/*

 * Licensed to the Apache Software Foundation (ASF) under one or more

 * contributor license agreements.  See the NOTICE file distributed with

 * this work for additional information regarding copyright ownership.

 * The ASF licenses this file to You 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.

 */

package org.apache.commons.dbcp;

import java.sql.Connection;

import java.sql.SQLException;

import org.apache.commons.pool.ObjectPool;

/**

 * A delegating connection that, rather than closing the underlying

 * connection, returns itself to an {@link ObjectPool} when

 * closed.

 *

 * @author Rodney Waldhoff

 * @author Glenn L. Nielsen

 * @author James House

 */

public class PoolableConnection extends DelegatingConnection {

    /** The pool to which I should return. */

    // TODO: Correct use of the pool requires that this connection is only every returned to the pool once.

    protected ObjectPool _pool = null;

    /**

     *

     * @param conn my underlying connection

     * @param pool the pool to which I should return when closed

     */

    public PoolableConnection(Connection conn, ObjectPool pool) {

        super(conn);

        _pool = pool;

    }

    /**

     *

     * @param conn my underlying connection

     * @param pool the pool to which I should return when closed

     * @param config the abandoned configuration settings

     */

    public PoolableConnection(Connection conn, ObjectPool pool, AbandonedConfig config) {

        super(conn, config);

        _pool = pool;

    }

    /**

     * Returns me to my pool.

     */

     public synchronized void close() throws SQLException {

        if (_closed) {

            // already closed

            return;

        }

        boolean isUnderlyingConectionClosed;

        try {

            isUnderlyingConectionClosed = _conn.isClosed();

        } catch (SQLException e) {

            try {

                _pool.invalidateObject(this); // XXX should be guarded to happen at most once

            } catch(IllegalStateException ise) {

                // pool is closed, so close the connection

                passivate();

                getInnermostDelegate().close();

            } catch (Exception ie) {

                // DO NOTHING the original exception will be rethrown

            }

            throw (SQLException) new SQLException("Cannot close connection (isClosed check failed)").initCause(e);

        }

        if (!isUnderlyingConectionClosed) {

            // Normal close: underlying connection is still open, so we

            // simply need to return this proxy to the pool

            try {

                _pool.returnObject(this); // XXX should be guarded to happen at most once

            } catch(IllegalStateException e) {

                // pool is closed, so close the connection

                passivate();

                getInnermostDelegate().close();

            } catch(SQLException e) {

                throw e;

            } catch(RuntimeException e) {

                throw e;

            } catch(Exception e) {

                throw (SQLException) new SQLException("Cannot close connection (return to pool failed)").initCause(e);

            }

        } else {

            // Abnormal close: underlying connection closed unexpectedly, so we

            // must destroy this proxy

            try {

                _pool.invalidateObject(this); // XXX should be guarded to happen at most once

            } catch(IllegalStateException e) {

                // pool is closed, so close the connection

                passivate();

                getInnermostDelegate().close();

            } catch (Exception ie) {

                // DO NOTHING, "Already closed" exception thrown below

            }

            throw new SQLException("Already closed.");

        }

    }

    /**

     * Actually close my underlying {@link Connection}.

     */

    public void reallyClose() throws SQLException {

        super.close();

    }

}