tapestry/tapestry-framework/src/java/org/apache/tapestry/coerce/CollectionToBooleanConverter.java

// Copyright 2004, 2005 The Apache Software Foundation
//
// Licensed 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.tapestry.coerce;

import java.util.Collection;

/**
 * Converts from {@link java.util.Collection}to Boolean; a non-empty collection is true.
 * 
 * @author Howard M. Lewis Ship
 */
public final class CollectionToBooleanConverter implements TypeConverter
{
    public Object convertValue(Object value)
    {
        Collection c = (Collection) value;

        return c.isEmpty() ? Boolean.FALSE : Boolean.TRUE;
    }

}