database-resource-manager/src/main/java/org/gcube/dataanalysis/databases/utils/DatabaseFactory.java

package org.gcube.dataanalysis.databases.utils;

import java.io.ByteArrayInputStream;
import java.util.List;

import javax.xml.parsers.DocumentBuilderFactory;

import org.gcube.contentmanagement.lexicalmatcher.utils.AnalysisLogger;
import org.gcube.contentmanagement.lexicalmatcher.utils.FileTools;
import org.hibernate.MappingException;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;

/** Class that allows to connect to a database and to execute a query */
public class DatabaseFactory {

	// Method that establish a connection with the database
	public static SessionFactory initDBConnection(String configurationFile)
			throws Exception {
		String xml = FileTools.readXMLDoc(configurationFile);
		SessionFactory DBSessionFactory = null;
		Configuration cfg = new Configuration();
		cfg = cfg.configure(DocumentBuilderFactory.newInstance()
				.newDocumentBuilder()
				.parse(new ByteArrayInputStream(xml.getBytes())));
		DBSessionFactory = cfg.buildSessionFactory();
		return DBSessionFactory;
	}

	// Method that execute the query
	public static List<Object> executeSQLQuery(String query,
			SessionFactory DBSessionFactory) throws Exception {
		// System.out.println("QUERY: "+query);
		try {
			return executeHQLQuery(query, DBSessionFactory, true);

		} catch (Exception e) {
			// TODO: handle exception
			throw e;
		}

	}

	public static List<Object> executeHQLQuery(String query,
			SessionFactory DBSessionFactory, boolean useSQL) throws Exception,
			MappingException {
		Session ss = null;
		List<Object> obj = null;

		try {

			ss = DBSessionFactory.getCurrentSession();

			ss.beginTransaction();

			Query qr = null;

			if (useSQL)
				qr = ss.createSQLQuery(query);
			else
				qr = ss.createQuery(query);

			List<Object> result = null;

			AnalysisLogger.getLogger().debug(
					"In DatabaseFactory->" + qr.getQueryString());
			try {
				result = qr.list();
				ss.getTransaction().commit();

				if (result == null)
					System.out
							.println("Hibernate doesn't return a valid object when org.gcube.contentmanagement.lexicalmatcher retrieve UserState Object");

				// if (result != null && result.size() == 0)
				// System.out.println(String.format("found nothing in database for query: "+query));

				if (result != null && result.size() != 0) {
					obj = result;
				}

				rollback(ss);

				return obj;

			} catch (Exception e) {
				

				if (e.getClass()
						.toString()
						.contains("org.hibernate.exception.SQLGrammarException")) {

					// System.out.println(e.getCause().getMessage());

					// AnalysisLogger.getLogger().debug("In ConnectionManager-> ERROR The query could not be executed: SQL grammar error in the query");

					// throw new
					// Exception("The query could not be executed: SQL grammar error in the query");

					AnalysisLogger.getLogger().debug(
							"In DatabaseFactory-> "
									+ e.getCause().getLocalizedMessage());
					throw new Exception(e.getCause().getMessage());

				}

				// if (e.getClass()
				// .toString()
				// .contains(
				// "com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException"))
				// {
				//
				// // System.out.println(e.getClass().toString());
				//
				// AnalysisLogger.getLogger().debug(
				// "In DatabaseFactory-> "
				// + e.getCause().getLocalizedMessage());
				//
				// throw new Exception(e.getCause().getMessage());
				// }

				else {
					throw e;

				}

			}

		} catch (Exception e) {

			throw e;
		}

	}

	public static void rollback(Session ss) {

		try {
			if (ss != null && ss.getTransaction() != null)
				ss.getTransaction().rollback();
		} catch (Exception ex) {
			// throw ex;

		} finally {
			try {
				ss.close();
			} catch (Exception ee) {

				// throw ee;
			}
		}
	}

	// public static void executeSQLUpdate(String query, SessionFactory
	// DBSessionFactory) throws Exception {
	// executeHQLUpdate(query, DBSessionFactory, true);
	// }

	// public static void executeHQLUpdate(String query, SessionFactory
	// DBSessionFactory, boolean useSQL) throws Exception{
	// // System.out.println("executing query: " + query);
	// Session ss = null;
	//
	// try {
	//
	// ss = DBSessionFactory.getCurrentSession();
	// // System.out.println("executing query");
	// ss.beginTransaction();
	// Query qr = null;
	//
	// if (useSQL)
	// qr = ss.createSQLQuery(query);
	// else
	// qr = ss.createQuery(query);
	//
	// qr.executeUpdate();
	// ss.getTransaction().commit();
	//
	// } catch (Exception e) {
	// AnalysisLogger.getLogger().debug(query);
	// rollback(ss);
	// // e.printStackTrace();
	// throw e;
	// }
	// }

}