    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017
    018package org.apache.commons.dbcp2;
    019
    020import java.sql.PreparedStatement;
    021import java.sql.ResultSet;
    022import java.sql.SQLException;
    023import java.util.List;
    024
    025import org.apache.commons.pool2.KeyedObjectPool;
    026
    027/**
    028 * A {@link DelegatingPreparedStatement} that cooperates with {@link PoolingConnection} to implement a pool of
    029 * {@link PreparedStatement}s.
    030 * <p>
    031 * My {@link #close} method returns me to my containing pool. (See {@link PoolingConnection}.)
    032 *
    033 * @param <K>
    034 *            the key type
    035 *
    036 * @see PoolingConnection
    037 * @since 2.0
    038 */
    039public class PoolablePreparedStatement<K> extends DelegatingPreparedStatement {
    040    /**
    041     * The {@link KeyedObjectPool} from which I was obtained.
    042     */
    043    private final KeyedObjectPool<K, PoolablePreparedStatement<K>> pool;
    044
    045    /**
    046     * My "key" as used by {@link KeyedObjectPool}.
    047     */
    048    private final K key;
    049
    050    private volatile boolean batchAdded = false;
    051
    052    /**
    053     * Constructor
    054     *
    055     * @param stmt
    056     *            my underlying {@link PreparedStatement}
    057     * @param key
    058     *            my key" as used by {@link KeyedObjectPool}
    059     * @param pool
    060     *            the {@link KeyedObjectPool} from which I was obtained.
    061     * @param conn
    062     *            the {@link java.sql.Connection Connection} from which I was created
    063     */
    064    public PoolablePreparedStatement(final PreparedStatement stmt, final K key,
    065            final KeyedObjectPool<K, PoolablePreparedStatement<K>> pool, final DelegatingConnection<?> conn) {
    066        super(conn, stmt);
    067        this.pool = pool;
    068        this.key = key;
    069
    070        // Remove from trace now because this statement will be
    071        // added by the activate method.
    072        if (getConnectionInternal() != null) {
    073            getConnectionInternal().removeTrace(this);
    074        }
    075    }
    076
    077    /**
    078     * Add batch.
    079     */
    080    @Override
    081    public void addBatch() throws SQLException {
    082        super.addBatch();
    083        batchAdded = true;
    084    }
    085
    086    /**
    087     * Clear Batch.
    088     */
    089    @Override
    090    public void clearBatch() throws SQLException {
    091        batchAdded = false;
    092        super.clearBatch();
    093    }
    094
    095    /**
    096     * Return me to my pool.
    097     */
    098    @Override
    099    public void close() throws SQLException {
    100        // calling close twice should have no effect
    101        if (!isClosed()) {
    102            try {
    103                pool.returnObject(key, this);
    104            } catch (final SQLException e) {
    105                throw e;
    106            } catch (final RuntimeException e) {
    107                throw e;
    108            } catch (final Exception e) {
    109                throw new SQLException("Cannot close preparedstatement (return to pool failed)", e);
    110            }
    111        }
    112    }
    113
    114    @Override
    115    public void activate() throws SQLException {
    116        setClosedInternal(false);
    117        if (getConnectionInternal() != null) {
    118            getConnectionInternal().addTrace(this);
    119        }
    120        super.activate();
    121    }
    122
    123    @Override
    124    public void passivate() throws SQLException {
    125        // DBCP-372. clearBatch with throw an exception if called when the
    126        // connection is marked as closed.
    127        if (batchAdded) {
    128            clearBatch();
    129        }
    130        setClosedInternal(true);
    131        if (getConnectionInternal() != null) {
    132            getConnectionInternal().removeTrace(this);
    133        }
    134
    135        // The JDBC spec requires that a statement closes any open
    136        // ResultSet's when it is closed.
    137        // FIXME The PreparedStatement we're wrapping should handle this for us.
    138        // See bug 17301 for what could happen when ResultSets are closed twice.
    139        final List<AbandonedTrace> resultSets = getTrace();
    140        if (resultSets != null) {
    141            final ResultSet[] set = resultSets.toArray(new ResultSet[resultSets.size()]);
    142            for (final ResultSet element : set) {
    143                element.close();
    144            }
    145            clearTrace();
    146        }
    147
    148        super.passivate();
    149    }
    150}