org.opengis.filter.ExcludeFilter Maven / Gradle / Ivy

/*
 *    GeoTools - The Open Source Java GIS Toolkit
 *    http://geotools.org
 *
 *    (C) 2011, Open Source Geospatial Foundation (OSGeo)
 *    (C) 2005 Open Geospatial Consortium Inc.
 *
 *    All Rights Reserved. http://www.opengis.org/legal/
 */
package org.opengis.filter;

import java.io.ObjectStreamException;
import java.io.Serializable;

/**
 * Indicating "filter all", evaluates to {@code false}. This is a placeholder filter intended to be
 * used in data structuring definition.
 *
 * 
 *
 * 

 *   EXCLUDE or Filter ==> Filter
 *   
EXCLUDE and Filter ==> EXCLUDE
 *   
EXCLUDE ==> INCLUDE
 * 
 *
 * The above does imply that the AND opperator can short circuit on encountering ALL.
 *
 * @author Jody Garnett (Refractions Research, Inc.)
 * @author Martin Desruisseaux (Geomatys)
 */
public final class ExcludeFilter implements Filter, Serializable {
    /** For cross-version compatibility. */
    private static final long serialVersionUID = -716705962006999508L;

    /** Not extensible. */
    ExcludeFilter() {}

    /** Accepts a visitor. */
    public Object accept(FilterVisitor visitor, Object extraData) {
        return visitor.visit(this, extraData);
    }

    /** Returns {@code false}, content is excluded. */
    public boolean evaluate(Object object) {
        return false;
    }

    /** Returns a string representation of this filter. */
    @Override
    public String toString() {
        return "Filter.EXCLUDE";
    }

    /** Returns the canonical instance on deserialization. */
    private Object readResolve() throws ObjectStreamException {
        return Filter.EXCLUDE;
    }
}