SortingRDFHandler.java
- /*
- * *********************************************************************************************************************
- *
- * blueMarine II: Semantic Media Centre
- * http://tidalwave.it/projects/bluemarine2
- *
- * Copyright (C) 2015 - 2021 by Tidalwave s.a.s. (http://tidalwave.it)
- *
- * *********************************************************************************************************************
- *
- * 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.
- *
- * *********************************************************************************************************************
- *
- * git clone https://bitbucket.org/tidalwave/bluemarine2-src
- * git clone https://github.com/tidalwave-it/bluemarine2-src
- *
- * *********************************************************************************************************************
- */
- package it.tidalwave.bluemarine2.util;
- import javax.annotation.Nonnull;
- import java.util.ArrayList;
- import java.util.List;
- import lombok.experimental.Delegate;
- import lombok.RequiredArgsConstructor;
- import org.eclipse.rdf4j.model.Statement;
- import org.eclipse.rdf4j.model.vocabulary.RDF;
- import org.eclipse.rdf4j.rio.RDFHandler;
- import org.eclipse.rdf4j.rio.RDFHandlerException;
- /***********************************************************************************************************************
- *
- * @author Fabrizio Giudici
- *
- **********************************************************************************************************************/
- @RequiredArgsConstructor
- public class SortingRDFHandler implements RDFHandler
- {
- interface Exclusions
- {
- public void handleStatement (Statement statement)
- throws RDFHandlerException;
- public void endRDF()
- throws RDFHandlerException;
- }
- @Nonnull @Delegate(excludes = Exclusions.class)
- private final RDFHandler delegate;
- private final List<Statement> statements = new ArrayList<>();
- @Override
- public void handleStatement (@Nonnull final Statement statement)
- throws RDFHandlerException
- {
- statements.add(statement);
- }
- @Override
- public void endRDF()
- throws RDFHandlerException
- {
- statements.sort((st1, st2) ->
- {
- final String s1 = st1.getSubject().stringValue();
- final String s2 = st2.getSubject().stringValue();
- final int c1 = s1.compareTo(s2);
- if (c1 != 0)
- {
- return c1;
- }
- final String p1 = st1.getPredicate().stringValue();
- final String p2 = st2.getPredicate().stringValue();
- final int c2 = p1.compareTo(p2);
- if (c2 != 0)
- {
- if (p1.equals(RDF.TYPE.stringValue()))
- {
- return -1;
- }
- else if (p2.equals(RDF.TYPE.stringValue()))
- {
- return +1;
- }
- return c2;
- }
- final String o1 = st1.getObject().stringValue();
- final String o2 = st2.getObject().stringValue();
- return o1.compareTo(o2);
- });
- for (final Statement statement : statements)
- {
- delegate.handleStatement(statement);
- }
- delegate.endRDF();
- }
- }