org.eclipse.persistence.descriptors.copying.CloneCopyPolicy 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.descriptors.copying;
import java.lang.reflect.Method;
import org.eclipse.persistence.exceptions.DescriptorException;
import org.eclipse.persistence.internal.descriptors.ObjectBuilder;
import org.eclipse.persistence.internal.helper.Helper;
import org.eclipse.persistence.internal.security.PrivilegedAccessHelper;
import org.eclipse.persistence.internal.sessions.AbstractRecord;
import org.eclipse.persistence.queries.ObjectBuildingQuery;
import org.eclipse.persistence.sessions.DataRecord;
import org.eclipse.persistence.sessions.Session;
import org.eclipse.persistence.sessions.UnitOfWork;
/**
* Purpose: Allows a clone of an object to be created with a method that returns
* the cloned object.
*
* It is possible to define methods for two types of clones
*
* 1. methodName can be set to define the method EclipseLink uses to clone objects for it's
* own internal use. The objects created by this method will not be visible to the user, and
* instead used as a basis for comparison when a DeferredChangeDetectionPolicy used. This method will
* also be in place of the workingCopyMethod if it is not provided
*
* 2. workingCopyMethod this method is used to create the clone that is returned to the user when an
* Object is registered in a UnitOfWork
*/
public class CloneCopyPolicy extends AbstractCopyPolicy {
/** Allow for clone method to be specified. */
protected String methodName;
protected String workingCopyMethodName;
protected transient Method method;
protected transient Method workingCopyMethod;
public CloneCopyPolicy() {
super();
}
/**
* Clone through calling the clone method.
*/
@Override
public Object buildClone(Object domainObject, Session session) throws DescriptorException {
// Must allow for null clone method for 9.0.4 deployment XML.
if (this.getMethodName() == null) {
return getDescriptor().getObjectBuilder().buildNewInstance();
}
return PrivilegedAccessHelper.callDoPrivilegedWithException(
() -> PrivilegedAccessHelper.invokeMethod(this.getMethod(), domainObject, new Object[0]),
(ex) -> {
if (ex instanceof IllegalAccessException) {
return DescriptorException.illegalAccessWhileCloning(
domainObject, this.getMethodName(), this.getDescriptor(), ex);
}
return DescriptorException.targetInvocationWhileCloning(
domainObject, this.getMethodName(), this.getDescriptor(), ex);
}
);
}
/**
* Clone through the workingCopyClone method, or if not specified the clone method.
*/
@Override
public Object buildWorkingCopyClone(Object domainObject, Session session) throws DescriptorException {
if (this.getWorkingCopyMethodName() == null) {
//not implemented to perform special operations.
return this.buildClone(domainObject, session);
}
return PrivilegedAccessHelper.callDoPrivilegedWithException(
() -> PrivilegedAccessHelper.invokeMethod(this.getWorkingCopyMethod(), domainObject, new Object[0]),
(ex) -> {
if (ex instanceof IllegalAccessException) {
return DescriptorException.illegalAccessWhileCloning(domainObject, this.getMethodName(), this.getDescriptor(), ex);
}
return DescriptorException.targetInvocationWhileCloning(domainObject, this.getMethodName(), this.getDescriptor(), ex);
}
);
}
/**
* Create a new instance, unless a workingCopyClone method is specified, then build a new instance and clone it.
*/
@Override
public Object buildWorkingCopyCloneFromRow(DataRecord row, ObjectBuildingQuery query, Object primaryKey, UnitOfWork uow) throws DescriptorException {
// For now must preserve CMP code which builds heavy clones with a context.
// Also preserve for clients who use the copy policy.
ObjectBuilder builder = getDescriptor().getObjectBuilder();
if (getWorkingCopyMethodName() != null) {
Object original = builder.buildNewInstance();
builder.buildAttributesIntoShallowObject(original, (AbstractRecord)row, query);
return buildWorkingCopyClone(original, query.getSession());
} else {
return builder.buildNewInstance();
}
}
/**
* Return the clone method.
*/
protected Method getMethod() {
return method;
}
/**
* Return the clone method name.
*/
public String getMethodName() {
return methodName;
}
/**
* Return the workingCopyClone method.
* This is used to clone within a unit of work.
*/
protected Method getWorkingCopyMethod() {
return workingCopyMethod;
}
/**
* Return the workingCopyClone method name.
* This is used to clone within a unit of work.
*/
public String getWorkingCopyMethodName() {
return workingCopyMethodName;
}
/**
* Validate and build the methods.
*/
@Override
public void initialize(Session session) throws DescriptorException {
final Class javaClass = this.getDescriptor().getJavaClass();
try {
// Must allow for null clone method for 9.0.4 deployment XML.
if (this.getMethodName() != null) {
this.setMethod(Helper.getDeclaredMethod(javaClass, this.getMethodName(), new Class[0]));
}
} catch (NoSuchMethodException exception) {
session.getIntegrityChecker().handleError(DescriptorException.noSuchMethodWhileInitializingCopyPolicy(this.getMethodName(), this.getDescriptor(), exception));
} catch (SecurityException exception) {
session.getIntegrityChecker().handleError(DescriptorException.securityWhileInitializingCopyPolicy(this.getMethodName(), this.getDescriptor(), exception));
}
if (this.getWorkingCopyMethodName() != null) {
try {
this.setWorkingCopyMethod(Helper.getDeclaredMethod(javaClass, this.getWorkingCopyMethodName(), new Class[0]));
} catch (NoSuchMethodException exception) {
session.getIntegrityChecker().handleError(DescriptorException.noSuchMethodWhileInitializingCopyPolicy(this.getMethodName(), this.getDescriptor(), exception));
} catch (SecurityException exception) {
session.getIntegrityChecker().handleError(DescriptorException.securityWhileInitializingCopyPolicy(this.getMethodName(), this.getDescriptor(), exception));
}
}
}
/**
* Set the clone method.
*/
protected void setMethod(Method method) {
this.method = method;
}
/**
* Set the clone method name.
*/
public void setMethodName(String methodName) {
this.methodName = methodName;
}
/**
* Set the workingCopyClone method.
* This is used to clone within a unit of work.
*/
protected void setWorkingCopyMethod(Method method) {
this.workingCopyMethod = method;
}
/**
* Set the workingCopyClone method name.
* This is used to clone within a unit of work.
*/
public void setWorkingCopyMethodName(String methodName) {
this.workingCopyMethodName = methodName;
}
/**
* Return false as a shallow clone is returned, not a new instance.
*/
@Override
public boolean buildsNewInstance() {
return getMethodName() == null;
}
@Override
public String toString() {
return Helper.getShortClassName(this) + "(" + this.getMethodName() + ")";
}
}