    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 *      https://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 */
    017package org.apache.commons.dbcp2;
    018
    019import java.sql.PreparedStatement;
    020import java.sql.SQLException;
    021
    022import org.apache.commons.pool2.KeyedObjectPool;
    023
    024/**
    025 * A {@link DelegatingPreparedStatement} that cooperates with {@link PoolingConnection} to implement a pool of
    026 * {@link PreparedStatement}s.
    027 * <p>
    028 * My {@link #close} method returns me to my containing pool. (See {@link PoolingConnection}.)
    029 * </p>
    030 *
    031 * @param <K>
    032 *            the key type
    033 *
    034 * @see PoolingConnection
    035 * @since 2.0
    036 */
    037public class PoolablePreparedStatement<K> extends DelegatingPreparedStatement {
    038
    039    /**
    040     * The {@link KeyedObjectPool} from which I was obtained.
    041     */
    042    private final KeyedObjectPool<K, PoolablePreparedStatement<K>> pool;
    043
    044    /**
    045     * My "key" as used by {@link KeyedObjectPool}.
    046     */
    047    private final K key;
    048
    049    private volatile boolean batchAdded;
    050
    051    /**
    052     * Constructs a new instance.
    053     *
    054     * @param stmt
    055     *            my underlying {@link PreparedStatement}
    056     * @param key
    057     *            my key as used by {@link KeyedObjectPool}
    058     * @param pool
    059     *            the {@link KeyedObjectPool} from which I was obtained.
    060     * @param conn
    061     *            the {@link java.sql.Connection Connection} from which I was created
    062     */
    063    public PoolablePreparedStatement(final PreparedStatement stmt, final K key,
    064            final KeyedObjectPool<K, PoolablePreparedStatement<K>> pool, final DelegatingConnection<?> conn) {
    065        super(conn, stmt);
    066        this.pool = pool;
    067        this.key = key;
    068
    069        // Remove from trace now because this statement will be
    070        // added by the activate method.
    071        removeThisTrace(conn);
    072    }
    073
    074    @Override
    075    public void activate() throws SQLException {
    076        setClosedInternal(false);
    077        add(getConnectionInternal(), this);
    078        super.activate();
    079    }
    080
    081    /**
    082     * Add batch.
    083     */
    084    @Override
    085    public void addBatch() throws SQLException {
    086        super.addBatch();
    087        batchAdded = true;
    088    }
    089
    090    /**
    091     * Clear Batch.
    092     */
    093    @Override
    094    public void clearBatch() throws SQLException {
    095        batchAdded = false;
    096        super.clearBatch();
    097    }
    098
    099    /**
    100     * Return me to my pool.
    101     */
    102    @Override
    103    public void close() throws SQLException {
    104        // calling close twice should have no effect
    105        if (!isClosed()) {
    106            try {
    107                pool.returnObject(key, this);
    108            } catch (final SQLException | RuntimeException e) {
    109                throw e;
    110            } catch (final Exception e) {
    111                throw new SQLException("Cannot close preparedstatement (return to pool failed)", e);
    112            }
    113        }
    114    }
    115
    116    /**
    117     * Package-protected for tests.
    118     *
    119     * @return The key.
    120     */
    121    K getKey() {
    122        return key;
    123    }
    124
    125    @Override
    126    public void passivate() throws SQLException {
    127        // DBCP-372. clearBatch with throw an exception if called when the
    128        // connection is marked as closed.
    129        if (batchAdded) {
    130            clearBatch();
    131        }
    132        prepareToReturn();
    133    }
    134}