001// Copyright 2007, 2008 The Apache Software Foundation
002//
003// Licensed under the Apache License, Version 2.0 (the "License");
004// you may not use this file except in compliance with the License.
005// You may obtain a copy of the License at
006//
007//     http://www.apache.org/licenses/LICENSE-2.0
008//
009// Unless required by applicable law or agreed to in writing, software
010// distributed under the License is distributed on an "AS IS" BASIS,
011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012// See the License for the specific language governing permissions and
013// limitations under the License.
014
015package org.apache.tapestry5.upload.internal.services;
016
017import static org.apache.tapestry5.commons.util.CollectionFactory.newList;
018
019import java.util.List;
020
021/**
022 * Holds single or multivalued values.
023 */
024public class ParameterValue
025{
026    private final List<String> values = newList();
027
028    public static final ParameterValue NULL = new ParameterValue()
029    {
030        @Override
031        public String single()
032        {
033            return null;
034        }
035
036        @Override
037        public String[] multi()
038        {
039            return null;
040        }
041    };
042
043    public ParameterValue(String value)
044    {
045        values.add(value);
046    }
047
048    public ParameterValue(String... values)
049    {
050        for (String v : values)
051        {
052            add(v);
053        }
054    }
055
056    /**
057     * @return Single value of parameter (or first value if there are multiple values)
058     */
059    public String single()
060    {
061        return values.get(0);
062    }
063
064    /**
065     * @return All values of parameter
066     */
067    public String[] multi()
068    {
069        return values.toArray(new String[values.size()]);
070    }
071
072    public void add(String value)
073    {
074        values.add(value);
075    }
076
077    public boolean isMulti()
078    {
079        return values.size() > 1;
080    }
081}