001    // Copyright 2004, 2005 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.tapestry.coerce;
016    
017    import java.util.Collection;
018    
019    /**
020     * Converts from {@link java.util.Collection}to Boolean; a non-empty collection is true.
021     * 
022     * @author Howard M. Lewis Ship
023     */
024    public final class CollectionToBooleanConverter implements TypeConverter
025    {
026        public Object convertValue(Object value)
027        {
028            Collection c = (Collection) value;
029    
030            return c.isEmpty() ? Boolean.FALSE : Boolean.TRUE;
031        }
032    
033    }