org.semanticweb.elk.owl.predefined.AbstractElkObject Maven / Gradle / Ivy
package org.semanticweb.elk.owl.predefined;
/*
* #%L
* ELK OWL Object Interfaces
* $Id:$
* $HeadURL:$
* %%
* Copyright (C) 2011 - 2016 Department of Computer Science, University of Oxford
* %%
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
* #L%
*/
import org.semanticweb.elk.owl.comparison.ElkObjectEquality;
import org.semanticweb.elk.owl.comparison.ElkObjectHash;
import org.semanticweb.elk.owl.interfaces.ElkObject;
import org.semanticweb.elk.owl.printers.OwlFunctionalStylePrinter;
/**
* A skeleton implementation of {@link ElkObject} defining equality, hash, and
* similar functions. All other implementation should extend or delegate to this
* class.
*
* @author Yevgeny Kazakov
*/
public abstract class AbstractElkObject implements ElkObject {
/**
* hash code, computed on demand
*/
private int hashCode_ = 0;
@Override
public final int hashCode() {
if (hashCode_ == 0) {
hashCode_ = accept(ElkObjectHash.getInstance());
}
// else
return hashCode_;
}
@Override
public final boolean equals(Object o) {
return this == o || (o != null && hashCode() == o.hashCode()
&& accept(new ElkObjectEquality(o)) != null);
}
@Override
public String toString() {
return OwlFunctionalStylePrinter.toString(this);
}
}