| /* |
| * 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.internal.indirection; |
| |
| import java.lang.reflect.Constructor; |
| import java.security.AccessController; |
| import java.security.PrivilegedActionException; |
| |
| import org.eclipse.persistence.exceptions.DescriptorException; |
| import org.eclipse.persistence.indirection.IndirectContainer; |
| import org.eclipse.persistence.indirection.ValueHolder; |
| import org.eclipse.persistence.indirection.ValueHolderInterface; |
| import org.eclipse.persistence.internal.descriptors.DescriptorIterator; |
| import org.eclipse.persistence.internal.helper.ClassConstants; |
| import org.eclipse.persistence.internal.identitymaps.CacheKey; |
| import org.eclipse.persistence.internal.security.PrivilegedAccessHelper; |
| import org.eclipse.persistence.internal.security.PrivilegedGetConstructorFor; |
| import org.eclipse.persistence.internal.security.PrivilegedInvokeConstructor; |
| import org.eclipse.persistence.internal.sessions.AbstractRecord; |
| import org.eclipse.persistence.internal.sessions.AbstractSession; |
| import org.eclipse.persistence.internal.sessions.UnitOfWorkImpl; |
| import org.eclipse.persistence.internal.sessions.remote.RemoteSessionController; |
| import org.eclipse.persistence.internal.sessions.remote.RemoteUnitOfWork; |
| import org.eclipse.persistence.queries.ObjectLevelReadQuery; |
| import org.eclipse.persistence.queries.ReadQuery; |
| |
| /** |
| * <b>Purpose</b>: Provide ability for developers to wrap ValueHolders (Basic Indirection)<p> |
| * <b>Responsibilities</b>:<ul> |
| * <li>Wrap & un-wrap a ValueHolder within an IndirectContainer |
| * <li>Reflectively instantiate the containers as required |
| * </ul> |
| * @see org.eclipse.persistence.indirection.IndirectContainer |
| * @author Doug Clarke (TOP) |
| * @since 2.5.0.5 |
| */ |
| public class ContainerIndirectionPolicy extends BasicIndirectionPolicy { |
| private Class containerClass; |
| private String containerClassName; |
| private transient Constructor containerConstructor; |
| |
| /** |
| * INTERNAL: |
| * Construct a new indirection policy. |
| */ |
| public ContainerIndirectionPolicy() { |
| super(); |
| } |
| |
| /** |
| * INTERNAL: |
| * Return a backup clone of the attribute. |
| */ |
| @Override |
| public Object backupCloneAttribute(Object attributeValue, Object clone, Object backup, UnitOfWorkImpl unitOfWork) { |
| IndirectContainer container = (IndirectContainer)attributeValue; |
| ValueHolderInterface valueHolder = container.getValueHolder(); |
| ValueHolderInterface newValueHolder = (ValueHolderInterface)super.backupCloneAttribute(valueHolder, clone, backup, unitOfWork); |
| return buildContainer(newValueHolder); |
| } |
| |
| /** |
| * Build a container with the initialized constructor. |
| */ |
| protected IndirectContainer buildContainer(ValueHolderInterface valueHolder) { |
| try { |
| IndirectContainer container = null; |
| if (getContainerConstructor().getParameterTypes().length == 0) { |
| if (PrivilegedAccessHelper.shouldUsePrivilegedAccess()){ |
| container = (IndirectContainer)AccessController.doPrivileged(new PrivilegedInvokeConstructor(getContainerConstructor(), new Object[0])); |
| }else{ |
| container = (IndirectContainer)PrivilegedAccessHelper.invokeConstructor(getContainerConstructor(), new Object[0]); |
| } |
| container.setValueHolder(valueHolder); |
| } else { |
| if (PrivilegedAccessHelper.shouldUsePrivilegedAccess()){ |
| container = (IndirectContainer)AccessController.doPrivileged(new PrivilegedInvokeConstructor(getContainerConstructor(), new Object[] { valueHolder })); |
| }else{ |
| container = (IndirectContainer)PrivilegedAccessHelper.invokeConstructor(getContainerConstructor(), new Object[] { valueHolder }); |
| } |
| } |
| return container; |
| } catch (Exception exception) { |
| throw DescriptorException.invalidIndirectionPolicyOperation(this, "buildContainer constructor (" + getContainerConstructor() + ") Failed: " + exception); |
| } |
| } |
| |
| /** |
| * INTERNAL: This method can be used when an Indirection Object is required |
| * to be built from a provided ValueHolderInterface object. This may be used |
| * for custom value holder types. Certain policies like the |
| * TransparentIndirectionPolicy may wrap the valueholder in another object. |
| */ |
| |
| @Override |
| public Object buildIndirectObject(ValueHolderInterface valueHolder){ |
| return buildContainer(valueHolder); |
| } |
| |
| /** |
| * INTERNAL: |
| * Return a clone of the attribute. |
| * @param buildDirectlyFromRow indicates that we are building the clone directly |
| * from a row as opposed to building the original from the row, putting it in |
| * the shared cache, and then cloning the original. |
| */ |
| @Override |
| public Object cloneAttribute(Object attributeValue, Object original, CacheKey cacheKey, Object clone, Integer refreshCascade, AbstractSession cloningSession, boolean buildDirectlyFromRow) { |
| IndirectContainer container = (IndirectContainer)attributeValue; |
| ValueHolderInterface valueHolder = container.getValueHolder(); |
| ValueHolderInterface newValueHolder = (ValueHolderInterface)super.cloneAttribute(valueHolder, original, cacheKey, clone, refreshCascade, cloningSession, buildDirectlyFromRow); |
| |
| return buildContainer(newValueHolder); |
| } |
| |
| /** |
| * INTERNAL: |
| * Return the reference row for the reference object. |
| * This allows the new row to be built without instantiating |
| * the reference object. |
| * Return null if the object has already been instantiated. |
| */ |
| @Override |
| public AbstractRecord extractReferenceRow(Object referenceObject) { |
| if (this.objectIsInstantiated(referenceObject)) { |
| return null; |
| } else { |
| return ((DatabaseValueHolder)((IndirectContainer)referenceObject).getValueHolder()).getRow(); |
| } |
| } |
| |
| /** |
| * Returns the Container class which implements IndirectContainer. |
| */ |
| public Class getContainerClass() { |
| return containerClass; |
| } |
| |
| /** |
| * INTERNAL: |
| * Used by MW. |
| */ |
| public String getContainerClassName() { |
| if ((containerClassName == null) && (containerClass != null)) { |
| containerClassName = containerClass.getName(); |
| } |
| return containerClassName; |
| } |
| |
| /** |
| * |
| * @return java.lang.reflect.Constructor |
| */ |
| protected Constructor getContainerConstructor() { |
| return containerConstructor; |
| } |
| |
| /** |
| * INTERNAL: |
| * Return the original indirection object for a unit of work indirection object. |
| */ |
| @Override |
| public Object getOriginalIndirectionObject(Object unitOfWorkIndirectionObject, AbstractSession session) { |
| IndirectContainer container = (IndirectContainer)unitOfWorkIndirectionObject; |
| if (container.getValueHolder() instanceof UnitOfWorkValueHolder) { |
| ValueHolderInterface valueHolder = ((UnitOfWorkValueHolder)container.getValueHolder()).getWrappedValueHolder(); |
| if ((valueHolder == null) && session.isRemoteUnitOfWork()) { |
| RemoteSessionController controller = ((RemoteUnitOfWork)session).getParentSessionController(); |
| valueHolder = controller.getRemoteValueHolders().get(((UnitOfWorkValueHolder)container.getValueHolder()).getWrappedValueHolderRemoteID()); |
| } |
| return buildContainer(valueHolder); |
| } else { |
| return container; |
| } |
| } |
| |
| /** |
| * INTERNAL: |
| * Return the original indirection object for a unit of work indirection object. |
| */ |
| @Override |
| public Object getOriginalIndirectionObjectForMerge(Object unitOfWorkIndirectionObject, AbstractSession session) { |
| IndirectContainer container = (IndirectContainer) getOriginalIndirectionObject(unitOfWorkIndirectionObject, session); |
| DatabaseValueHolder holder = (DatabaseValueHolder)container.getValueHolder(); |
| if (holder != null && holder.getSession()!= null){ |
| holder.setSession(session); |
| } |
| return container; |
| } |
| |
| |
| /** |
| * INTERNAL: |
| * Return the "real" attribute value, as opposed to any wrapper. |
| * This will trigger the wrapper to instantiate the value. |
| */ |
| @Override |
| public Object getRealAttributeValueFromObject(Object object, Object attribute) { |
| return ((IndirectContainer)attribute).getValueHolder().getValue(); |
| } |
| |
| /** |
| * INTERNAL: |
| * Ensure the container class implements IndirectContainer and that it |
| * has a constructor which can be used. |
| */ |
| @Override |
| public void initialize() { |
| // Verify that the provided class implements IndirectContainer |
| if (!ClassConstants.IndirectContainer_Class.isAssignableFrom(containerClass)) { |
| throw DescriptorException.invalidIndirectionContainerClass(this, containerClass); |
| } |
| |
| // Try to find constructor which takes a ValueHolderInterface |
| try { |
| if (PrivilegedAccessHelper.shouldUsePrivilegedAccess()){ |
| try{ |
| this.containerConstructor = AccessController.doPrivileged(new PrivilegedGetConstructorFor(getContainerClass(), new Class[] { ClassConstants.ValueHolderInterface_Class }, false)); |
| }catch (PrivilegedActionException ex){ |
| if (ex.getCause() instanceof NoSuchMethodException){ |
| throw (NoSuchMethodException) ex.getCause(); |
| } |
| throw (RuntimeException)ex.getCause(); |
| } |
| }else{ |
| this.containerConstructor = PrivilegedAccessHelper.getConstructorFor(getContainerClass(), new Class[] { ClassConstants.ValueHolderInterface_Class }, false); |
| } |
| return; |
| } catch (NoSuchMethodException nsme) {// DO NOTHING, exception thrown at end |
| } |
| |
| // Try to find the default constructor |
| try { |
| if (PrivilegedAccessHelper.shouldUsePrivilegedAccess()){ |
| try{ |
| this.containerConstructor = AccessController.doPrivileged(new PrivilegedGetConstructorFor(getContainerClass(), new Class[0], false)); |
| }catch (PrivilegedActionException ex){ |
| if (ex.getCause() instanceof NoSuchMethodException){ |
| throw (NoSuchMethodException) ex.getCause(); |
| } |
| throw (RuntimeException)ex.getCause(); |
| } |
| }else{ |
| this.containerConstructor = PrivilegedAccessHelper.getConstructorFor(getContainerClass(), new Class[0], false); |
| } |
| return; |
| } catch (NoSuchMethodException nsme) {// DO NOTHING, exception thrown at end |
| } |
| |
| // If no constructor is found then we throw an initialization exception |
| throw DescriptorException.noConstructorIndirectionContainerClass(this, containerClass); |
| } |
| |
| /** |
| * INTERNAL: |
| * The method validateAttributeOfInstantiatedObject(Object attributeValue) fixes the value of the attributeValue |
| * in cases where it is null and indirection requires that it contain some specific data structure. Return whether this will happen. |
| * This method is used to help determine if indirection has been triggered |
| * @see validateAttributeOfInstantiatedObject(Object attributeValue) |
| */ |
| @Override |
| public boolean isAttributeValueFullyBuilt(Object attributeValue){ |
| return true; |
| } |
| |
| |
| /** |
| * INTERNAL: |
| * Iterate over the specified attribute value, |
| */ |
| @Override |
| public void iterateOnAttributeValue(DescriptorIterator iterator, Object attributeValue) { |
| super.iterateOnAttributeValue(iterator, ((IndirectContainer)attributeValue).getValueHolder()); |
| } |
| |
| /** |
| * INTERNAL: |
| * Return the null value of the appropriate attribute. That is, the |
| * field from the database is NULL, return what should be |
| * placed in the object's attribute as a result. |
| * In this case, return an empty ValueHolder. |
| */ |
| @Override |
| public Object nullValueFromRow() { |
| return buildContainer(new ValueHolder()); |
| } |
| |
| /** |
| * Reset the wrapper used to store the value. |
| */ |
| @Override |
| public void reset(Object target) { |
| getMapping().setAttributeValueInObject(target, buildContainer(new ValueHolder())); |
| } |
| |
| /** |
| * INTERNAL: |
| * Return whether the specified object is instantiated. |
| */ |
| @Override |
| public boolean objectIsInstantiated(Object object) { |
| return ((IndirectContainer)object).getValueHolder().isInstantiated(); |
| } |
| |
| /** |
| * INTERNAL: |
| * Return whether the specified object can be instantiated without database access. |
| */ |
| @Override |
| public boolean objectIsEasilyInstantiated(Object object) { |
| ValueHolderInterface valueHolder = ((IndirectContainer)object).getValueHolder(); |
| if (valueHolder instanceof DatabaseValueHolder) { |
| return ((DatabaseValueHolder)valueHolder).isEasilyInstantiated(); |
| } else { |
| return true; |
| } |
| } |
| |
| /** |
| * Sets the Container class which implements IndirectContainer |
| */ |
| public void setContainerClass(Class containerClass) { |
| this.containerClass = containerClass; |
| } |
| |
| /** |
| * Set the container classname for the MW |
| */ |
| public void setContainterClassName(String containerClassName) { |
| this.containerClassName = containerClassName; |
| } |
| |
| /** |
| * INTERNAL: |
| * Set the value of the appropriate attribute of target to attributeValue. |
| * In this case, place the value inside the target's ValueHolder. |
| */ |
| @Override |
| public void setRealAttributeValueInObject(Object target, Object attributeValue) { |
| IndirectContainer container = (IndirectContainer)this.getMapping().getAttributeValueFromObject(target); |
| container.getValueHolder().setValue(attributeValue); |
| this.getMapping().setAttributeValueInObject(target, container); |
| } |
| |
| /** |
| * INTERNAL: |
| * Return whether the type is appropriate for the indirection policy. |
| * In this case, the type must either be assignable from IndirectContainer or |
| * allow the conatinerClass to be assigned to it. |
| */ |
| @Override |
| protected boolean typeIsValid(Class attributeType) { |
| return ClassConstants.IndirectContainer_Class.isAssignableFrom(attributeType) || attributeType.isAssignableFrom(getContainerClass()); |
| } |
| |
| /** |
| * INTERNAL: |
| * Verify that the value of the attribute within an instantiated object |
| * is of the appropriate type for the indirection policy. |
| * In this case, the attribute must be non-null and it must be a |
| * ValueHolderInterface. |
| */ |
| @Override |
| public Object validateAttributeOfInstantiatedObject(Object attributeValue) { |
| if (!(getContainerClass().isInstance(attributeValue))) { |
| throw DescriptorException.valueHolderInstantiationMismatch(attributeValue, this.getMapping()); |
| } |
| return attributeValue; |
| } |
| |
| /** |
| * INTERNAL: |
| * Return the value to be stored in the object's attribute. |
| * This value is determined by the batchQuery. |
| * In this case, wrap the query in a ValueHolder for later invocation. |
| */ |
| @Override |
| public Object valueFromBatchQuery(ReadQuery batchQuery, AbstractRecord row, ObjectLevelReadQuery originalQuery, CacheKey parentCacheKey) { |
| ValueHolderInterface valueHolder = (ValueHolderInterface)super.valueFromBatchQuery(batchQuery, row, originalQuery, parentCacheKey); |
| return buildContainer(valueHolder); |
| } |
| |
| /** |
| * INTERNAL: |
| * Return the value to be stored in the object's attribute. |
| * This value is determined by invoking the appropriate |
| * method on the object and passing it the row and session. |
| * In this case, wrap the row in a ValueHolder for later use. |
| */ |
| @Override |
| public Object valueFromMethod(Object object, AbstractRecord row, AbstractSession session) { |
| ValueHolderInterface valueHolder = (ValueHolderInterface)super.valueFromMethod(object, row, session); |
| return buildContainer(valueHolder); |
| } |
| |
| /** |
| * INTERNAL: |
| * Return the value to be stored in the object's attribute. |
| * This value is determined by the query. |
| * In this case, wrap the query in a ValueHolder for later invocation. |
| */ |
| @Override |
| public Object valueFromQuery(ReadQuery query, AbstractRecord row, AbstractSession session) { |
| ValueHolderInterface valueHolder = (ValueHolderInterface)super.valueFromQuery(query, row, session); |
| return buildContainer(valueHolder); |
| } |
| |
| /** |
| * INTERNAL: |
| * Return the value to be stored in the object's attribute. |
| * This value is determined by the row. |
| * In this case, simply wrap the object in a ValueHolder. |
| */ |
| @Override |
| public Object valueFromRow(Object object) { |
| return buildContainer(new ValueHolder(object)); |
| } |
| } |
