it.unibz.inf.xmlssd.metadator.sqlite.SQLiteManager.java Source code

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Here is the source code for it.unibz.inf.xmlssd.metadator.sqlite.SQLiteManager.java

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/*
 * Copyright 2009 Martin Palma
 * 
 * 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 it.unibz.inf.xmlssd.metadator.sqlite;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Iterator;
import java.util.List;

import org.dom4j.Document;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;

/**
 * Class for interfacing the SQLite database.
 * @author Martin Palma <martin@palma.bz>
 *
 */
public class SQLiteManager {
    /** Logger **/
    private static org.apache.log4j.Logger log = org.apache.log4j.Logger.getLogger(SQLiteManager.class);

    private Connection aConnection;

    /**
     * Constructs the object.
     */
    public SQLiteManager() {
        try {
            Class.forName("org.sqlite.JDBC");
            // Establish connection
            aConnection = DriverManager.getConnection("jdbc:sqlite:" + System.getProperty("metadator.db"));

            // Create the Database Schema
            createSchema();
        } catch (ClassNotFoundException e) {
            log.fatal("Class Not Found: " + e.getMessage());
        } catch (SQLException e) {
            log.error("SQL Error: " + e.getMessage());
        }
    }

    /**
     * Method which parses the given XML documents and inserts it's data 
     * into the Database.
     * @param doc
     */
    public void put(Document doc) {
        List list = doc.selectNodes("//metadator/*");
        for (Iterator i = list.iterator(); i.hasNext();) {
            Element element = (Element) i.next();

            try {
                Camera camera = new Camera(aConnection);
                int camera_id = camera.put(element);

                element.addAttribute("camera_id", Integer.toString(camera_id));
                Photo photo = new Photo(aConnection);
                photo.put(element);
            } catch (SQLException e) {
                log.error("SQL Error: " + e.getMessage());
            }
        }
    }

    /**
     * Method which delete the item with the given id from the database.
     * @param id
     * @return
     */
    public Boolean delete(int id) {
        try {
            Photo photo = new Photo(aConnection);
            if (photo.delete(id) == 1)
                return true;
        } catch (SQLException e) {
            log.error("SQL Error: " + e.getMessage());
        }

        return false;
    }

    /**
     * Method which constructs a XML document from the data stored in the 
     * Database.
     * @return
     */
    public Document get() {
        Document document = DocumentHelper.createDocument();

        try {
            Photo photo = new Photo(aConnection);
            document = photo.get();
        } catch (SQLException e) {
            log.error("SQL Error in getting XML: " + e.getMessage());
        }

        return document;
    }

    /**
     * Method which creates the DB schema.
     * @throws SQLException
     */
    private void createSchema() {
        try {
            Statement stmt = aConnection.createStatement();

            stmt.executeUpdate(Photo.CREATE);
            stmt.executeUpdate(Camera.CREATE);

            stmt.close();
        } catch (SQLException e) {
            log.fatal("Could not create Database schema:" + e.getMessage());
        }
    }
}