/*
* SchemaCrawler
* Copyright (c) 2000-2009, Sualeh Fatehi.
*
* 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 schemacrawler.execute;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.logging.Level;
import java.util.logging.Logger;
import schemacrawler.schemacrawler.Query;
/**
* Executes SQL.
*
* @author Sualeh Fatehi
*/
public final class QueryExecutor
{
private static final Logger LOGGER = Logger.getLogger(QueryExecutor.class
.getName());
private final Connection connection;
private final DataHandler handler;
/**
* Constructs a SchemaCrawler object, from a connection.
*
* @param dataSource
* A data source.
* @param handler
* Execution handler.
* @throws QueryExecutorException
* On query execution error
*/
public QueryExecutor(final Connection connection, final DataHandler handler)
throws QueryExecutorException
{
if (connection == null)
{
throw new QueryExecutorException("No connection provided");
}
this.connection = connection;
if (handler == null)
{
throw new QueryExecutorException("No handler provided");
}
this.handler = handler;
}
/**
* Executes a SQL statement, and calls the registered handler on
* events.
*
* @param queryString
* SQL statement.
* @throws QueryExecutorException
* On query execution error
*/
public void executeSQL(final String queryString)
throws QueryExecutorException
{
final Query query = new Query("Ad hoc query", queryString);
LOGGER.fine("Executing: " + query);
Statement statement = null;
ResultSet resultSet = null;
try
{
statement = connection.createStatement();
resultSet = statement.executeQuery(query.getQuery());
handler.begin();
handler.handleData(query.getQuery(), resultSet);
handler.end();
}
catch (final SQLException e)
{
throw new QueryExecutorException(e.getMessage() + " - when executing - "
+ query, e);
}
finally
{
try
{
if (statement != null)
{
statement.close();
}
if (resultSet != null)
{
resultSet.close();
}
}
catch (final SQLException e)
{
LOGGER.log(Level.WARNING,
"Connection resources could not be released",
e);
}
}
}
}