/*
 * Copyright 2004-2010 the Seasar Foundation and the Others.
 *
 * 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.slim3.datastore;

import com.google.appengine.api.datastore.Query.FilterOperator;

/**
 * An implementation class for "is not null" filter.
 * 
 * @author higa
 * @since 1.0.0
 * 
 */
public class IsNotNullCriterion extends InMemoryIsNotNullCriterion implements
        FilterCriterion {

    /**
     * The array of {@link Filter}s.
     */
    protected Filter[] filters;

    /**
     * Constructor.
     * 
     * @param attributeMeta
     *            the meta data of attribute
     * @throws NullPointerException
     *             if the attributeMeta parameter is null
     */
    public IsNotNullCriterion(AbstractAttributeMeta<?, ?> attributeMeta)
            throws NullPointerException {
        super(attributeMeta);
        filters =
            new Filter[] { new Filter(
                attributeMeta.getName(),
                FilterOperator.GREATER_THAN,
                null) };
    }

    public Filter[] getFilters() {
        return filters;
    }
}