean accessed = false; |
| |
| /** |
| * Creates a new model that wraps the specified iterator object. |
| * @param iterator the iterator object to wrap into a model. |
| * @param wrapper the {@link BeansWrapper} associated with this model. |
| * Every model has to have an associated {@link BeansWrapper} instance. The |
| * model gains many attributes from its wrapper, including the caching |
| * behavior, method exposure level, method-over-item shadowing policy etc. |
| */ |
| public IteratorModel(Iterator iterator, BeansWrapper wrapper) |
| { |
| super(iterator, wrapper); |
| } |
| |
| /** |
| * This allows the iterator to be used in a <tt><foreach></tt> block. |
| * @return "this" |
| */ |
| public TemplateModelIterator iterator() throws TemplateModelException |
| { |
| synchronized(this) { |
| if(accessed) { |
| throw new TemplateModelException( |
| "This collection is stateful and can not be iterated over the" + |
| " second time."); |
| } |
| accessed = true; |
| } |
| return this; |
| } |
| |
| /** |
| * Calls underlying {@link Iterator#hasNext()}. |
| */ |
| public boolean hasNext() { |
| return ((Iterator)object).hasNext(); |
| } |
| |
| |
| /** |
| * Calls underlying {@link Iterator#next()} and wraps the result. |
| */ |
| public TemplateModel next() |
| throws |
| TemplateModelException |
| { |
| try { |
| return wrap(((Iterator)object).next()); |
| } |
| catch(NoSuchElementException e) { |
| throw new TemplateModelException( |
| "No more elements in the iterator.", e); |
| } |
| } |
| |
| /** |
| * Returns {@link Iterator#hasNext()}. Therefore, an |
| * iterator that has no more element evaluates to false, and an |
| * iterator that has further elements evaluates to true. |
| */ |
| public boolean getAsBoolean() { |
| return hasNext(); |
| } |
| } |