Struts example source code file (SortIteratorFilter.java)

This example Struts source code file (SortIteratorFilter.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Struts tags/keywords

comparator, error, error, iterator, iterator, iteratorfiltersupport, list, object, object, remove, sortiterator, sortiteratorfilter, sortiteratorfilter, unsupportedoperationexception, util

The Struts SortIteratorFilter.java source code

/*
 * $Id: SortIteratorFilter.java 651946 2008-04-27 13:41:38Z apetrelli $
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.struts2.util;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;

import com.opensymphony.xwork2.Action;
import com.opensymphony.xwork2.util.logging.LoggerFactory;


/**
 * A bean that takes a source and comparator then attempt to sort the source
 * utilizing the comparator. It is being used in SortIteratorTag.
 *
 * @see org.apache.struts2.views.jsp.iterator.SortIteratorTag
 */
public class SortIteratorFilter extends IteratorFilterSupport implements Iterator, Action {

    Comparator comparator;
    Iterator iterator;
    List list;

    // Attributes ----------------------------------------------------
    Object source;


    public void setComparator(Comparator aComparator) {
        this.comparator = aComparator;
    }

    public List getList() {
        return list;
    }

    // Public --------------------------------------------------------
    public void setSource(Object anIterator) {
        source = anIterator;
    }

    // Action implementation -----------------------------------------
    public String execute() {
        if (source == null) {
            return ERROR;
        } else {
            try {
                if (!MakeIterator.isIterable(source)) {
                    LoggerFactory.getLogger(SortIteratorFilter.class.getName()).warn("Cannot create SortIterator for source " + source);

                    return ERROR;
                }

                list = new ArrayList();

                Iterator i = MakeIterator.convert(source);

                while (i.hasNext()) {
                    list.add(i.next());
                }

                // Sort it
                Collections.sort(list, comparator);
                iterator = list.iterator();

                return SUCCESS;
            } catch (Exception e) {
                LoggerFactory.getLogger(SortIteratorFilter.class.getName()).warn("Error creating sort iterator.", e);

                return ERROR;
            }
        }
    }

    // Iterator implementation ---------------------------------------
    public boolean hasNext() {
        return (source == null) ? false : iterator.hasNext();
    }

    public Object next() {
        return iterator.next();
    }

    public void remove() {
        throw new UnsupportedOperationException("Remove is not supported in SortIteratorFilter.");
    }
}