001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.commons.functor.core.composite;
018    
019    import org.apache.commons.functor.Predicate;
020    import org.apache.commons.functor.Procedure;
021    
022    import java.io.Serializable;
023    
024    /**
025     * Abstract base class for {@link WhileDoProcedure} and {@link DoWhileProcedure}
026     * used to implement loop procedures.
027     * <p>
028     * @version $Revision: 1171154 $ $Date: 2011-09-15 17:58:38 +0200 (Thu, 15 Sep 2011) $
029     * @author Herve Quiroz
030     * @author Rodney Waldhoff
031     */
032    public abstract class AbstractLoopProcedure implements Procedure, Serializable {
033        /**
034         * serialVersionUID declaration.
035         */
036        private static final long serialVersionUID = -5903381842630236070L;
037    
038        /** Base hash integer used to shift hash */
039        private static final int HASH_SHIFT = 4;
040    
041        private final Predicate condition;
042        private final Procedure action;
043    
044        /**
045         * Create a new AbstractLoopProcedure.
046         * @param condition while true, repeat
047         * @param action loop body
048         */
049        protected AbstractLoopProcedure(Predicate condition, Procedure action) {
050            this.condition = condition;
051            this.action = action;
052        }
053    
054        /**
055         * {@inheritDoc}
056         */
057        public final boolean equals(Object object) {
058            if (object == this) {
059                return true;
060            }
061            if (!(object instanceof AbstractLoopProcedure)) {
062                return false;
063            }
064            AbstractLoopProcedure that = (AbstractLoopProcedure) object;
065            return (null == getCondition() ? null == that.getCondition() : getCondition().equals(that.getCondition()))
066                    && (null == getAction() ? null == that.getAction() : getAction().equals(that.getAction()));
067        }
068    
069        /**
070         * {@inheritDoc}
071         */
072        public int hashCode() {
073            return hashCode("AbstractLoopProcedure".hashCode());
074        }
075    
076        /**
077         * {@inheritDoc}
078         */
079        public String toString() {
080            return getClass().getName() + "<" + getCondition() + "," + getAction() + ">";
081        }
082    
083        /**
084         * Create a hashCode by manipulating an input hashCode and factoring in instance state.
085         * @param hash incoming hashCode
086         * @return int
087         */
088        protected int hashCode(int hash) {
089            hash <<= HASH_SHIFT;
090            if (null != getAction()) {
091                hash ^= getAction().hashCode();
092            }
093            hash <<= HASH_SHIFT;
094            if (null != getCondition()) {
095                hash ^= getCondition().hashCode();
096            }
097            return hash;
098        }
099    
100        /**
101         * Get the condition.
102         * @return Predicate
103         */
104        protected final Predicate getCondition() {
105            return condition;
106        }
107    
108        /**
109         * Get the action.
110         * @return Procedure
111         */
112        protected final Procedure getAction() {
113            return action;
114        }
115    
116    }