eu.lod2.EURL.java Source code

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Here is the source code for eu.lod2.EURL.java

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/*
* Copyright 2011 LOD2 consortium
*
* 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.
*/
package eu.lod2;

import com.vaadin.ui.*;
import com.vaadin.ui.Button.ClickEvent;
import com.vaadin.ui.Button.ClickListener;
import org.openrdf.model.Resource;
import org.openrdf.repository.RepositoryConnection;
import org.openrdf.repository.RepositoryException;
import org.openrdf.rio.RDFFormat;
import org.openrdf.rio.RDFParseException;

import java.io.*;
import java.net.*;

/**
 * Extract and upload the RDF content of a URL in a graph.
 */
//@SuppressWarnings("serial")
public class EURL extends CustomComponent {

    // reference to the global internal state
    private LOD2DemoState state;

    private ExportSelector exportGraph;
    private TextField uriSelector;
    private Label resultUser;

    public EURL(LOD2DemoState st) {

        // The internal state
        state = st;

        VerticalLayout panel = new VerticalLayout();
        Label description = new Label("Import the RDF available at a URL");
        panel.addComponent(description);

        exportGraph = new ExportSelector(state);
        exportGraph.setDebugId(this.getClass().getSimpleName() + "_exportGraph");
        panel.addComponent(exportGraph);

        uriSelector = new TextField("Enter URL to extract from: ");
        uriSelector.setDebugId(this.getClass().getSimpleName() + "_uriSelector");
        uriSelector.setDescription(
                "From this URL the RDF will be extracted and imported in the above selected graph.");
        panel.addComponent(uriSelector);

        Button importURL = new Button("Extract Links", new ClickListener() {
            public void buttonClick(ClickEvent event) {
                doImportURL();
            }

            ;
        });
        importURL.setDebugId(this.getClass().getSimpleName() + "_importURL");
        importURL.setEnabled(true);
        importURL.setDescription("The operation is active only if the exported graph has been selected.");
        panel.addComponent(importURL);

        resultUser = new Label("");
        panel.addComponent(resultUser);

        /*
            // if an uri is given 
            if (!uriSelector.getValue().equals("")) {
                // activate button
                importURL.setEnabled(true);
            };
        */

        // The composition root MUST be set
        setCompositionRoot(panel);
    }

    // propagate the information of one tab to another.
    public void setDefaults() {
    }

    ;

    // execute the linking
    public void doImportURL() {
        try {
            String encoded = URLEncoder.encode((String) uriSelector.getValue(), "UTF-8");
            java.net.URL sameAsData = new java.net.URL(encoded);
            String baseURI = "http://localhost:8080/base#";

            RepositoryConnection con = state.getRdfStore().getConnection();
            Resource contextURI = con.getValueFactory().createURI(exportGraph.getExportGraph());
            Resource[] contexts = new Resource[] { contextURI };
            Long BeforeSize = con.size(contextURI);
            con.add(sameAsData, baseURI, RDFFormat.RDFXML, contexts);

            Long AddTriples = con.size(contextURI) - BeforeSize;

            if (AddTriples == 0) {
                resultUser.setValue("No triples added to target store.");
            } else {
                resultUser.setValue("Added " + AddTriples.toString() + " triples to target store.");
            }
            ;

        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (RepositoryException e) {
            e.printStackTrace();
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (RDFParseException e) {
            e.printStackTrace();
        }
        ;
    }

    ;

};