embedconnectioncontext.java

derby database source code.good for you.

/*

   Derby - Class org.apache.derby.impl.jdbc.EmbedConnectionContext

   Copyright 1997, 2004 The Apache Software Foundation or its licensors, as applicable.

   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.

 */

//depot/main/java/org.apache.derby.impl.jdbc/EmbedConnectionContext.java#24 - edit change 16899 (text)
package org.apache.derby.impl.jdbc;

// This is the recommended super-class for all contexts.
import org.apache.derby.iapi.services.context.ContextImpl;
import org.apache.derby.iapi.services.context.ContextManager;
import org.apache.derby.iapi.sql.conn.StatementContext;
import org.apache.derby.iapi.jdbc.ConnectionContext;
import org.apache.derby.iapi.error.StandardException;
import org.apache.derby.iapi.sql.ResultSet;

import org.apache.derby.iapi.error.ExceptionSeverity;
import java.sql.SQLException;
import java.util.Vector;
import java.util.Enumeration;
/**
	@author djd
 */
public class EmbedConnectionContext extends ContextImpl 
		implements ConnectionContext
{

	/**
		We hold a soft reference to the connection so that when the application
		releases its reference to the Connection without closing it, its finalize
		method will be called, which will then close the connection. If a direct
		reference is used here, such a Connection will never be closed or garbage
		collected as modules hold onto the ContextManager and thus there would
		be a direct reference through this object.
	*/
	private java.lang.ref.SoftReference	connRef;


	EmbedConnectionContext(ContextManager cm, EmbedConnection conn) {
		super(cm, ConnectionContext.CONTEXT_ID);

		connRef = new java.lang.ref.SoftReference(conn);
	}

	public void cleanupOnError(Throwable error) {

		if (connRef == null)
			return;

		EmbedConnection conn = (EmbedConnection) connRef.get();

		if (error instanceof StandardException) {

			StandardException se = (StandardException) error;
			if (se.getSeverity() < ExceptionSeverity.SESSION_SEVERITY) {

				// any error in auto commit mode that does not close the
				// session will cause a rollback, thus remvoing the need
				// for any commit. We could check this flag under autoCommit
				// being true but the flag is ignored when autoCommit is false
				// so why add the extra check
				if (conn != null) {
					conn.needCommit = false;
				}
				return;
			}
		}

		// This may be a transaction without connection.
		if (conn != null)
			conn.setInactive(); // make the connection inactive & empty

		connRef = null;
		popMe();
	}

	//public java.sql.Connection getEmbedConnection()
	//{
	///	return conn;
	//}

	/**
		Get a connection equivalent to the call
		<PRE>
		DriverManager.getConnection("jdbc:default:connection");
		</PRE>
	*/
	public java.sql.Connection getNestedConnection(boolean internal) throws SQLException {

		EmbedConnection conn = (EmbedConnection) connRef.get();

		if ((conn == null) || conn.isClosed())
			throw Util.noCurrentConnection();

		if (!internal) {
			StatementContext sc = conn.getLanguageConnection().getStatementContext();
			if ((sc == null) || (sc.getSQLAllowed() < org.apache.derby.catalog.types.RoutineAliasInfo.MODIFIES_SQL_DATA))
				throw Util.noCurrentConnection();
		}

		return conn.getLocalDriver().getNewNestedConnection(conn);
	}

	/**
	 * Get a jdbc ResultSet based on the execution ResultSet.
	 *
	 * @param executionResultSet	a result set as gotten from execution
	 *	
	 */	
	public java.sql.ResultSet getResultSet
	(
		ResultSet 				executionResultSet
	) throws SQLException
	{
		EmbedConnection conn = (EmbedConnection) connRef.get();

		EmbedResultSet rs = conn.getLocalDriver().newEmbedResultSet(conn, executionResultSet, 
							false, (EmbedStatement) null, true);
		return rs;
	}
}