org.callimachusproject.sql.PoolableDriverConnectionFactory.java Source code

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Here is the source code for org.callimachusproject.sql.PoolableDriverConnectionFactory.java

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/*
 * Copyright (c) 2013 3 Round Stones Inc., Some Rights Reserved
 *
 * 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.
 *
 */
package org.callimachusproject.sql;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import org.apache.commons.dbcp.ConnectionFactory;
import org.apache.commons.pool.ObjectPool;
import org.apache.commons.pool.PoolableObjectFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class PoolableDriverConnectionFactory implements PoolableObjectFactory<PoolableDriverConnection> {

    private final Logger logger = LoggerFactory.getLogger(PoolableDriverConnectionFactory.class);
    private final ConnectionFactory factory;
    private final String validationQuery;
    private volatile ObjectPool<PoolableDriverConnection> pool = null;

    /**
     * @param connFactory
     *            the {@link ConnectionFactory} from which to obtain base
     *            {@link Connection}s
     * @param validationQuery
     *            SQL SELECT query to validate connections
     */
    public PoolableDriverConnectionFactory(ConnectionFactory connFactory, String validationQuery) {
        this.factory = connFactory;
        this.validationQuery = validationQuery;
    }

    /**
     * @param pool
     *            the {@link ObjectPool} in which to pool those
     *            {@link Connection}s
     */
    public synchronized void setPool(ObjectPool<PoolableDriverConnection> pool) {
        if (null != this.pool && this.pool != pool) {
            try {
                this.pool.close();
            } catch (Exception e) {
                logger.warn(e.toString(), e);
            }
        }
        this.pool = pool;
    }

    public PoolableDriverConnection makeObject() throws Exception {
        Connection conn = factory.createConnection();
        if (conn == null) {
            throw new IllegalStateException("Connection factory returned null from createConnection");
        }
        if (conn.isClosed()) {
            throw new SQLException("connection closed");
        }
        return new PoolableDriverConnection(conn, pool);
    }

    public void destroyObject(PoolableDriverConnection obj) throws Exception {
        if (obj instanceof PoolableDriverConnection) {
            ((PoolableDriverConnection) obj).reallyClosing();
        }
    }

    public boolean validateObject(PoolableDriverConnection conn) {
        try {
            if (conn.isClosed()) {
                throw new SQLException("connection closed");
            }
            if (null == validationQuery)
                return true;
            Statement stmt = conn.createStatement();
            try {
                ResultSet rset = stmt.executeQuery(validationQuery);
                try {
                    return rset.next();
                } finally {
                    rset.close();
                }
            } finally {
                stmt.close();
            }
        } catch (SQLException e) {
            return false;
        }
    }

    public void passivateObject(PoolableDriverConnection conn) throws Exception {
        if (!conn.getAutoCommit() && !conn.isReadOnly()) {
            conn.rollback();
        }
        conn.clearWarnings();
        if (!conn.getAutoCommit()) {
            conn.setAutoCommit(true);
        }
        conn.passivate();
    }

    public void activateObject(PoolableDriverConnection conn) throws Exception {
        conn.activate();
        if (conn.getAutoCommit() != true) {
            conn.setAutoCommit(true);
        }
    }
}