code: package it.unibz.inf.ontop.protege.action;
  
  /*
   * #%L
   * ontop-protege
   * %%
   * Copyright (C) 2009 - 2013 KRDB Research Centre. Free University of Bozen Bolzano.
   * %%
   * 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 it.unibz.inf.ontop.protege.core.OBDAEditorKitSynchronizerPlugin;
  import it.unibz.inf.ontop.protege.core.OBDAModel;
  import it.unibz.inf.ontop.protege.mapping.TriplesMap;
  import it.unibz.inf.ontop.protege.utils.DialogUtils;
  import it.unibz.inf.ontop.protege.utils.OntopAbstractAction;
  import org.protege.editor.core.ui.action.ProtegeAction;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import javax.swing.*;
  import javax.swing.table.DefaultTableModel;
  import java.awt.*;
  import java.awt.event.ActionEvent;
  import java.awt.event.WindowAdapter;
  import java.awt.event.WindowEvent;
  import java.sql.Connection;
  import java.sql.ResultSet;
  import java.sql.Statement;
  import java.util.concurrent.CancellationException;
  import java.util.concurrent.ExecutionException;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  import static it.unibz.inf.ontop.protege.utils.DialogUtils.*;
  
  public class MappingStatisticsAction extends ProtegeAction {
  
  	private static final long serialVersionUID = 3322509244957306932L;
  
  	private static final Logger LOGGER = LoggerFactory.getLogger(MappingStatisticsAction.class);
  
  	private static final String DIALOG_TITLE = "Mapping Statistics";
  
  	private static final int ERROR_ENTRY = -1;
  
  	private static final class TriplesMapInfo {
  		private final String id;
  		private final int count;
  
  		TriplesMapInfo(String id, int count) {
  			this.id = id;
  			this.count = count;
  		}
  
  		boolean isValid() { return count != ERROR_ENTRY; }
  
  		Object[] asRow() {
  			return new Object[] { id, isValid() ? count : "<html><i>error</i></html>" };
  		}
  	}
  
  	@Override
  	public void actionPerformed(ActionEvent actionEvent) {
  		JDialog dialog = new JDialog((Frame)null, DIALOG_TITLE, true);
  
  		JPanel statisticsPanel = new JPanel(new BorderLayout());
  		JPanel summaryPanel = new JPanel(new FlowLayout(FlowLayout.LEFT));
  		summaryPanel.add(new JLabel("<html><b>Total number of triples:</b></html>"));
  		JLabel summaryLabel = new JLabel("<html><i>retrieving...</i></html>");
  		summaryPanel.add(summaryLabel);
  		statisticsPanel.add(summaryPanel, BorderLayout.NORTH);
  
  		String[] columnNames = {"Mapping ID", "Triples"};
  		DefaultTableModel tableModel = DialogUtils.createNonEditableTableModel(columnNames);
  
  		JTable triplesCountTable = new JTable(tableModel);
  		triplesCountTable.getColumnModel().getColumn(0).setPreferredWidth(400);
  		triplesCountTable.getColumnModel().getColumn(1).setMaxWidth(100);
  		statisticsPanel.add(new JScrollPane(triplesCountTable), BorderLayout.CENTER);
  
  		OBDAModel obdaModel = OBDAEditorKitSynchronizerPlugin.getCurrentOBDAModel(getEditorKit());
  		SwingWorker<Integer, TriplesMapInfo> worker = new SwingWorker<Integer, TriplesMapInfo>() {
  
  			@Override
  			protected Integer doInBackground() throws Exception {
  				try (Connection c = obdaModel.getDataSource().getConnection();
  					 Statement st = c.createStatement()) {
  					int total = 0;
  					for (TriplesMap map : obdaModel.getTriplesMapManager()) {
  						if (isCancelled())
  							break;
  
  						TriplesMapInfo info = retrieveInfo(map, st);
  						if (info.isValid() && total != ERROR_ENTRY)
  							total += info.count;
  						else
  							total = ERROR_ENTRY;
  
  						publish(info);
  					}
  					return total;
  				}
  			}
  
  			@Override
  			protected void process(java.util.List<TriplesMapInfo> list) {
  				for (TriplesMapInfo info : list)
  					tableModel.addRow(info.asRow());
  			}
  
  			@Override
  			protected void done() {
  				try {
  					int count = get();
  					summaryLabel.setText(count != ERROR_ENTRY
  						? "<html><b>" + count + "</b></html>"
  						: "An error occurred in the counting process.");
  				}
  				catch (CancellationException e) {
  					/* NO-OP */
  				}
  				catch (InterruptedException e) {
  					summaryLabel.setText("An error occurred: " + e.getMessage());
  				}
  				catch (ExecutionException e) {
  					dialog.dispose();
  					DialogUtils.showErrorDialog(getWorkspace(), DIALOG_TITLE, DIALOG_TITLE + "error.", LOGGER, e, obdaModel.getDataSource());
  				}
  			}
  		};
  		worker.execute();
  
  		JPanel commandPanel = new JPanel(new FlowLayout());
  
  		OntopAbstractAction closeAction = getStandardCloseWindowAction("Close", dialog);
  		JButton closeButton = getButton(closeAction);
  		commandPanel.add(closeButton);
  
  		setUpAccelerator(dialog.getRootPane(), closeAction);
  		dialog.getRootPane().setDefaultButton(closeButton);
  		dialog.addWindowListener(new WindowAdapter() {
  			@Override
  			public void windowClosing(WindowEvent e) {
  				worker.cancel(false);
  			}
  		});
  
  		dialog.setLayout(new BorderLayout());
  		dialog.add(statisticsPanel, BorderLayout.CENTER);
  		dialog.add(commandPanel, BorderLayout.SOUTH);
  
  		dialog.setPreferredSize(new Dimension(520, 400));
  		DialogUtils.setLocationRelativeToProtegeAndOpen(getEditorKit(), dialog);
  	}
  
  	private static TriplesMapInfo retrieveInfo(TriplesMap triplesMap, Statement st) {
  		try {
  			String sql = getSelectionString(triplesMap.getSqlQuery());
  			try (ResultSet rs = st.executeQuery(sql)) {
  				int count = 0;
  				while (rs.next()) {
  					count = rs.getInt(1);
  				}
  				return new TriplesMapInfo(triplesMap.getId(), count * triplesMap.getTargetAtoms().size());
  			}
  		}
  		catch (Exception e) {
  			LOGGER.error("Exception while computing mapping statistics", e);
  			return new TriplesMapInfo(triplesMap.getId(), ERROR_ENTRY);
  		}
  	}
  
  	private static String getSelectionString(String originalSql) throws Exception {
  		String sql = originalSql.toLowerCase(); // make it lower case to help identify a string.
  		Matcher m = Pattern.compile("[\\n\\s\\t]*from[\\n\\s\\t]*").matcher(sql);
  		if (m.find()) {
  			int start = m.start();
  			return "select COUNT(*) " + originalSql.substring(start);
  		}
  		throw new Exception("Could not find the \"FROM\" keyword in the source query\n" + originalSql);
  	}
  
  	@Override
  	public void initialise()  { /* NO-OP */}
  
  	@Override
  	public void dispose() { /* NO-OP */ }
  
  }
  