| /* |
| * Copyright 2003,2004 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.functor.adapter; |
| |
| import java.io.Serializable; |
| |
| import org.apache.commons.functor.Procedure; |
| import org.apache.commons.functor.UnaryProcedure; |
| |
| /** |
| * Adapts a |
| * {@link UnaryProcedure UnaryProcedure} |
| * to the |
| * {@link Procedure Procedure} interface |
| * using a constant unary argument. |
| * <p/> |
| * Note that although this class implements |
| * {@link Serializable}, a given instance will |
| * only be truly <code>Serializable</code> if the |
| * underlying objects are. Attempts to serialize |
| * an instance whose delegates are not |
| * <code>Serializable</code> will result in an exception. |
| * |
| * @version $Revision$ $Date$ |
| * @author Rodney Waldhoff |
| */ |
| public final class BoundProcedure implements Procedure, Serializable { |
| /** |
| * @param procedure the procedure to adapt |
| * @param arg the constant argument to use |
| */ |
| public BoundProcedure(UnaryProcedure procedure, Object arg) { |
| this.procedure = procedure; |
| this.param = arg; |
| } |
| |
| public void run() { |
| procedure.run(param); |
| } |
| |
| public boolean equals(Object that) { |
| if(that instanceof BoundProcedure) { |
| return equals((BoundProcedure)that); |
| } else { |
| return false; |
| } |
| } |
| |
| public boolean equals(BoundProcedure that) { |
| return that == this || ( |
| (null != that) && |
| (null == procedure ? null == that.procedure : procedure.equals(that.procedure)) && |
| (null == param ? null == that.param : param.equals(that.param)) ); |
| |
| } |
| |
| public int hashCode() { |
| int hash = "BoundProcedure".hashCode(); |
| if(null != procedure) { |
| hash <<= 2; |
| hash ^= procedure.hashCode(); |
| } |
| if(null != param) { |
| hash <<= 2; |
| hash ^= param.hashCode(); |
| } |
| return hash; |
| } |
| |
| public String toString() { |
| return "BoundProcedure<" + procedure + "(" + param + ")>"; |
| } |
| |
| /** |
| * Adapt the given, possibly-<code>null</code>, |
| * {@link UnaryProcedure UnaryProcedure} to the |
| * {@link Procedure Procedure} interface by binding |
| * the specified <code>Object</code> as a constant |
| * argument. |
| * When the given <code>UnaryProcedure</code> is <code>null</code>, |
| * returns <code>null</code>. |
| * |
| * @param procedure the possibly-<code>null</code> |
| * {@link UnaryProcedure UnaryProcedure} to adapt |
| * @param arg the object to bind as a constant argument |
| * @return a <code>BoundProcedure</code> wrapping the given |
| * {@link UnaryProcedure UnaryProcedure}, or <code>null</code> |
| * if the given <code>UnaryProcedure</code> is <code>null</code> |
| */ |
| public static BoundProcedure bind(UnaryProcedure procedure, Object arg) { |
| return null == procedure ? null : new BoundProcedure(procedure,arg); |
| } |
| |
| /** The {@link UnaryProcedure UnaryProcedure} I'm wrapping. */ |
| private UnaryProcedure procedure = null; |
| /** The parameter to pass to that procedure. */ |
| private Object param = null; |
| } |