/*
 *  Copyright 2001-2004 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.commons.collections.functors;

import java.io.Serializable;

import org.apache.commons.collections.Predicate;

/**
 * Predicate implementation that returns true if both the predicates return true.
 * 
 * @since Commons Collections 3.0
 * @version $Revision: 1.6 $ $Date: 2004/05/31 16:43:17 $
 *
 * @author Stephen Colebourne
 */
public final class AndPredicate implements Predicate, PredicateDecorator, Serializable {

    /** Serial version UID */
    static final long serialVersionUID = 4189014213763186912L;
    
    /** The array of predicates to call */
    private final Predicate iPredicate1;
    /** The array of predicates to call */
    private final Predicate iPredicate2;
    
    /**
     * Factory to create the predicate.
     * 
     * @param predicate1  the first predicate to check, not null
     * @param predicate2  the second predicate to check, not null
     * @return the and predicate
     * @throws IllegalArgumentException if either predicate is null
     */
    public static Predicate getInstance(Predicate predicate1, Predicate predicate2) {
        if (predicate1 == null || predicate2 == null) {
            throw new IllegalArgumentException("Predicate must not be null");
        }
        return new AndPredicate(predicate1, predicate2);
    }

    /**
     * Constructor that performs no validation.
     * Use getInstance if you want that.
     * 
     * @param predicate1  the first predicate to check, not null
     * @param predicate2  the second predicate to check, not null
     */
    public AndPredicate(Predicate predicate1, Predicate predicate2) {
        super();
        iPredicate1 = predicate1;
        iPredicate2 = predicate2;
    }

    /**
     * Evaluates the predicate returning true if both predicates return true.
     * 
     * @param object  the input object
     * @return true if both decorated predicates return true
     */
    public boolean evaluate(Object object) {
       return (iPredicate1.evaluate(object) && iPredicate2.evaluate(object));
    }

    /**
     * Gets the two predicates being decorated as an array.
     * 
     * @return the predicates
     * @since Commons Collections 3.1
     */
    public Predicate[] getPredicates() {
        return new Predicate[] {iPredicate1, iPredicate2};
    }

}