com.phoenixst.collections.AllPredicate.java Source code

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

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/*
 *  $Id: AllPredicate.java,v 1.12 2006/06/07 22:27:37 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.*;

import org.apache.commons.collections.Predicate;

/**
 *  A <code>Predicate</code> which returns the logical short-circuit
 *  <em>and</em> of its operands.
 *
 *  <P>This is mostly equivalent to the class of the same name in
 *  Jakarta Commons-Collections 3.0.  The deserialization process
 *  in this version checks for null fields.  No equivalent exists
 *  in version 2.1.
 *
 *  @version    $Revision: 1.12 $
 *  @author     Ray A. Conner
 *
 *  @since      1.0
 */
public final class AllPredicate implements Predicate, Serializable {

    private static final long serialVersionUID = 2L;

    /**
     *  The array of <code>Predicates</code>.
     *
     *  @serial
     */
    private final Predicate[] predicateArray;

    ////////////////////////////////////////
    // Constructors
    ////////////////////////////////////////

    /**
     *  Creates a new <code>AllPredicate</code>.
     */
    public AllPredicate(Predicate[] predicates) {
        super();
        predicateArray = predicates.clone();
        if (containsNull(predicateArray)) {
            throw new IllegalArgumentException("Predicate array has a null element.");
        }
    }

    /**
     *  Creates a new <code>AllPredicate</code>.
     */
    public AllPredicate(Collection predicates) {
        super();
        Predicate[] temp = new Predicate[predicates.size()];
        predicateArray = (Predicate[]) predicates.toArray(temp);
        if (containsNull(predicateArray)) {
            throw new IllegalArgumentException("Collection argument has a null element.");
        }
    }

    ////////////////////////////////////////
    // Serialization and construction assistance methods
    ////////////////////////////////////////

    private static boolean containsNull(Object[] array) {
        for (int i = array.length - 1; i >= 0; i--) {
            if (array[i] == null) {
                return true;
            }
        }
        return false;
    }

    private void readObject(ObjectInputStream in) throws ClassNotFoundException, IOException {
        in.defaultReadObject();
        if (predicateArray == null) {
            throw new InvalidObjectException("Predicate array is null.");
        }
        if (containsNull(predicateArray)) {
            throw new InvalidObjectException("Predicate array has a null element.");
        }
    }

    ////////////////////////////////////////
    // Predicate
    ////////////////////////////////////////

    public boolean evaluate(Object object) {
        for (int i = 0; i < predicateArray.length; i++) {
            if (!predicateArray[i].evaluate(object)) {
                return false;
            }
        }
        return true;
    }

    ////////////////////////////////////////
    // Other methods
    ////////////////////////////////////////

    /**
     *  Returns an unmodifiable <code>List</code> of the argument
     *  <code>Predicates</code> being used by this
     *  <code>AllPredicate</code>.
     */
    public List getOperands() {
        return Collections.unmodifiableList(Arrays.asList(predicateArray));
    }

    public boolean equals(Object object) {
        if (object == this) {
            return true;
        }
        if (!(object instanceof AllPredicate)) {
            return false;
        }
        AllPredicate pred = (AllPredicate) object;
        return Arrays.equals(predicateArray, pred.predicateArray);
    }

    public int hashCode() {
        return Arrays.hashCode(predicateArray);
    }

    public String toString() {
        StringBuilder s = new StringBuilder();
        s.append("(ALL ");
        s.append(Arrays.toString(predicateArray));
        s.append(")");
        return s.toString();
    }

}