/**
* 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.mahout.cf.taste.impl.model.jdbc;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.SQLFeatureNotSupportedException;
import java.util.logging.Logger;
import javax.sql.DataSource;
import org.apache.commons.dbcp.ConnectionFactory;
import org.apache.commons.dbcp.PoolableConnectionFactory;
import org.apache.commons.dbcp.PoolingDataSource;
import org.apache.commons.pool.impl.GenericObjectPool;
import com.google.common.base.Preconditions;
/**
* <p>
* A wrapper {@link DataSource} which pools connections.
* </p>
*/
public final class ConnectionPoolDataSource implements DataSource {
private final DataSource delegate;
public ConnectionPoolDataSource(DataSource underlyingDataSource) {
Preconditions.checkNotNull(underlyingDataSource);
ConnectionFactory connectionFactory = new ConfiguringConnectionFactory(underlyingDataSource);
GenericObjectPool objectPool = new GenericObjectPool();
objectPool.setTestOnBorrow(false);
objectPool.setTestOnReturn(false);
objectPool.setTestWhileIdle(true);
objectPool.setTimeBetweenEvictionRunsMillis(60 * 1000L);
// Constructor actually sets itself as factory on pool
new PoolableConnectionFactory(connectionFactory, objectPool, null, "SELECT 1", false, false);
delegate = new PoolingDataSource(objectPool);
}
@Override
public Connection getConnection() throws SQLException {
return delegate.getConnection();
}
@Override
public Connection getConnection(String username, String password) throws SQLException {
return delegate.getConnection(username, password);
}
@Override
public PrintWriter getLogWriter() throws SQLException {
return delegate.getLogWriter();
}
@Override
public void setLogWriter(PrintWriter printWriter) throws SQLException {
delegate.setLogWriter(printWriter);
}
@Override
public void setLoginTimeout(int timeout) throws SQLException {
delegate.setLoginTimeout(timeout);
}
@Override
public int getLoginTimeout() throws SQLException {
return delegate.getLoginTimeout();
}
@Override
public <T> T unwrap(Class<T> iface) throws SQLException {
return delegate.unwrap(iface);
}
@Override
public boolean isWrapperFor(Class<?> iface) throws SQLException {
return delegate.isWrapperFor(iface);
}
// This exists for compatibility with Java 7 / JDBC 4.1, but doesn't exist
// in Java 6. In Java 7 it would @Override, but not in 6.
// @Override
public Logger getParentLogger() throws SQLFeatureNotSupportedException {
throw new SQLFeatureNotSupportedException();
}
private static class ConfiguringConnectionFactory implements ConnectionFactory {
private final DataSource underlyingDataSource;
ConfiguringConnectionFactory(DataSource underlyingDataSource) {
this.underlyingDataSource = underlyingDataSource;
}
@Override
public Connection createConnection() throws SQLException {
Connection connection = underlyingDataSource.getConnection();
connection.setTransactionIsolation(Connection.TRANSACTION_READ_UNCOMMITTED);
connection.setHoldability(ResultSet.CLOSE_CURSORS_AT_COMMIT);
return connection;
}
}
}