/*
* 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.meta.strats;
import java.sql.SQLException;
import java.util.Collection;
import java.util.Map;
import org.apache.openjpa.conf.OpenJPAConfiguration;
import org.apache.openjpa.jdbc.kernel.JDBCFetchConfiguration;
import org.apache.openjpa.jdbc.kernel.JDBCStore;
import org.apache.openjpa.jdbc.meta.ClassMapping;
import org.apache.openjpa.jdbc.meta.FieldMapping;
import org.apache.openjpa.jdbc.meta.ValueMapping;
import org.apache.openjpa.jdbc.schema.Column;
import org.apache.openjpa.jdbc.schema.ForeignKey;
import org.apache.openjpa.jdbc.sql.Joins;
import org.apache.openjpa.jdbc.sql.Result;
import org.apache.openjpa.jdbc.sql.Select;
import org.apache.openjpa.jdbc.sql.Union;
import org.apache.openjpa.kernel.OpenJPAStateManager;
import org.apache.openjpa.lib.util.Localizer;
import org.apache.openjpa.meta.JavaTypes;
import org.apache.openjpa.util.InternalException;
import org.apache.openjpa.util.MetaDataException;
import org.apache.openjpa.util.Proxy;
/**
* Uses an association table to hold map values. Derives map keys from
* a field in each value.
*
* @author Abe White
*/
public class RelationMapTableFieldStrategy
extends RelationToManyTableFieldStrategy
implements LRSMapFieldStrategy {
private static final Localizer _loc = Localizer.forPackage
(RelationMapTableFieldStrategy.class);
public FieldMapping getFieldMapping() {
return field;
}
public ClassMapping[] getIndependentKeyMappings(boolean traverse) {
return ClassMapping.EMPTY_MAPPINGS;
}
public ClassMapping[] getIndependentValueMappings(boolean traverse) {
return getIndependentElementMappings(traverse);
}
public ForeignKey getJoinForeignKey(ClassMapping cls) {
return super.getJoinForeignKey(cls);
}
public Column[] getKeyColumns(ClassMapping cls) {
return cls.getFieldMapping(field.getKey().
getValueMappedByMetaData().getIndex()).getColumns();
}
public Column[] getValueColumns(ClassMapping cls) {
return field.getElementMapping().getColumns();
}
public void selectKey(Select sel, ClassMapping key, OpenJPAStateManager sm,
JDBCStore store, JDBCFetchConfiguration fetch, Joins joins) {
throw new InternalException();
}
public Object loadKey(OpenJPAStateManager sm, JDBCStore store,
JDBCFetchConfiguration fetch, Result res, Joins joins)
throws SQLException {
throw new InternalException();
}
public Object deriveKey(JDBCStore store, Object value) {
OpenJPAStateManager sm = RelationStrategies.getStateManager(value,
store.getContext());
return (sm == null) ? null : sm.fetchField(field.getKey().
getValueMappedByMetaData().getIndex(), false);
}
public Object deriveValue(JDBCStore store, Object key) {
return null;
}
public void selectValue(Select sel, ClassMapping val,
OpenJPAStateManager sm, JDBCStore store, JDBCFetchConfiguration fetch,
Joins joins) {
selectElement(sel, val, store, fetch, JDBCFetchConfiguration.EAGER_NONE,
joins);
}
public Object loadValue(OpenJPAStateManager sm, JDBCStore store,
JDBCFetchConfiguration fetch, Result res, Joins joins)
throws SQLException {
return loadElement(sm, store, fetch, res, joins);
}
public Result[] getResults(final OpenJPAStateManager sm,
final JDBCStore store, final JDBCFetchConfiguration fetch,
final int eagerMode, final Joins[] joins, boolean lrs)
throws SQLException {
ValueMapping val = field.getElementMapping();
final ClassMapping[] vals = val.getIndependentTypeMappings();
Union union = store.getSQLFactory().newUnion(vals.length);
if (fetch.getSubclassFetchMode(val.getTypeMapping())
!= JDBCFetchConfiguration.EAGER_JOIN)
union.abortUnion();
union.setLRS(lrs);
union.select(new Union.Selector() {
public void select(Select sel, int idx) {
joins[1] = selectAll(sel, vals[idx], sm, store, fetch,
eagerMode);
}
});
Result res = union.execute(store, fetch);
return new Result[]{ res, res };
}
public Joins joinKeyRelation(Joins joins, ClassMapping key) {
return joins;
}
public Joins joinValueRelation(Joins joins, ClassMapping val) {
return joinElementRelation(joins, val);
}
protected Proxy newLRSProxy() {
return new LRSProxyMap(this);
}
protected void add(JDBCStore store, Object coll, Object obj) {
if (obj != null)
((Map) coll).put(deriveKey(store, obj), obj);
}
protected Collection toCollection(Object val) {
return (val == null) ? null : ((Map) val).values();
}
public void map(boolean adapt) {
if (field.getTypeCode() != JavaTypes.MAP)
throw new MetaDataException(_loc.get("not-map", field));
if (field.getKey().getValueMappedBy() == null)
throw new MetaDataException(_loc.get("not-mapped-by-key", field));
super.map(adapt);
}
public Joins joinKey(Joins joins, boolean forceOuter) {
return joinRelation(join(joins, forceOuter), forceOuter, false);
}
}