org.eclipse.rdf4j.model.Statement Maven / Gradle / Ivy
/*******************************************************************************
* Copyright (c) 2015 Eclipse RDF4J contributors, Aduna, and others.
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Distribution License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* SPDX-License-Identifier: BSD-3-Clause
*******************************************************************************/
package org.eclipse.rdf4j.model;
import java.io.Serializable;
/**
* An RDF statement, with optional associated context. A statement can have an associated context in specific cases, for
* example when fetched from a repository.
*
* Additional utility functionality for working with {@code Statement} objects is available in the
* {@code org.eclipse.rdf4j.model.util.Statements} utility class.
*
* @implNote In order to ensure interoperability of concrete classes implementing this interface,
* {@link #equals(Object)} and {@link #hashCode()} methods must be implemented exactly as described in their
* specs.
*/
public interface Statement extends Serializable {
/**
* Gets the subject of this statement.
*
* @return The statement's subject.
*/
Resource getSubject();
/**
* Gets the predicate of this statement.
*
* @return The statement's predicate.
*/
IRI getPredicate();
/**
* Gets the object of this statement.
*
* @return The statement's object.
*/
Value getObject();
/**
* Gets the context of this statement.
*
* @return The statement's context, or null in case of the null context or if not applicable.
*/
Resource getContext();
/**
* Compares this statement to another object.
*
* @param other the object to compare this statement to
* @return {@code true} if the other object is an instance of {@code Statement} and if their
* {@linkplain #getSubject() subjects}, {@linkplain #getPredicate() predicates}, {@linkplain #getObject()
* objects} and {@linkplain #getContext() contexts} are equal; {@code false} otherwise
*/
@Override
boolean equals(Object other);
/**
* Computes the hash code of this statement.
*
* @return a hash code for this statement computed as {@link java.util.Objects#hash Objects.hash}(
* {@link #getSubject()}, {@link #getPredicate()}, {@link #getObject()}, {@link #getContext()})
*/
@Override
int hashCode();
}