org.eclipse.persistence.mappings.structures.ReferenceMapping Maven / Gradle / Ivy
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/*
* Copyright (c) 1998, 2021 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0 which is available at
* http://www.eclipse.org/legal/epl-2.0,
* or the Eclipse Distribution License v. 1.0 which is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
*/
// Contributors:
// Oracle - initial API and implementation from Oracle TopLink
package org.eclipse.persistence.mappings.structures;
import java.sql.Ref;
import java.sql.Struct;
import java.util.Map;
import java.util.Vector;
import org.eclipse.persistence.exceptions.DatabaseException;
import org.eclipse.persistence.exceptions.DescriptorException;
import org.eclipse.persistence.exceptions.OptimisticLockException;
import org.eclipse.persistence.exceptions.QueryException;
import org.eclipse.persistence.expressions.Expression;
import org.eclipse.persistence.indirection.ValueHolder;
import org.eclipse.persistence.internal.expressions.ObjectExpression;
import org.eclipse.persistence.internal.helper.DatabaseField;
import org.eclipse.persistence.internal.helper.DatabaseTable;
import org.eclipse.persistence.internal.identitymaps.CacheKey;
import org.eclipse.persistence.internal.queries.JoinedAttributeManager;
import org.eclipse.persistence.internal.sessions.AbstractRecord;
import org.eclipse.persistence.internal.sessions.AbstractSession;
import org.eclipse.persistence.internal.sessions.ChangeRecord;
import org.eclipse.persistence.internal.sessions.ObjectChangeSet;
import org.eclipse.persistence.internal.sessions.ObjectReferenceChangeRecord;
import org.eclipse.persistence.internal.sessions.UnitOfWorkChangeSet;
import org.eclipse.persistence.internal.sessions.UnitOfWorkImpl;
import org.eclipse.persistence.mappings.ObjectReferenceMapping;
import org.eclipse.persistence.queries.DeleteObjectQuery;
import org.eclipse.persistence.queries.InsertObjectQuery;
import org.eclipse.persistence.queries.ObjectBuildingQuery;
import org.eclipse.persistence.queries.QueryByExamplePolicy;
import org.eclipse.persistence.queries.WriteObjectQuery;
import org.eclipse.persistence.sessions.DatabaseRecord;
/**
* Purpose:
* In an object-relational data model, structures reference each other through "Refs"; not through foreign keys as
* in the relational data model. TopLink supports using the Ref to reference the target object.
*/
public class ReferenceMapping extends ObjectReferenceMapping {
/** A ref is always stored in a single field. */
protected DatabaseField field;
public ReferenceMapping() {
super();
this.setWeight(WEIGHT_AGGREGATE);
}
/**
* INTERNAL:
* In case Query By Example is used, this method builds and returns an expression that
* corresponds to a single attribute and it's value.
*/
@Override
public Expression buildExpression(Object queryObject, QueryByExamplePolicy policy, Expression expressionBuilder, Map processedObjects, AbstractSession session) {
if (policy.shouldValidateExample()){
throw QueryException.unsupportedMappingQueryByExample(queryObject.getClass().getName(), this);
}
return null;
}
/**
* Returns all the aggregate fields.
*/
@Override
protected Vector collectFields() {
Vector fields = new Vector(1);
fields.addElement(getField());
return fields;
}
/**
* INTERNAL:
* Returns the field which this mapping represents.
*/
@Override
public DatabaseField getField() {
return field;
}
/**
* PUBLIC:
* Return the name of the field this mapping represents.
*/
public String getFieldName() {
return getField().getName();
}
/**
* INTERNAL:
* Join criteria is created to read target records (nested table) from the table.
*/
@Override
public Expression getJoinCriteria(ObjectExpression context, Expression base) {
return null;
}
/**
* INTERNAL:
* The returns if the mapping has any constraint dependencies, such as foreign keys and join tables.
*/
@Override
public boolean hasConstraintDependency() {
return true;
}
/**
* INTERNAL:
* Initialize the mapping.
*/
@Override
public void initialize(AbstractSession session) throws DescriptorException {
setReferenceDescriptor(session.getDescriptor(getReferenceClass()));
if (referenceDescriptor == null) {
throw DescriptorException.descriptorIsMissing(getReferenceClass().getName(), this);
}
// For bug 2730536 convert the field to be an ObjectRelationalDatabaseField.
ObjectRelationalDatabaseField field = (ObjectRelationalDatabaseField)getField();
field.setSqlType(java.sql.Types.REF);
if (referenceDescriptor instanceof ObjectRelationalDataTypeDescriptor) {
field.setSqlTypeName(((ObjectRelationalDataTypeDescriptor)referenceDescriptor).getStructureName());
}
setField(getDescriptor().buildField(getField()));
setFields(collectFields());
// Ref mapping requires native connection in WLS as the Ref is wrapped.
getDescriptor().setIsNativeConnectionRequired(true);
}
/**
* INTERNAL:
*/
@Override
public boolean isReferenceMapping() {
return true;
}
/**
* INTERNAL:
* Insert privately owned parts
*/
@Override
public void preInsert(WriteObjectQuery query) throws DatabaseException, OptimisticLockException {
// Checks if privately owned parts should be inserted or not.
if (!shouldObjectModifyCascadeToParts(query)) {
return;
}
// Get the privately owned parts
Object object = getRealAttributeValueFromObject(query.getObject(), query.getSession());
if (object == null) {
return;
}
if (isPrivateOwned()) {
// No need to set changeSet as insert is a straight copy anyway
InsertObjectQuery insertQuery = new InsertObjectQuery();
insertQuery.setIsExecutionClone(true);
insertQuery.setObject(object);
insertQuery.setCascadePolicy(query.getCascadePolicy());
query.getSession().executeQuery(insertQuery);
} else {
ObjectChangeSet changeSet = null;
UnitOfWorkChangeSet uowChangeSet = null;
if (query.getSession().isUnitOfWork() && (((UnitOfWorkImpl)query.getSession()).getUnitOfWorkChangeSet() != null)) {
uowChangeSet = (UnitOfWorkChangeSet)((UnitOfWorkImpl)query.getSession()).getUnitOfWorkChangeSet();
changeSet = (ObjectChangeSet)uowChangeSet.getObjectChangeSetForClone(object);
}
WriteObjectQuery writeQuery = new WriteObjectQuery();
writeQuery.setIsExecutionClone(true);
writeQuery.setObject(object);
writeQuery.setObjectChangeSet(changeSet);
writeQuery.setCascadePolicy(query.getCascadePolicy());
query.getSession().executeQuery(writeQuery);
}
}
/**
* INTERNAL:
* Update privately owned parts
*/
@Override
public void preUpdate(WriteObjectQuery query) throws DatabaseException, OptimisticLockException {
if (!isAttributeValueInstantiated(query.getObject())) {
return;
}
if (isPrivateOwned()) {
Object objectInDatabase = readPrivateOwnedForObject(query);
if (objectInDatabase != null) {
query.setProperty(this, objectInDatabase);
}
}
if (!shouldObjectModifyCascadeToParts(query)) {
return;
}
// Get the privately owned parts in the memory
Object object = getRealAttributeValueFromObject(query.getObject(), query.getSession());
if (object != null) {
ObjectChangeSet changeSet = null;
UnitOfWorkChangeSet uowChangeSet = null;
if (query.getSession().isUnitOfWork() && (((UnitOfWorkImpl)query.getSession()).getUnitOfWorkChangeSet() != null)) {
uowChangeSet = (UnitOfWorkChangeSet)((UnitOfWorkImpl)query.getSession()).getUnitOfWorkChangeSet();
changeSet = (ObjectChangeSet)uowChangeSet.getObjectChangeSetForClone(object);
}
WriteObjectQuery writeQuery = new WriteObjectQuery();
writeQuery.setIsExecutionClone(true);
writeQuery.setObject(object);
writeQuery.setObjectChangeSet(changeSet);
writeQuery.setCascadePolicy(query.getCascadePolicy());
query.getSession().executeQuery(writeQuery);
}
}
/**
* INTERNAL:
* Insert privately owned parts
*/
@Override
public void postInsert(WriteObjectQuery query) throws DatabaseException, OptimisticLockException {
return;
}
/**
* INTERNAL:
* Delete privately owned parts
*/
@Override
public void postDelete(DeleteObjectQuery query) throws DatabaseException, OptimisticLockException {
return;
}
/**
* INTERNAL:
* Update privately owned parts
*/
@Override
public void postUpdate(WriteObjectQuery query) throws DatabaseException, OptimisticLockException {
return;
}
/**
* INTERNAL:
* Delete privately owned parts
*/
@Override
public void preDelete(DeleteObjectQuery query) throws DatabaseException, OptimisticLockException {
return;
}
/**
* Set the field in the mapping.
*/
protected void setField(DatabaseField field) {
this.field = field;
}
/**
* PUBLIC:
* Set the field name in the mapping.
*/
public void setFieldName(String fieldName) {
setField(new ObjectRelationalDatabaseField(fieldName));
}
/**
* PUBLIC:
* This is a reference class whose instances this mapping will store in the domain objects.
*/
@Override
public void setReferenceClass(Class referenceClass) {
this.referenceClass = referenceClass;
}
/**
* INTERNAL:
* Return the value of the field from the row or a value holder on the query to obtain the object.
* Check for batch + aggregation reading.
*/
@Override
public Object valueFromRow(AbstractRecord row, JoinedAttributeManager joinManager, ObjectBuildingQuery query, CacheKey cacheKey, AbstractSession executionSession, boolean isTargetProtected, Boolean[] wasCacheUsed) throws DatabaseException {
if (this.descriptor.getCachePolicy().isProtectedIsolation()) {
if (this.isCacheable && isTargetProtected && cacheKey != null) {
//cachekey will be null when isolating to uow
//used cached collection
Object result = null;
Object cached = cacheKey.getObject();
if (cached != null) {
if (wasCacheUsed != null){
wasCacheUsed[0] = Boolean.TRUE;
}
return this.getAttributeValueFromObject(cached);
}
return result;
} else if (!this.isCacheable && !isTargetProtected && cacheKey != null) {
return this.indirectionPolicy.buildIndirectObject(new ValueHolder<>(null));
}
}
AbstractRecord targetRow = null;
if (row.hasSopObject()) {
Object sopAttributeValue = getAttributeValueFromObject(row.getSopObject());
if (sopAttributeValue == null) {
return this.indirectionPolicy.nullValueFromRow();
}
// As part of SOP object the indirection should be already triggered
Object sopRealAttributeValue = getIndirectionPolicy().getRealAttributeValueFromObject(row.getSopObject(), sopAttributeValue);
if (sopRealAttributeValue == null) {
return sopAttributeValue;
}
targetRow = new DatabaseRecord(0);
targetRow.setSopObject(sopRealAttributeValue);
// As part of SOP object the indirection should be already triggered and should be no references outside of sopObject (and its privately owned (possibly nested privately owned) objects)
return getReferenceDescriptor().getObjectBuilder().buildObject(query, targetRow, null);
}
Ref ref = (Ref)row.get(getField());
if (ref == null) {
return null;
}
Struct struct;
try {
executionSession.getAccessor().incrementCallCount(executionSession);
java.sql.Connection connection = executionSession.getAccessor().getConnection();
struct = (Struct)executionSession.getPlatform().getRefValue(ref,executionSession,connection);
targetRow = ((ObjectRelationalDataTypeDescriptor)getReferenceDescriptor()).buildRowFromStructure(struct);
} catch (java.sql.SQLException exception) {
throw DatabaseException.sqlException(exception, executionSession, false);
} finally {
executionSession.getAccessor().decrementCallCount();
}
return getReferenceDescriptor().getObjectBuilder().buildObject(query, targetRow, joinManager);
}
/**
* INTERNAL:
* Get a value from the object and set that in the respective field of the row.
*/
@Override
public void writeFromObjectIntoRow(Object object, AbstractRecord record, AbstractSession session, WriteType writeType) {
if (isReadOnly()) {
return;
}
writeFromObjectIntoRowInternal(object, record, session, false);
}
/**
* INTERNAL:
* Get a value from the object and set that in the respective field of the row.
*/
public void writeFromObjectIntoRowInternal(Object object, AbstractRecord record, AbstractSession session, boolean shouldIgnoreNull) {
Object referenceObject = getRealAttributeValueFromObject(object, session);
if (referenceObject == null) {
if (!shouldIgnoreNull) {
// Fix for 2730536, must put something in modify row, even if it is null.
record.put(getField(), null);
}
return;
}
Ref ref = ((ObjectRelationalDataTypeDescriptor)getReferenceDescriptor()).getRef(referenceObject, session);
record.put(getField(), ref);
}
/**
* INTERNAL:
* Get a value from the object and set that in the respective field of the row.
*/
@Override
public void writeFromObjectIntoRowWithChangeRecord(ChangeRecord changeRecord, AbstractRecord record, AbstractSession session, WriteType writeType) {
if (isReadOnly()) {
return;
}
ObjectChangeSet changeSet = (ObjectChangeSet)((ObjectReferenceChangeRecord)changeRecord).getNewValue();
Object referenceObject = changeSet.getUnitOfWorkClone();
if (referenceObject == null) {
return;
}
Ref ref = ((ObjectRelationalDataTypeDescriptor)getReferenceDescriptor()).getRef(referenceObject, session);
record.put(getField(), ref);
}
/**
* INTERNAL:
* This row is built for shallow insert which happens in case of bidirectional inserts.
* The foreign keys must be set to null to avoid constraints.
*/
@Override
public void writeFromObjectIntoRowForShallowInsert(Object object, AbstractRecord record, AbstractSession session) {
if (isReadOnly()) {
return;
}
if (getField().isNullable()) {
record.put(getField(), null);
} else {
writeFromObjectIntoRowInternal(object, record, session, false);
}
}
/**
* INTERNAL:
* This row is built for update after shallow insert which happens in case of bidirectional inserts.
* It contains the foreign keys with non null values that were set to null for shallow insert.
*/
@Override
public void writeFromObjectIntoRowForUpdateAfterShallowInsert(Object object, AbstractRecord record, AbstractSession session, DatabaseTable table) {
if (this.isReadOnly) {
return;
}
if (!getField().getTable().equals(table) || !getField().isNullable()) {
return;
}
writeFromObjectIntoRowInternal(object, record, session, true);
}
/**
* INTERNAL:
* This row is built for shallow insert which happens in case of bidirectional inserts.
* The foreign keys must be set to null to avoid constraints.
*/
@Override
public void writeFromObjectIntoRowForShallowInsertWithChangeRecord(ChangeRecord changeRecord, AbstractRecord record, AbstractSession session) {
if (isReadOnly()) {
return;
}
record.put(getField(), null);
}
/**
* INTERNAL:
* Write fields needed for insert into the template for with null values.
*/
@Override
public void writeInsertFieldsIntoRow(AbstractRecord record, AbstractSession session) {
if (isReadOnly()) {
return;
}
record.put(getField(), null);
}
/**
* INTERNAL:
*/
@Override
public boolean isRelationalMapping() {
return true;
}
}