/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.openjpa.jdbc.kernel.exps;
import java.sql.SQLException;
import org.apache.openjpa.jdbc.meta.ClassMapping;
import org.apache.openjpa.jdbc.meta.Discriminator;
import org.apache.openjpa.jdbc.sql.Result;
import org.apache.openjpa.jdbc.sql.SQLBuffer;
import org.apache.openjpa.jdbc.sql.Select;
import org.apache.openjpa.kernel.exps.Path;
import org.apache.openjpa.util.InternalException;
/**
* Entity Type expression.
*
* @author Catalina Wei
* @since 2.0.0
*/
class Type
extends UnaryOp {
Discriminator _disc = null;
public Type(Val val) {
super(val);
setMetaData(val.getMetaData());
if (getMetaData() != null)
_disc = ((ClassMapping) getMetaData()).getDiscriminator();
}
public ExpState initialize(Select sel, ExpContext ctx, int flags) {
return initializeValue(sel, ctx, flags);
}
public Object load(ExpContext ctx, ExpState state, Result res)
throws SQLException {
Object type = null;
if (_disc != null && _disc.getColumns().length > 0) {
type = res.getObject(_disc.getColumns()[0], null, state.joins);
ClassMapping sup = (ClassMapping) getMetaData();
ClassMapping[] subs = sup.getMappedPCSubclassMappings();
for (ClassMapping sub : subs) {
if (sub.getDiscriminator().getValue().equals(type))
return sub.getDescribedType();
}
}
else
type = getValue().load(ctx, state, res);
return type.getClass();
}
public void calculateValue(Select sel, ExpContext ctx, ExpState state,
Val other, ExpState otherState) {
super.calculateValue(sel, ctx, state, null, null);
}
public void select(Select sel, ExpContext ctx, ExpState state,
boolean pks) {
if (_disc != null && _disc.getColumns().length > 0)
sel.select(_disc.getColumns(), state.joins);
else
getValue().select(sel, ctx, state, pks);
}
public void appendTo(Select sel, ExpContext ctx, ExpState state,
SQLBuffer sql, int index) {
getValue().calculateValue(sel, ctx, state, null, null);
getValue().appendType(sel, ctx, state, sql);
sel.append(sql, state.joins);
}
protected Class getType(Class c) {
return Class.class;
}
protected String getOperator() {
// since we override appendTo(), this method should never be called
throw new InternalException();
}
public Path getPath() {
return getValue() instanceof Path ? (Path) getValue() : null;
}
public Discriminator getDiscriminator() {
return _disc;
}
}