MigrationManager.java

/**
 * TNTConcept Easy Enterprise Management by Autentia Real Bussiness Solution S.L.
 * Copyright (C) 2007 Autentia Real Bussiness Solution S.L.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package com.autentia.tnt.manager.data;

import com.autentia.tnt.manager.data.exception.DataException;
import com.autentia.tnt.util.HibernateUtil;
import com.autentia.tnt.version.Version;

import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.LineNumberReader;
import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Locale;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.hibernate.Session;

/**
 * 
 * @author ivan
 */
public class MigrationManager {

	/** Logger */
	private static final Log		log				= LogFactory.getLog(MigrationManager.class);

	/** Package where SQL scripts live */
	private static final String		SCRIPT_PREFIX	= "com/autentia/tnt/sql/mysql/";

	/** Script file name */
	private static final String		SCRIPT_SUFFIX	= "/upgrade.sql";

	/** Default DB migration handler */
	private static MigrationManager	defaultManager	= new MigrationManager();

	/**
	 * 
	 * @return
	 */
	public static MigrationManager getDefault() {
		return defaultManager;
	}

	/**
	 * @return the original database version
	 * @throws com.autentia.tnt.manager.data.exception.DataException
	 */
	public Version upgradeDatabase() throws DataException {
		Version ret = null;
		Version db = null;
		Version code = Version.getApplicationVersion();
		Session ses = HibernateUtil.getSessionFactory().openSession();
		Connection con = ses.connection();
		Statement stmt = null;
		LineNumberReader file = null;
		String delimiter = ";";

		try {
			db = Version.getDatabaseVersion();
			ret = db.clone();
			log.info("upgradeDatabase - >>>> STARTING MIGRATION FROM " + db + " TO " + code
					+ " <<<<");

			// Disable auto-commit (just in case...)
			log.info("upgradeDatabase - disabling auto commit");
			con.setAutoCommit(false);

			// Create statement
			stmt = con.createStatement();

			// While necessary, upgrade database
			while (db.compareTo(code, Version.MINOR) < 0) {
				log.info("upgradeDatabase - " + db);

				// Compose script name and open it
				String script = SCRIPT_PREFIX + db.toString(Version.MINOR) + SCRIPT_SUFFIX;
				log.info("upgradeDatabase - loading script " + script);
				InputStream sqlScript = Thread.currentThread().getContextClassLoader().getResourceAsStream(script);
				if (sqlScript == null) {
					throw FileNotFoundException(script);
				}
				file = new LineNumberReader(new InputStreamReader(
						new BufferedInputStream(sqlScript), "UTF-8"));
				int _c;

				// Add batched SQL sentences to statement
				StringBuilder sentence = new StringBuilder();
				String line;
				while ((line = file.readLine()) != null) {
					line = line.trim();
					if (!line.startsWith("--")) {
						// Interpret "DELIMITER" sentences
						if (line.trim().toUpperCase(Locale.ENGLISH).startsWith("DELIMITER")) {
							delimiter = line.trim().substring("DELIMITER".length()).trim();
						} else {
							// Add line to sentence
							if (line.endsWith(delimiter)) {
								// Remove delimiter
								String lastLine = line.substring(0, line.length()
										- delimiter.length());

								// Append line to sentence
								sentence.append(lastLine);

								// Execute sentence
								log.info(" " + sentence.toString());
								stmt.addBatch(sentence.toString());

								// Prepare new sentence
								sentence = new StringBuilder();
							} else {
								// Append line to sentence
								sentence.append(line);

								// Append separator for next line
								sentence.append(" ");
							}
						}
					}
				}

				// Execute batch
				log.info("upgradeDatabase - executing batch of commands");
				stmt.executeBatch();

				// Re-read database version
				Version old = db;
				db = Version.getDatabaseVersion(con);
				if (old.equals(db)) {
					throw new DataException("Script was applied but did not upgrade database: "
							+ script);
				}
				log.info("upgradeDatabase - database upgraded to version " + db);
			}

			// Commit transaction
			log.info("upgradeDatabase - commiting changes to database");
			con.commit();

			// Report end of migration
			log.info("upgradeDatabase - >>>> MIGRATION SUCCESSFULLY FINISHED <<<<");
		} catch (Exception e) {
			log.error("upgradeDatabase - >>>> MIGRATION FAILED: WILL BE ROLLED BACK <<<<", e);
			try {
				con.rollback();
			} catch (SQLException e2) {
				log.error("upgradeDatabase - Error al realizar el rollback");
			}
			throw new DataException("Script was applied but did not upgrade database: ", e);
		} finally {
			if (file != null) {
				try {
					file.close();
				} catch (IOException e2) {
					log.error("upgradeDatabase - Error al cerrar el fichero de script ", e2);
				}
			}
			if (stmt != null) {
				try {
					stmt.close();
				} catch (SQLException e2) {
					log.error("upgradeDatabase - Error al cerrar el statement");
				}
			}
			ses.close();
		}

		return ret;
	}

	private Exception FileNotFoundException(String script) {
		throw new UnsupportedOperationException("Not yet implemented");
	}
}