com.sander.verhagen.DatabaseConnectionHelper.java Source code

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Here is the source code for com.sander.verhagen.DatabaseConnectionHelper.java

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/**
 * Copyright 2012 Sander Verhagen
 * 
 * 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 com.sander.verhagen;

import java.io.File;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

import org.apache.commons.io.FileUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Some database-related helper functions.
 * 
 * @author Sander Verhagen
 */
public class DatabaseConnectionHelper {
    private static Logger log = LoggerFactory.getLogger(DatabaseConnectionHelper.class);

    private Connection connection;

    /**
     * Constructor.
     */
    public DatabaseConnectionHelper() {
        try {
            Class.forName("org.sqlite.JDBC");
        } catch (ClassNotFoundException exception) {
            throw new RuntimeException("Requires SQLite JDBC driver on classpath", exception);
        }
    }

    /**
     * Open the database connection.
     * 
     * @return database connection
     */
    public Connection open() {
        try {
            String url = determineDatabaseUrl();
            log.info("Determined database URL: {}", url);
            connection = DriverManager.getConnection(url);
            return connection;
        } catch (SQLException exception) {
            throw new RuntimeException("Problem opening database connection", exception);
        }
    }

    /**
     * Close the database connection.
     */
    public void close() {
        try {
            connection.close();
        } catch (SQLException exception) {
            throw new RuntimeException("Problem closing database connection", exception);
        }
    }

    /**
     * Determine the database URL. The trick here is to determine it without
     * asking the user to tell us their Skype name. Note that this is currently
     * working for Windows, it should be not too difficult to make it work for
     * other platforms, if anyone desires this. Note that this is currently only
     * supporting a single account for each system user, it should not be too
     * difficult to make it work for multiple users<br/>
     * <br/>
     * The file location of the database should be something like:
     * <code>C:\Users\&lt;Windows user&gt;\Application Data\Skype\&lt;Skype user&gt;\main.db</code>
     * 
     * @return database URL as determined
     */
    String determineDatabaseUrl() {
        File skypeFolder = getSkypeFolder();
        String[] extensions = { "db" };
        Collection<File> files = FileUtils.listFiles(skypeFolder, extensions, true);
        List<File> mainFiles = new ArrayList<File>();
        for (File file : files) {
            if (file.getName().equals("main.db")) {
                mainFiles.add(file);
            }
        }

        switch (mainFiles.size()) {
        case 0:
            throw new RuntimeException("No database file found. Looked here: " + skypeFolder);
        case 1:
            return "jdbc:sqlite:" + mainFiles.get(0).getAbsolutePath();
        default:
            throw new RuntimeException("Multiple database files found; " + "don't know which one to choose");
        }
    }

    File getSkypeFolder() {
        File applicationData = getApplicationDataFolder();
        File skypeFolder = new File(applicationData, "Skype");
        if (!skypeFolder.exists()) {
            throw new RuntimeException(
                    "Skype application data not found. Maybe no Skype installed. Looked here: " + skypeFolder);
        }
        return skypeFolder;
    }

    File getApplicationDataFolder() {
        String applicationData = System.getenv("APPDATA");
        if (applicationData == null) {
            String userHome = System.getProperty("user.home");
            applicationData = userHome + "\\Application Data";
        }
        return new File(applicationData);
    }
}