org.hibernate.engine.jdbc.ColumnNameCache Maven / Gradle / Ivy
/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2008, Red Hat Middleware LLC or third-party contributors as
* indicated by the @author tags or express copyright attribution
* statements applied by the authors. All third-party contributions are
* distributed under license by Red Hat Middleware LLC.
*
* This copyrighted material is made available to anyone wishing to use, modify,
* copy, or redistribute it subject to the terms and conditions of the GNU
* Lesser General Public License, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this distribution; if not, write to:
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor
* Boston, MA 02110-1301 USA
*/
package org.hibernate.engine.jdbc;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
/**
* Cache of column-name -> column-index resolutions
*
* @author Steve Ebersole
*/
public class ColumnNameCache {
public static final float LOAD_FACTOR = .75f;
private final Map columnNameToIndexCache;
public ColumnNameCache(int columnCount) {
// should *not* need to grow beyond the size of the total number of columns in the rs
this.columnNameToIndexCache = new ConcurrentHashMap( columnCount + (int)( columnCount * LOAD_FACTOR ) + 1, LOAD_FACTOR );
}
public int getIndexForColumnName(String columnName, ResultSet rs) throws SQLException {
Integer cached = ( Integer ) columnNameToIndexCache.get( columnName );
if ( cached != null ) {
return cached.intValue();
}
else {
int index = rs.findColumn( columnName );
columnNameToIndexCache.put( columnName, index);
return index;
}
}
}