org.zebrafish.feature.AbstractFieldList.java Source code

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Here is the source code for org.zebrafish.feature.AbstractFieldList.java

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/*
 * $Id$
 *
 * @(#)AbstractFieldList.java 2008/5/24
 *  
 * Copyright (c) 2008 Joseph S. Kuo, Max Chu
 * All Rights Reserved.
 *
 * --LICENSE NOTICE--
 * This file is part of Zebrafish, which is a Java wrapper for Google
 * Chart API.
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library.  If not, see 
 * <http://www.gnu.org/licenses/>.
 * --LICENSE NOTICE--
 */

package org.zebrafish.feature;

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

import org.apache.commons.lang.StringUtils;
import org.zebrafish.field.Field;
import org.zebrafish.util.Separator;

/**
 * An abstract implementation for {@link FieldList}.
 * 
 * @author Max Chu
 * @author Joseph S. Kuo
 * @version $Revision$, $Date$
 * @param <T> type extended from <code>Field</code>
 * @since 0.1
 */
public abstract class AbstractFieldList<T extends Field> extends AbstractFeature implements FieldList<T> {
    private List<T> list;

    private void checkList() {
        if (list == null) {
            list = new ArrayList<T>();
        }
    }

    public void add(T field) {
        if (field == null) {
            return;
        }
        checkList();
        list.add(field);
    }

    public void add(int index, T field) {
        if (field == null) {
            return;
        }
        checkList();
        list.add(index, field);
    }

    public void clear() {
        if (list == null) {
            return;
        }
        list.clear();
    }

    public boolean contains(T field) {
        return indexOf(field) != -1;
    }

    public T get(int index) {
        return list == null ? null : list.get(index);
    }

    public int indexOf(T field) {
        return list == null || field == null ? -1 : list.indexOf(field);
    }

    public boolean isEmpty() {
        return list == null ? true : list.isEmpty();
    }

    public T remove(int index) {
        return list == null ? null : list.remove(index);
    }

    public boolean remove(T field) {
        return list == null || field == null ? false : list.remove(field);
    }

    public T set(int index, T field) {
        if (field == null) {
            return null;
        }
        checkList();
        return list.set(index, field);
    }

    public int size() {
        return list == null ? 0 : list.size();
    }

    /**
     * Returns the separator used between each field.
     * 
     * @return the separator used between each field
     */
    protected Separator getSeparator() {
        return Separator.BAR;
    }

    public Iterator<T> iterator() {
        checkList();
        return list.iterator();
    }

    public String toURLString() {
        if (isEmpty()) {
            return StringUtils.EMPTY;
        }

        StringBuffer sb = createStringBuffer();
        for (T t : this) {
            String fieldURLString = t.toURLString();
            if (StringUtils.isNotEmpty(fieldURLString)) {
                sb.append(fieldURLString);
                sb.append(getSeparator());
            }
        }

        return sb.charAt(sb.length() - 1) == Separator.EQUAL.getSymbol() ? StringUtils.EMPTY
                : sb.deleteCharAt(sb.length() - 1).toString();
    }
}