com.phoenixst.collections.ContainsPredicate.java Source code

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Here is the source code for com.phoenixst.collections.ContainsPredicate.java

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/*
 *  $Id: ContainsPredicate.java,v 1.2 2006/06/07 16:33:29 rconner Exp $
 *
 *  Copyright (C) 1994-2006 by Phoenix Software Technologists,
 *  Inc. and others.  All rights reserved.
 *
 *  THIS PROGRAM AND DOCUMENTATION IS PROVIDED UNDER THE TERMS OF THE
 *  COMMON PUBLIC LICENSE ("AGREEMENT") WHICH ACCOMPANIES IT.  ANY
 *  USE, REPRODUCTION OR DISTRIBUTION OF THE PROGRAM CONSTITUTES
 *  RECIPIENT'S ACCEPTANCE OF THE AGREEMENT.
 *
 *  The license text can also be found at
 *    http://opensource.org/licenses/cpl.php
 */

package com.phoenixst.collections;

import java.io.*;
import java.util.Collection;

import org.apache.commons.collections.Predicate;

/**
 *  A <code>Predicate</code> which tests whether an object is an
 *  element of a <code>Collection</code>.
 *
 *  @version    $Revision: 1.2 $
 *  @author     Ray A. Conner
 *
 *  @since      1.0
 */
public final class ContainsPredicate implements Predicate, Serializable {

    private static final long serialVersionUID = 1L;

    /**
     *  The collection in which to test for membership.
     *
     *  @serial
     */
    private final Collection collection;

    /**
     *  Creates a new <code>ContainsPredicate</code>.
     *  <strong>Note:</strong> This class does not copy the
     *  constructor argument, so be careful not to alter it after
     *  creating this <code>ContainsPredicate</code>.
     */
    public ContainsPredicate(Collection collection) {
        super();
        this.collection = collection;
        if (collection == null) {
            throw new IllegalArgumentException("Argument Collection is null.");
        }
    }

    private void readObject(ObjectInputStream in) throws ClassNotFoundException, IOException {
        in.defaultReadObject();
        if (collection == null) {
            throw new InvalidObjectException("Collection is null.");
        }
    }

    public boolean evaluate(Object object) {
        return collection.contains(object);
    }

    /**
     *  Returns the <code>Collection</code> being used by this
     *  <code>ContainsPredicate</code>.
     */
    public Collection getCollection() {
        return collection;
    }

    public boolean equals(Object object) {
        if (object == this) {
            return true;
        }
        if (!(object instanceof ContainsPredicate)) {
            return false;
        }
        ContainsPredicate pred = (ContainsPredicate) object;
        return collection.equals(pred.collection);
    }

    public int hashCode() {
        return collection.hashCode();
    }

    public String toString() {
        StringBuilder s = new StringBuilder(getClass().getSimpleName());
        s.append(collection);
        return s.toString();
    }

}