CompoundFilter.java

/*******************************************************************************
 * Copyright (c) 1998, 2015 Oracle and/or its affiliates. All rights reserved.
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
 * which accompanies this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *     Oracle - initial API and implementation from Oracle TopLink
******************************************************************************/
package org.eclipse.persistence.tools.workbench.utility.filters;

import java.io.Serializable;

import org.eclipse.persistence.tools.workbench.utility.string.StringTools;


/**
 * This filter provides a simple framework for combining the behavior
 * of a pair of filters.
 */
public abstract class CompoundFilter
    implements Filter, Cloneable, Serializable
{
    protected Filter filter1;
    protected Filter filter2;

    private static final long serialVersionUID = 1L;


    /**
     * Construct a filter that will "accept" any object that is accept by both
     * of the specified wrapped filters.
     */
    public CompoundFilter(Filter filter1, Filter filter2) {
        super();
        if ((filter1 == null) || (filter2 == null)) {
            throw new NullPointerException();
        }
        this.filter1 = filter1;
        this.filter2 = filter2;
    }

    /**
     * Return filter1.
     */
    public Filter getFilter1() {
        return this.filter1;
    }

    /**
     * Return filter2.
     */
    public Filter getFilter2() {
        return this.filter2;
    }

    /**
     * @see Object#clone()
     */
    public Object clone() {
        try {
            return super.clone();
        } catch (CloneNotSupportedException ex) {
            throw new InternalError();
        }
    }

    /**
     * @see Object#equals(Object)
     */
    public boolean equals(Object o) {
        if ( ! (o instanceof CompoundFilter)) {
            return false;
        }
        CompoundFilter other = (CompoundFilter) o;
        return (this.filter1.equals(other.filter1) && this.filter2.equals(other.filter2)) ||
                (this.filter1.equals(other.filter2) && this.filter2.equals(other.filter1));
    }

    /**
     * @see Object#hashCode()
     */
    public int hashCode() {
        return this.filter1.hashCode() ^ this.filter2.hashCode();
    }

    /**
     * @see Object#toString()
     */
    public String toString() {
        return StringTools.buildToStringFor(this, this.filter1 + " " + this.operatorString() + " " + this.filter2);
    }

    /**
     * Return a string representation of the filter's operator.
     */
    protected abstract String operatorString();

}