Commons DBCP example source code file (PooledConnectionProxy.java)

This example Commons DBCP source code file (PooledConnectionProxy.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Commons DBCP tags/keywords

collection, connection, connectionevent, connectionevent, connectioneventlistener, connectioneventlistener, jdbc, object, object, pooledconnection, pooledconnectionproxy, pooledconnectionproxy, sql, sqlexception, util, vector

The Commons DBCP PooledConnectionProxy.java source code

/*
 * 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.datasources;

import java.sql.Connection;
import java.sql.SQLException;

import java.util.Collection;
import java.util.Vector;

import javax.sql.ConnectionEvent;
import javax.sql.ConnectionEventListener;
import javax.sql.PooledConnection;
/* JDBC_4_ANT_KEY_BEGIN */
import javax.sql.StatementEventListener;
/* JDBC_4_ANT_KEY_END */

/**
 * PooledConnection implementation that wraps a driver-supplied
 * PooledConnection and proxies events, allowing behavior to be
 * modified to simulate behavior of different implementations.
 * 
 * @version $Revision$ $Date$
 */
public class PooledConnectionProxy implements PooledConnection,
    ConnectionEventListener {

    protected PooledConnection delegate = null;
    
    /**
     * ConnectionEventListeners
     */
    private Vector eventListeners = new Vector();
    
    /** 
     * True means we will (dubiously) notify listeners with a
     * ConnectionClosed event when this (i.e. the PooledConnection itself)
     * is closed
     */
    private boolean notifyOnClose = false;
    
    public PooledConnectionProxy(PooledConnection pooledConnection) {
        this.delegate = pooledConnection;
        pooledConnection.addConnectionEventListener(this);
    }

    /** 
     * If notifyOnClose is on, notify listeners
     */
    public void close() throws SQLException {
        delegate.close();
        if (isNotifyOnClose()) {
           notifyListeners();
        }
    }

    public Connection getConnection() throws SQLException {
        return delegate.getConnection();
    }

    /**
     * Remove event listeners.
     */
    public void removeConnectionEventListener(ConnectionEventListener listener) {
        eventListeners.remove(listener);
    }

    /* JDBC_4_ANT_KEY_BEGIN */
    public void removeStatementEventListener(StatementEventListener listener) {
        eventListeners.remove(listener);
    }
    /* JDBC_4_ANT_KEY_END */

    public boolean isNotifyOnClose() {
        return notifyOnClose;
    }

    public void setNotifyOnClose(boolean notifyOnClose) {
        this.notifyOnClose = notifyOnClose;
    }
    
    /**
     * sends a connectionClosed event to listeners.
     */
    void notifyListeners() {
        ConnectionEvent event = new ConnectionEvent(this);
        Object[] listeners = eventListeners.toArray();
        for (int i = 0; i < listeners.length; i++) {
            ((ConnectionEventListener) listeners[i]).connectionClosed(event);
        }
    }
    
    /**
     * Add event listeners.
     */
    public void addConnectionEventListener(ConnectionEventListener listener) {
        if (!eventListeners.contains(listener)) {
            eventListeners.add(listener);
        }
    }

    /* JDBC_4_ANT_KEY_BEGIN */
    public void addStatementEventListener(StatementEventListener listener) {
        if (!eventListeners.contains(listener)) {
            eventListeners.add(listener);
        }
    }
    /* JDBC_4_ANT_KEY_END */
    
    /**
     * Pass closed events on to listeners
     */
    public void connectionClosed(ConnectionEvent event) {
        notifyListeners();    
    }

    /**
     * Pass error events on to listeners
     */ 
    public void connectionErrorOccurred(ConnectionEvent event) {
        Object[] listeners = eventListeners.toArray();
        for (int i = 0; i < listeners.length; i++) {
            ((ConnectionEventListener) listeners[i]).connectionErrorOccurred(event);
        } 
    }
    
    /**
     * Generate a connection error event
     */
    public void throwConnectionError() {
        ConnectionEvent event = new ConnectionEvent(this);
        connectionErrorOccurred(event);
    }
    
    /**
     * Expose listeners
     */
    public Collection getListeners() {
        return eventListeners;
    }

}