001    // Copyright 2010 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    
015    package org.apache.tapestry5.ioc.util;
016    
017    import java.util.Collection;
018    import java.util.Collections;
019    import java.util.List;
020    import java.util.Map;
021    
022    import org.apache.tapestry5.ioc.internal.util.CollectionFactory;
023    import org.apache.tapestry5.ioc.internal.util.InternalUtils;
024    
025    /**
026     * Used (as part of a {@link UnknownValueException} to identify what available values
027     * are present.
028     * 
029     * @since 5.2.0
030     */
031    public class AvailableValues
032    {
033        private final String valueType;
034    
035        private final List<String> values;
036    
037        /**
038         * @param valueType
039         *            a word or phrase that describes what the values are such as "component types" or "service ids"
040         *@param values
041         *            a set of objects defining the values; the values will be converted to strings and sorted into
042         *            ascending order
043         */
044        public AvailableValues(String valueType, Collection<?> values)
045        {
046            this.valueType = valueType;
047            this.values = sortValues(values);
048        }
049    
050        public AvailableValues(String valueType, Map<?, ?> map)
051        {
052            this(valueType, map.keySet());
053        }
054    
055        private static List<String> sortValues(Collection<?> values)
056        {
057            List<String> result = CollectionFactory.newList();
058    
059            for (Object v : values)
060            {
061                result.add(String.valueOf(v));
062            }
063    
064            Collections.sort(result);
065    
066            return Collections.unmodifiableList(result);
067        }
068    
069        /** The type of value, i.e., "component types" or "service ids". */
070        public String getValueType()
071        {
072            return valueType;
073        }
074    
075        /** The values, as strings, in sorted order. */
076        public List<String> getValues()
077        {
078            return values;
079        }
080    
081        @Override
082        public String toString()
083        {
084            return String.format("AvailableValues[%s: %s]", valueType, InternalUtils.join(values));
085        }
086    
087    }