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* Licensed to the Apache Software Foundation (ASF) under one
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* 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
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package org.apache.cayenne.access.jdbc;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import org.apache.cayenne.DataRow;
import org.apache.cayenne.access.trans.SelectTranslator;
import org.apache.cayenne.access.types.ExtendedType;
import org.apache.cayenne.dba.TypesMapping;
import org.apache.cayenne.map.Entity;
import org.apache.cayenne.map.EntityInheritanceTree;
import org.apache.cayenne.map.ObjAttribute;
import org.apache.cayenne.map.ObjEntity;
/**
* Deals with DataRow type conversion in inheritance situations.
*
* @since 1.2
*/
class DataRowPostProcessor {
private EntityInheritanceTree inheritanceTree;
private Map<String, Collection<ColumnOverride>> columnOverrides;
private Collection<ColumnOverride> defaultOverrides;
// factory method
static DataRowPostProcessor createPostProcessor(SelectTranslator translator) {
Map attributeOverrides = translator.getAttributeOverrides();
if (attributeOverrides.isEmpty()) {
return null;
}
ColumnDescriptor[] columns = translator.getResultColumns();
Map<String, Collection<ColumnOverride>> columnOverrides = new HashMap<String, Collection<ColumnOverride>>(2);
Iterator it = attributeOverrides.entrySet().iterator();
while (it.hasNext()) {
Map.Entry entry = (Map.Entry) it.next();
ObjAttribute attribute = (ObjAttribute) entry.getKey();
Entity entity = attribute.getEntity();
String key = null;
int jdbcType = TypesMapping.NOT_DEFINED;
int index = -1;
for (int i = 0; i < columns.length; i++) {
if (columns[i] == entry.getValue()) {
// if attribute type is the same as column, there is no conflict
if (!attribute.getType().equals(columns[i].getJavaClass())) {
// note that JDBC index is "1" based
index = i + 1;
jdbcType = columns[i].getJdbcType();
key = columns[i].getLabel();
}
break;
}
}
if (index < 1) {
continue;
}
ExtendedType converter = translator
.getAdapter()
.getExtendedTypes()
.getRegisteredType(attribute.getType());
Collection<ColumnOverride> overrides = columnOverrides.get(entity.getName());
if (overrides == null) {
overrides = new ArrayList<ColumnOverride>(3);
columnOverrides.put(entity.getName(), overrides);
}
overrides.add(new ColumnOverride(index, key, converter, jdbcType));
}
// inject null post-processor
return columnOverrides.isEmpty() ? null : new DataRowPostProcessor(translator
.getRootInheritanceTree(), columnOverrides);
}
private DataRowPostProcessor(EntityInheritanceTree inheritanceTree,
Map<String, Collection<ColumnOverride>> columnOverrides) {
if (inheritanceTree != null && inheritanceTree.getChildren().size() > 0) {
this.inheritanceTree = inheritanceTree;
this.columnOverrides = columnOverrides;
}
else {
if (columnOverrides.size() != 1) {
throw new IllegalArgumentException(
"No inheritance - there must be only one override set");
}
defaultOverrides = columnOverrides.values().iterator().next();
}
}
void postprocessRow(ResultSet resultSet, DataRow row) throws Exception {
Collection<ColumnOverride> overrides = getOverrides(row);
if (overrides != null) {
for (final ColumnOverride override : overrides) {
Object newValue = override.converter.materializeObject(
resultSet,
override.index,
override.jdbcType);
row.put(override.key, newValue);
}
}
}
private final Collection<ColumnOverride> getOverrides(DataRow row) {
if (defaultOverrides != null) {
return defaultOverrides;
}
else {
ObjEntity entity = inheritanceTree.entityMatchingRow(row);
return entity != null
? columnOverrides.get(entity.getName())
: null;
}
}
static final class ColumnOverride {
int index;
int jdbcType;
String key;
ExtendedType converter;
ColumnOverride(int index, String key, ExtendedType converter, int jdbcType) {
this.index = index;
this.key = key;
this.converter = converter;
this.jdbcType = jdbcType;
}
}
}