org.nuclos.common.collect.collectable.searchcondition.CollectableComparisonWithOtherField.java Source code

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Here is the source code for org.nuclos.common.collect.collectable.searchcondition.CollectableComparisonWithOtherField.java

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//Copyright (C) 2010  Novabit Informationssysteme GmbH
//
//This file is part of Nuclos.
//
//Nuclos is free software: you can redistribute it and/or modify
//it under the terms of the GNU Affero General Public License as published by
//the Free Software Foundation, either version 3 of the License, or
//(at your option) any later version.
//
//Nuclos is distributed in the hope that it will be useful,
//but WITHOUT ANY WARRANTY; without even the implied warranty of
//MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//GNU Affero General Public License for more details.
//
//You should have received a copy of the GNU Affero General Public License
//along with Nuclos.  If not, see <http://www.gnu.org/licenses/>.
package org.nuclos.common.collect.collectable.searchcondition;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;

import org.apache.commons.lang.NullArgumentException;

import org.nuclos.common.collect.collectable.CollectableEntityField;
import org.nuclos.common.collect.collectable.DefaultCollectableEntityField;
import org.nuclos.common.collect.collectable.searchcondition.visit.AtomicVisitor;

/**
 * A comparison with another field as a <code>CollectableSearchCondition</code>.
 * Has two operands: a field (left side) and a comparand field (right side, the field to compare with).
 * <br>
 * <br>Created by Novabit Informationssysteme GmbH
 * <br>Please visit <a href="http://www.novabit.de">www.novabit.de</a>
 *
 * @author   <a href="mailto:Christoph.Radig@novabit.de">Christoph.Radig</a>
 * @version   01.00.00
 */
public final class CollectableComparisonWithOtherField extends AtomicCollectableSearchCondition {

    /**
     * @invariant clctefOther != null
     * 
     * @deprecated Why is this transient? How is a value after serialization enforced?
     */
    private transient CollectableEntityField clctefOther;

    /**
     * @param clctef
     * @param compop
     * @param clctefOther
     * @precondition compop.getOperandCount() == 2
     * @precondition clctefOther != null
     * @precondition clctefOther.getJavaClass() == clctef.getJavaClass()
     * @postcondition this.getComparisonOperator().equals(compop)
     * @postcondition this.getOtherField().equals(clctefOther)
     */
    public CollectableComparisonWithOtherField(CollectableEntityField clctef, ComparisonOperator compop,
            CollectableEntityField clctefOther) {

        super(clctef, compop);

        if (compop.getOperandCount() != 2) {
            throw new IllegalArgumentException("compop: " + compop);
        }
        if (clctefOther == null) {
            throw new NullArgumentException("clctefOther");
        }
        if (clctefOther.getJavaClass() != clctef.getJavaClass()) {
            throw new IllegalArgumentException("datatypes don't match - cannot compare "
                    + clctefOther.getJavaClass().getName() + " with " + clctef.getJavaClass().getName());
        }

        this.clctefOther = clctefOther;

        assert this.getComparisonOperator().equals(compop);
        assert this.getOtherField().equals(clctefOther);
    }

    /**
     * @return the field to compare with (the right side of the comparison).
     * @postcondition result != null
     */
    public CollectableEntityField getOtherField() {
        return this.clctefOther;
    }

    /**
     * @return <code>null</code>. The result is used to be displayed in text fields, and we don't want to see the entity field there.
     */
    @Override
    public String getComparandAsString() {
        return null;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (!(o instanceof CollectableComparisonWithOtherField)) {
            return false;
        }
        final CollectableComparisonWithOtherField that = (CollectableComparisonWithOtherField) o;

        return super.equals(that) && this.clctefOther.equals(that.clctefOther);
    }

    @Override
    public int hashCode() {
        return super.hashCode() ^ this.clctefOther.hashCode();
    }

    @Override
    public <O, Ex extends Exception> O accept(AtomicVisitor<O, Ex> visitor) throws Ex {
        return visitor.visitComparisonWithOtherField(this);
    }

    private void writeObject(ObjectOutputStream oos) throws IOException {
        oos.defaultWriteObject();
        // CollectableEntityField generally is not serializable, but DefaultCollectableEntityField is:
        oos.writeObject(new DefaultCollectableEntityField(clctefOther, clctefOther.getEntityName()));
    }

    private void readObject(ObjectInputStream ois) throws IOException, ClassNotFoundException {
        ois.defaultReadObject();
        // CollectableEntityField is not serializable:
        this.clctefOther = (CollectableEntityField) ois.readObject();
    }

    @Override
    public String toString() {
        return getClass().getName() + ":" + getConditionName() + ":" + getComparisonOperator() + ":"
                + getEntityField() + ":" + clctefOther;
    }

} // class CollectableComparisonWithField