/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2006-2008, Open Source Geospatial Foundation (OSGeo)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library 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.
*
*/
package org.geotools.filter;
import java.io.Writer;
import java.util.Map;
import org.geotools.data.jdbc.FilterToSQL;
import org.opengis.filter.expression.PropertyName;
public class UnaliasSQLEncoder extends FilterToSQL {
private Map aliases;
public UnaliasSQLEncoder(Map aliases) {
super();
this.aliases = aliases;
}
public UnaliasSQLEncoder() {
aliases = null;
}
public UnaliasSQLEncoder(Map aliases, Writer out) throws SQLEncoderException {
super(out);
this.aliases = aliases;
}
public void setAliases(Map aliases) {
this.aliases = aliases;
}
/**
* Writes the SQL for the attribute Expression.
*
* @param expression
* the attribute to turn to SQL.
*
* @throws RuntimeException
* for io exception with writer
*/
public Object visit(PropertyName expression, Object extraData) throws RuntimeException {
if (this.aliases == null) {
super.visit(expression, extraData);
return null;
}
String alias = expression.getPropertyName();
String sqlExpression = (String) this.aliases.get(alias);
if (sqlExpression == null) {
throw new IllegalStateException("Unkown sql expression for attribute " + alias);
}
try {
out.write(escapeName(sqlExpression));
} catch (java.io.IOException ioe) {
throw new RuntimeException("IO problems writing attribute exp", ioe);
}
return extraData;
}
}