/*
* Copyright 2004-2007 Brian McCallister
*
* 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.skife.jdbi.v2;
import org.skife.jdbi.v2.tweak.StatementBuilder;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.HashMap;
import java.util.Map;
/**
* A StatementBuilder which decorates another StatementBuilder and caches
*/
public class CachingStatementBuilder implements StatementBuilder
{
private Map<String, PreparedStatement> cache = new HashMap<String, PreparedStatement>();
private final StatementBuilder builder;
/**
* Create a new CachingStatementBuilder which decorates the one passed in.
*
* @param builder The StatementBuilder used to actual PreparedStatement creation
*/
public CachingStatementBuilder(StatementBuilder builder) {
this.builder = builder;
}
/**
* Return either a cached PreparedStatement or a new one which has just been added to the cache
* @return A new, or cached, PreparedStatement
*/
public PreparedStatement create(Connection conn, String sql, StatementContext ctx) throws SQLException
{
if (cache.containsKey(sql)) {
PreparedStatement cached = cache.get(sql);
cached.clearParameters();
return cached;
}
PreparedStatement stmt = builder.create(conn, sql, ctx);
cache.put(sql, stmt);
return stmt;
}
/**
* NOOP, statements will be closed when the handle is closed
*/
public void close(Connection conn, String sql, Statement stmt) throws SQLException
{
}
/**
* Iterate over all cached statements and ask the wrapped StatementBuilder to close
* each one.
*/
public void close(Connection conn)
{
for (Map.Entry<String,PreparedStatement> statement : cache.entrySet()) {
try {
builder.close(conn, statement.getKey(), statement.getValue());
}
catch (SQLException e) {
// nothing we can do!
}
}
}
}