edu.cornell.mannlib.vitro.webapp.servlet.setup.AssembleModelsSetup.java Source code

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Here is the source code for edu.cornell.mannlib.vitro.webapp.servlet.setup.AssembleModelsSetup.java

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/* $This file is distributed under the terms of the license in /doc/license.txt$ */

package edu.cornell.mannlib.vitro.webapp.servlet.setup;

import java.io.InputStream;
import java.util.LinkedList;
import java.util.List;
import java.util.Set;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import com.hp.hpl.jena.assembler.Assembler;
import com.hp.hpl.jena.ontology.OntModel;
import com.hp.hpl.jena.rdf.model.Model;
import com.hp.hpl.jena.rdf.model.ModelFactory;
import com.hp.hpl.jena.rdf.model.Resource;
import com.hp.hpl.jena.rdf.model.ResourceFactory;
import com.hp.hpl.jena.util.iterator.ExtendedIterator;
import com.hp.hpl.jena.vocabulary.RDF;

import edu.cornell.mannlib.vitro.webapp.dao.jena.ModelSynchronizer;

/**
 * This is the beginning of a more sane and flexible model management system,
 * especially necessary for DataStaR.
 * Don't use it yet; it's going to change.
 * (That part is still insane, I know.)
 * @author bjl23
 */
public class AssembleModelsSetup implements ServletContextListener {

    private static final Log log = LogFactory.getLog(AssembleModelsSetup.class);

    private List<Model> assembledModels = new LinkedList<Model>();

    private String ASSEMBLERS_DIR_PATH = "/WEB-INF/assemblers/";
    private Resource ASSEMBLER_OBJECT = ResourceFactory
            .createProperty("http://jena.hpl.hp.com/2005/11/Assembler#Object");
    private String SYNTAX = "N3";

    public void contextInitialized(ServletContextEvent sce) {

        OntModel jenaOntModel = null;
        try {
            jenaOntModel = (OntModel) sce.getServletContext().getAttribute("baseOntModel");
        } catch (Exception e) {
            log.error("No baseOntModel found to which to attach assembled models");
            return;
        }
        // read assemblers out of assemblers directory
        Set pathSet = sce.getServletContext().getResourcePaths(ASSEMBLERS_DIR_PATH);
        for (String path : (Set<String>) pathSet) {
            InputStream assemblerInputStream = sce.getServletContext().getResourceAsStream(path);
            Model assemblerModel = ModelFactory.createDefaultModel();
            try {
                assemblerModel.read(assemblerInputStream, null, SYNTAX);
                ExtendedIterator assemblerIt = assemblerModel.listResourcesWithProperty(RDF.type, ASSEMBLER_OBJECT);
                while (assemblerIt.hasNext()) {
                    Resource assemblerObj = (Resource) assemblerIt.next();
                    Model assembledModel = Assembler.general.openModel(assemblerObj);
                    /* special stuff here */
                    Model memModel = ModelFactory.createDefaultModel();
                    memModel.add(assembledModel);
                    memModel.register(new ModelSynchronizer(assembledModel));
                    /* end special stuff */
                    if (assembledModel != null) {
                        jenaOntModel.addSubModel(memModel);
                    }
                }
                if (assemblerIt != null) {
                    assemblerIt.close();
                }
            } catch (Exception e) {
                log.error("Unable to use assembler at " + path);
            }
        }
        System.out.println("ContextListener AssembleModelsSetup done");
    }

    public void contextDestroyed(ServletContextEvent sce) {
        for (Model model : assembledModels) {
            if (model != null) {
                model.close();
            }
        }
    }

}