/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2002-2008, 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.arcsde.data.view;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import net.sf.jsqlparser.expression.Expression;
import net.sf.jsqlparser.schema.Table;
import net.sf.jsqlparser.statement.select.FromItem;
import net.sf.jsqlparser.statement.select.OrderByElement;
import net.sf.jsqlparser.statement.select.PlainSelect;
import net.sf.jsqlparser.statement.select.SelectItem;
import net.sf.jsqlparser.statement.select.Union;
import org.geotools.arcsde.session.ISession;
/**
* Visitor on a PlainSelect that produces another one but with all the table names and field names
* fully qualified as expected by ArcSDE.
* <p>
* At any time may throw an IllegalArgumentException if a table or field name stated in the
* PlainSelect is not found on the arcsde instance.
* </p>
* <p>
* Usage:
*
* <pre>
* <code>
* PlainSelect unqualifiedSelect = ...
* SeConnection conn = ...
* SelectVisitor visitor = new SelectVisitor(conn);
* visitor.accept(unqualifiedSelect);
*
* PlainSelect qualifiedSelect = visitor.getQualifiedQuery();
* </code>
* </pre>
*
* </p>
*
* @author Gabriel Roldan, Axios Engineering
* @version $Id$
*
* @source $URL$
* http://svn.geotools.org/geotools/trunk/gt/modules/plugin/arcsde/datastore/src/main/java
* /org/geotools/arcsde/data/view/SelectQualifier.java $
* @since 2.3.x
*/
public class SelectQualifier implements net.sf.jsqlparser.statement.select.SelectVisitor {
private ISession session;
private PlainSelect qualifiedSelect;
/**
* Creates a new SelectQualifier object.
*
* @param session
*/
public SelectQualifier(ISession session) {
this.session = session;
}
public static PlainSelect qualify(ISession conn, PlainSelect select) {
SelectQualifier q = new SelectQualifier(conn);
select.accept(q);
return q.qualifiedSelect;
}
public PlainSelect getQualifiedQuery() {
if (qualifiedSelect == null) {
throw new IllegalStateException("not created yet");
}
return qualifiedSelect;
}
public void visit(PlainSelect plainSelect) throws IllegalStateException {
qualifiedSelect = new PlainSelect();
@SuppressWarnings("unchecked")
List<FromItem> fromItems = qualifyFromItems(plainSelect.getFromItems());
qualifiedSelect.setFromItems(fromItems);
Map<String, Table> aliases = extractTableAliases(fromItems);
// @todo: REVISIT, looks like a bug here, fromItems is not being read after assigned
fromItems = removeTableAliases(fromItems);
List selectItems = qualifySelectItems(aliases, plainSelect.getSelectItems());
qualifiedSelect.setSelectItems(selectItems);
Expression where = qualifyWhere(aliases, plainSelect.getWhere());
qualifiedSelect.setWhere(where);
List<OrderByElement> orderByItems = qualifyOrderBy(aliases, plainSelect.getOrderByElements());
qualifiedSelect.setOrderByElements(orderByItems);
}
private Map<String, Table> extractTableAliases(List<FromItem> fromItems) {
Map<String, Table> aliases = new HashMap<String, Table>();
for (Iterator<FromItem> it = fromItems.iterator(); it.hasNext();) {
FromItem fromItem = it.next();
if (fromItem instanceof Table) {
Table table = (Table) fromItem;
String alias = table.getAlias();
if (alias != null) {
aliases.put(alias, table);
}
}
}
return aliases;
}
private List<FromItem> removeTableAliases(final List<FromItem> fromItems) {
List<FromItem> items = new ArrayList<FromItem>(fromItems);
for (Iterator<FromItem> it = items.iterator(); it.hasNext();) {
FromItem fromItem = it.next();
if (fromItem instanceof Table) {
Table table = (Table) fromItem;
table.setAlias(null);
}
}
return items;
}
private Expression qualifyWhere(Map tableAliases, Expression where) {
if (where == null) {
return null;
}
Expression qualifiedWhere = ExpressionQualifier.qualify(session, tableAliases, where);
return qualifiedWhere;
}
private List<OrderByElement> qualifyOrderBy(Map tableAliases, List orderByElements) {
if (orderByElements == null) {
return null;
}
List<OrderByElement> qualifiedOrderElems = new ArrayList<OrderByElement>();
for (Iterator it = orderByElements.iterator(); it.hasNext();) {
OrderByElement orderByElem = (OrderByElement) it.next();
OrderByElement qualified = OrderByElementQualifier.qualify(session, tableAliases,
orderByElem);
qualifiedOrderElems.add(qualified);
}
return qualifiedOrderElems;
}
private List qualifySelectItems(Map tableAlias, List selectItems) {
if (selectItems == null) {
return null;
}
List qualifiedItems = new ArrayList();
for (Iterator it = selectItems.iterator(); it.hasNext();) {
SelectItem selectItem = (SelectItem) it.next();
List items = SelectItemQualifier.qualify(session, tableAlias, selectItem);
qualifiedItems.addAll(items);
}
return qualifiedItems;
}
private List<FromItem> qualifyFromItems(List fromItems) {
if (fromItems == null) {
return null;
}
List<FromItem> qualifiedFromItems = new ArrayList<FromItem>();
for (Iterator it = fromItems.iterator(); it.hasNext();) {
FromItem fromItem = (FromItem) it.next();
FromItem qualifiedItem = FromItemQualifier.qualify(session, fromItem);
qualifiedFromItems.add(qualifiedItem);
}
return qualifiedFromItems;
}
public void visit(Union union) {
throw new UnsupportedOperationException();
}
}