org.apache.openjpa.jdbc.meta.strats.ElementEmbedValueHandler Maven / Gradle / Ivy
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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
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* 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.*;
import java.util.*;
import org.apache.openjpa.lib.util.*;
import org.apache.openjpa.kernel.*;
import org.apache.openjpa.util.*;
import org.apache.openjpa.jdbc.meta.*;
import org.apache.openjpa.jdbc.identifier.DBIdentifier;
import org.apache.openjpa.jdbc.kernel.*;
import org.apache.openjpa.jdbc.schema.*;
import org.apache.openjpa.jdbc.sql.DBDictionary;
/**
* Handler for embedded objects as elements of a collection or map. For
* embedded objects as fields, use the more powerful
* {@link EmbedFieldStrategy}.
*
* @author Abe White
* @since 0.4.0, 1.1.0
* @nojavadoc
*/
public class ElementEmbedValueHandler
extends EmbedValueHandler
implements RelationId {
private static final Localizer _loc = Localizer.forPackage
(ElementEmbedValueHandler.class);
private ValueMapping _vm = null;
private Column[] _cols = null;
private Object[] _args = null;
private int _nullIdx = -1;
private boolean _synthetic = false;
/**
* @deprecated
*/
public Column[] map(ValueMapping vm, String name, ColumnIO io,
boolean adapt) {
DBDictionary dict = vm.getMappingRepository().getDBDictionary();
DBIdentifier colName = DBIdentifier.newColumn(name, dict != null ? dict.delimitAll() : false);
return map(vm, colName, io, adapt);
}
public Column[] map(ValueMapping vm, DBIdentifier name, ColumnIO io,
boolean adapt) {
LinkedList cols = new LinkedList();
LinkedList args = new LinkedList();
super.map(vm, name, io, adapt, cols, args);
ValueMappingInfo vinfo = vm.getValueInfo();
Column nullInd = vinfo.getNullIndicatorColumn(vm, name,
vm.getFieldMapping().getTable(), adapt);
if (nullInd != null)
vm.setColumns(new Column[]{ nullInd });
// record index of null indicator column and whether it is synthetic
if (nullInd != null) {
_nullIdx = cols.indexOf(nullInd);
if (_nullIdx == -1) {
cols.addFirst(nullInd);
args.addFirst(null);
_nullIdx = 0;
_synthetic = true;
}
}
_vm = vm;
_cols = (Column[]) cols.toArray(new Column[cols.size()]);
_args = args.toArray();
return _cols;
}
public boolean objectValueRequiresLoad(ValueMapping vm) {
return true;
}
public Object getResultArgument(ValueMapping vm) {
return _args;
}
public Object toDataStoreValue(ValueMapping vm, Object val,
JDBCStore store) {
OpenJPAStateManager em = store.getContext().getStateManager(val);
Object rval = null;
if (_cols.length > 1)
rval = new Object[_cols.length];
// set null indicator column
int idx = 0;
if (_synthetic) {
Object cval = ((EmbeddedClassStrategy) vm.getEmbeddedMapping().
getStrategy()).getNullIndicatorValue(em);
if (_cols.length == 1)
return cval;
((Object[]) rval)[idx++] = cval;
}
return super.toDataStoreValue(em, vm, store, _cols, rval, idx);
}
public Object toObjectValue(ValueMapping vm, Object val,
OpenJPAStateManager sm, JDBCStore store, JDBCFetchConfiguration fetch)
throws SQLException {
// check null indicator first
if (_nullIdx != -1) {
Object nval;
if (_cols.length == 1)
nval = val;
else
nval = ((Object[]) val)[_nullIdx];
if (((EmbeddedClassStrategy) vm.getEmbeddedMapping().
getStrategy()).indicatesNull(nval))
return null;
}
// create embedded instance
OpenJPAStateManager em = store.getContext().embed(null, null, sm, vm);
int idx = (_synthetic) ? 1 : 0;
super.toObjectValue(em, vm, val, store, fetch, _cols, idx);
// after loading everything from result, load the rest of the
// configured fields
em.load(fetch);
return em.getManagedInstance();
}
/////////////////////////////
// RelationId implementation
/////////////////////////////
public Object toRelationDataStoreValue(OpenJPAStateManager sm, Column col) {
return toRelationDataStoreValue(sm, col, 0);
}
/**
* Recursive helper.
*/
private Object toRelationDataStoreValue(OpenJPAStateManager sm, Column col,
int idx) {
FieldMapping field = findField(col, idx);
if (field == null)
throw new InternalException();
if (field.getHandler() instanceof RelationId)
return ((RelationId) field.getStrategy()).
toRelationDataStoreValue(sm, col);
if (field.getStrategy() instanceof RelationId)
return ((RelationId) field.getStrategy()).
toRelationDataStoreValue(sm, col);
return toRelationDataStoreValue(sm, col, field.getIndex() + 1);
}
/**
* Find the first field mapping that uses the given column starting with
* the given field index.
*/
private FieldMapping findField(Column col, int idx) {
FieldMapping[] fms = _vm.getEmbeddedMapping().getFieldMappings();
Column[] cols;
for (int i = idx; i < fms.length; i++) {
if (fms[i].getManagement() != FieldMapping.MANAGE_PERSISTENT)
continue;
cols = ((Embeddable) fms[i]).getColumns();
for (int j = 0; j < cols.length; j++)
if (cols[j] == col)
return fms[i];
}
return null;
}
}