Sqlite.java

package eu.play_project.dcep.distributedetalis.persistence;

import java.io.File;
import java.io.Serializable;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.HashSet;
import java.util.Set;

public class Sqlite implements Persistence {

	private Connection sqliteConn;
	final String sqliteTable = "subscriptionsEc";

	
	
	public Sqlite() throws PersistenceException {
		this(
				new File(System.getProperty("java.io.tmpdir") + File.pathSeparator + "play-dcep"
						+ File.pathSeparator + "dcep.db"));
		// TODO stuehmer: this should be unique for more than one Detalis instance per machine
	}
	
	public Sqlite(File dbFile) throws PersistenceException {

		try {
			Class.forName(org.sqlite.JDBC.class.getName());
			sqliteConn = DriverManager.getConnection("jdbc:sqlite:" + dbFile.getPath());
			sqliteConn.setAutoCommit(true);
	        Statement stat = sqliteConn.createStatement();
	        stat.executeUpdate(String.format("CREATE TABLE IF NOT EXISTS %s (cloudId, subscriptionId);", sqliteTable)); // if not exists
	        
			
		} catch (ClassNotFoundException e) {
			throw new PersistenceException("Error retrieving old subscriptions from database.", e);
		} catch (SQLException e) {
			throw new PersistenceException("Error retrieving old subscriptions from database.", e);
		}
	}
	
	/* (non-Javadoc)
	 * @see eu.play_project.dcep.distributedetalis.persistence.Persistence#storeSubscription(java.lang.String, java.lang.String)
	 */
	@Override
	public void storeSubscription(String cloudId, String subscriptionId) {
		try {
			sqliteConn.createStatement().execute(
							String.format("INSERT INTO %s VALUES ('%s', '%s');", sqliteTable,
									cloudId, subscriptionId));
		} catch (SQLException e) {
			e.printStackTrace();
		}
	}

	/* (non-Javadoc)
	 * @see eu.play_project.dcep.distributedetalis.persistence.Persistence#deleteAllSubscriptions()
	 */
	@Override
	public void deleteAllSubscriptions() {
		try {
			sqliteConn.createStatement().execute(String.format("DELETE FROM %s;", sqliteTable));
		} catch (SQLException e) {
			e.printStackTrace();
		}
	}

	/* (non-Javadoc)
	 * @see eu.play_project.dcep.distributedetalis.persistence.Persistence#getSubscriptions()
	 */
	@Override
	public Set<SubscriptionPerCloud> getSubscriptions() throws PersistenceException {

		Set<SubscriptionPerCloud> persistedSubscriptions = new HashSet<SubscriptionPerCloud>();
		
		try {
			ResultSet rs = sqliteConn.createStatement().executeQuery(
					String.format("SELECT cloudId, subscriptionId FROM %s;", sqliteTable));
			while (rs.next()) {
				final String cloudId = rs.getString("cloudId");
				final String subscriptionId = rs.getString("subscriptionId");
				
				persistedSubscriptions.add(new SubscriptionPerCloud(cloudId, subscriptionId));
			}
			rs.close();

		} catch (SQLException e) {
			throw new PersistenceException(
					"Error retrieving old subscriptions from database.", e);
		}
		
		return persistedSubscriptions;
	}
	
	public class SubscriptionPerCloud implements Serializable {

		private static final long serialVersionUID = 100L;

		public SubscriptionPerCloud(String cloudId, String subscriptionId) {
			this.subscriptionId = subscriptionId;
			this.cloudId = cloudId;
		}

		public String subscriptionId;
		public String cloudId;
	}

}