org.lucane.server.database.DatabaseAbstractionLayer.java Source code

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Here is the source code for org.lucane.server.database.DatabaseAbstractionLayer.java

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/*
 * Lucane - a collaborative platform
 * Copyright (C) 2003  Vincent Fiack <vfiack@mail15.com>
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
package org.lucane.server.database;

import org.lucane.common.Logging;
import org.lucane.server.ServerConfig;
import org.lucane.server.database.xml.*;

import java.lang.reflect.*;
import java.sql.*;

import org.apache.commons.dbcp.BasicDataSource;
import javax.sql.DataSource;

/**
 * Database abstraction layer.
 * Allow to use different databases, even if the SQL types aren't completely normalized
 */
public abstract class DatabaseAbstractionLayer {
    /**
     * DatabaseLayer Factory
     * Get the layer corresponding to the driver
     */
    public static DatabaseAbstractionLayer createLayer(ServerConfig config) throws Exception {
        Class.forName(config.getDbDriver());

        BasicDataSource ds = new BasicDataSource();
        ds.setDriverClassName(config.getDbDriver());
        ds.setUsername(config.getDbLogin());
        ds.setPassword(config.getDbPassword());
        ds.setUrl(config.getDbUrl());

        ds.setPoolPreparedStatements(true);
        ds.setInitialSize(config.getDbPoolInitialSize());
        ds.setMaxActive(config.getDbPoolMaxActive());
        ds.setMaxIdle(config.getDbPoolMaxIdle());
        ds.setMinIdle(config.getDbPoolMinIdle());
        ds.setMaxWait(config.getDbPoolMaxWait());

        Logging.getLogger()
                .info("Pool initialized (" + "initial size=" + config.getDbPoolInitialSize() + ", max active="
                        + config.getDbPoolMaxActive() + ", max idle=" + config.getDbPoolMaxIdle() + ", min idle="
                        + config.getDbPoolMinIdle() + ", max wait=" + config.getDbPoolMaxWait() + ")");

        //-- dynamic layer loading
        Class klass = Class.forName(config.getDbLayer());
        Class[] types = { DataSource.class };
        Object[] values = { ds };
        Constructor constr = klass.getConstructor(types);
        return (DatabaseAbstractionLayer) constr.newInstance(values);
    }

    /**
     * Get an opened connection
     *
     * @return the connection
     */
    public abstract Connection getConnection() throws SQLException;

    /**
     * Check if a table is existing in the system
     * 
     * @param tableName the name of the table
     * @return true if the database has this table
     */
    public boolean hasTable(String tableName) throws SQLException {
        boolean has = false;
        String[] types = { "TABLE" };
        Connection c = this.getConnection();
        ResultSet rs = c.getMetaData().getTables(null, null, null, types);

        while (!has && rs.next())
            has = rs.getString(3).equalsIgnoreCase(tableName);

        rs.close();
        c.close();

        return has;
    }

    /**
     * Escape a query (replace bad chars with escape codes)
     * 
     * @param query the query to escape
     * @return the escaped query
     */
    public String escape(String query) {
        return query.replaceAll("'", "\\'");
    }

    /**
     * Return an instance of xml table creator
     * @return the TableCreator
     */
    public TableCreator getTableCreator() {
        return new DefaultTableCreator();
    }

    /**
     * Resolve a logic type
     * 
     * @param type the logic type (see DBMSDataTypes on the wiki)
     * @return the implementation dependent type
     */
    public abstract String resolveType(String type);
}