oracle.toplink.essentials.queryframework.ObjectLevelReadQuery Maven / Gradle / Ivy
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package oracle.toplink.essentials.queryframework;
import java.util.*;
import oracle.toplink.essentials.exceptions.*;
import oracle.toplink.essentials.expressions.*;
import oracle.toplink.essentials.internal.expressions.*;
import oracle.toplink.essentials.internal.helper.*;
import oracle.toplink.essentials.internal.queryframework.*;
import oracle.toplink.essentials.mappings.*;
import oracle.toplink.essentials.querykeys.*;
import oracle.toplink.essentials.internal.sessions.AbstractRecord;
import oracle.toplink.essentials.internal.sessions.UnitOfWorkImpl;
import oracle.toplink.essentials.internal.sessions.AbstractSession;
import oracle.toplink.essentials.descriptors.ClassDescriptor;
/**
* Purpose:
* Abstract class for all read queries using objects.
*
*
Description:
* Contains common behavior for all read queries using objects.
*
* @author Yvon Lavoie
* @since TOPLink/Java 1.0
*/
public abstract class ObjectLevelReadQuery extends ObjectBuildingQuery {
/** Provide a default builder so that it's easier to be consistent */
protected ExpressionBuilder defaultBuilder;
/** Allows for the resulting objects to be refresh with the data from the database. */
protected boolean shouldRefreshIdentityMapResult;
/** Allow for the cache usage to be specified to enable in-memory querying. */
protected int cacheUsage;
// Note: UseDescriptorSetting will result in CheckCacheByPrimaryKey for most cases
// it simply allows the Descriptor's disable cache hits to be used
public static final int UseDescriptorSetting = -1;
public static final int DoNotCheckCache = 0;
public static final int CheckCacheByExactPrimaryKey = 1;
public static final int CheckCacheByPrimaryKey = 2;
public static final int CheckCacheThenDatabase = 3;
public static final int CheckCacheOnly = 4;
public static final int ConformResultsInUnitOfWork = 5;
/** INTERNAL: for bug 2612601 allow ability not to register results in UOW. */
protected boolean shouldRegisterResultsInUnitOfWork = true;
/** Allow for additional fields to be selected, used for m-m batch reading. */
protected Vector additionalFields;
/** Allow for a complex result to be return including the rows and objects, used for m-m batch reading. */
protected boolean shouldIncludeData;
/** CMP only. Allow users to configure whether finder should be executed in a uow or not. */
protected boolean shouldProcessResultsInUnitOfWork = true;
/** Indicates if distinct should be used or not. */
protected short distinctState;
public static final short UNCOMPUTED_DISTINCT = 0;
public static final short USE_DISTINCT = 1;
public static final short DONT_USE_DISTINCT = 2;
/**
* CR 3677
* Used to determine behaviour of indirection in InMemoryQuerying
* This should have been just a constant similar to distinct locking, etc. instead of an object that just has the state and no behavoir,
* the object instantiation adds un-needed overhead, but too late now.
*/
protected InMemoryQueryIndirectionPolicy inMemoryQueryIndirectionPolicy;
/**
* Used to set the read time on objects that use this query.
* Should be set to the time the query returned from the database.
*/
protected long executionTime = 0;
/**
* INTERNAL: This is the key for accessing unregistered and locked result in the query's properties.
* The uow and QueryBaseValueHolder use this property to record amd to retreive the result respectively.
*/
public static final String LOCK_RESULT_PROPERTY = "LOCK_RESULT";
/** Allow for a query level fetch group to be set. */
protected FetchGroup fetchGroup;
/** The pre-defined fetch group name. */
protected String fetchGroupName;
/** Flag to turn on/off the use of the default fetch group. */
protected boolean shouldUseDefaultFetchGroup = true;
/** PERF: Store if the query originally used the default lock mode. */
protected boolean wasDefaultLockMode = false;
/** Stores the non fetchjoin attributes, these are joins that will be
* represented in the where clause but not in the select */
protected Vector nonFetchJoinAttributeExpressions;
/** Stores the helper object for dealing with joined attributes */
protected JoinedAttributeManager joinedAttributeManager;
/**
* INTERNAL:
* Initialize the state of the query
*/
public ObjectLevelReadQuery() {
this.shouldRefreshIdentityMapResult = false;
this.distinctState = UNCOMPUTED_DISTINCT;
this.joinedAttributeManager = new JoinedAttributeManager(getDescriptor(), getExpressionBuilder(), this);
this.additionalFields = oracle.toplink.essentials.internal.helper.NonSynchronizedVector.newInstance(1);
this.cacheUsage = UseDescriptorSetting;
this.shouldIncludeData = false;
this.inMemoryQueryIndirectionPolicy = new InMemoryQueryIndirectionPolicy();
}
/**
* INTERNAL:
* Return if this query originally used the default lock mode.
*/
protected boolean wasDefaultLockMode() {
return wasDefaultLockMode;
}
/**
* INTERNAL:
* Set if this query originally used the default lock mode.
*/
protected void setWasDefaultLockMode(boolean wasDefaultLockMode) {
this.wasDefaultLockMode = wasDefaultLockMode;
}
/**
* INTERNAL:
* Clone the query
*/
public Object clone() {
ObjectLevelReadQuery cloneQuery = (ObjectLevelReadQuery)super.clone();
//CR#... must also clone the joined expressions as always joined attribute will be added
// don't use setters as this will trigger unprepare.
cloneQuery.joinedAttributeManager = (JoinedAttributeManager)cloneQuery.getJoinedAttributeManager().clone();
if (hasNonFetchJoinedAttributeExpressions()){
cloneQuery.setNonFetchJoinAttributeExpressions((Vector)this.nonFetchJoinAttributeExpressions.clone());
}
cloneQuery.joinedAttributeManager.setBaseQuery(cloneQuery);
return cloneQuery;
}
/**
* INTERNAL:
* Clone the query, including its selection criteria.
*
* Normally selection criteria are not cloned here as they are cloned
* later on during prepare.
*/
public Object deepClone() {
ObjectLevelReadQuery clone = (ObjectLevelReadQuery)clone();
if (getSelectionCriteria() != null) {
clone.setSelectionCriteria((Expression)getSelectionCriteria().clone());
} else if (defaultBuilder != null) {
clone.defaultBuilder = (ExpressionBuilder)defaultBuilder.clone();
}
return clone;
}
/**
* PUBLIC:
* Set the query to lock, this will also turn refreshCache on.
*/
public void acquireLocks() {
setLockMode(LOCK);
//Bug2804042 Must un-prepare if prepared as the SQL may change.
setIsPrepared(false);
}
/**
* PUBLIC:
* Set the query to lock without waiting (blocking), this will also turn refreshCache on.
*/
public void acquireLocksWithoutWaiting() {
setLockMode(LOCK_NOWAIT);
//Bug2804042 Must un-prepare if prepared as the SQL may change.
setIsPrepared(false);
}
/**
* INTERNAL:
* Additional fields can be added to a query. This is used in m-m bacth reading to bring back the key from the join table.
*/
public void addAdditionalField(DatabaseField field) {
getAdditionalFields().addElement(field);
//Bug2804042 Must un-prepare if prepared as the SQL may change.
setIsPrepared(false);
}
/**
* INTERNAL:
* Additional fields can be added to a query. This is used in m-m bacth reading to bring back the key from the join table.
*/
public void addAdditionalField(Expression fieldExpression) {
getAdditionalFields().addElement(fieldExpression);
//Bug2804042 Must un-prepare if prepared as the SQL may change.
setIsPrepared(false);
}
/**
* PUBLIC:
* Specify the one-to-one mapped attribute to be optimized in this query.
* The query will join the object(s) being read with the one-to-one attribute,
* this allows all of the data required for the object(s) to be read in a single query instead of (n) queries.
* This should be used when the application knows that it requires the part for all of the objects being read.
* This can be used only for one-to-one mappings where the target is not the same class as the source,
* either directly or through inheritance. Also two joins cannot be done to the same class.
*
*
Note: This cannot be used for objects where it is possible not to have a part,
* as these objects will be ommited from the result set,
* unless an outer join is used through passing and expression using "getAllowingNull".
*
*
Example: query.addJoinedAttribute("address")
*
* @see #addJoinedAttribute(Expression)
*/
public void addJoinedAttribute(String attributeName) {
addJoinedAttribute(getExpressionBuilder().get(attributeName));
}
/**
* PUBLIC:
* Specify the to-one or to-many mapped attribute to be optimized in this query.
* The query will join the object(s) being read with the specified attribute,
* this allows all of the data required for the object(s) to be read in a single query instead of (n) queries.
* This should be used when the application knows that it requires the part for all of the objects being read.
*
*
Note: This cannot be used for objects where it is possible not to have a part,
* as these objects will be ommited from the result set,
* unless an outer join is used through passing and expression using "getAllowingNull".
*
*
Example:
* The following will fetch along with Employee(s) "Jones" all projects they participate in
* along with teamLeaders and their addresses, teamMembers and their phones.
*
* query.setSelectionCriteria(query.getExpressionBuilder().get("lastName").equal("Jones"));
* Expression projects = query.getExpressionBuilder().anyOf("projects");
* query.addJoinedAttribute(projects);
* Expression teamLeader = projects.get("teamLeader");
* query.addJoinedAttribute(teamLeader);
* Expression teamLeaderAddress = teamLeader.getAllowingNull("address");
* query.addJoinedAttribute(teamLeaderAddress);
* Expression teamMembers = projects.anyOf("teamMembers");
* query.addJoinedAttribute(teamMembers);
* Expression teamMembersPhones = teamMembers.anyOfAllowingNone("phoneNumbers");
* query.addJoinedAttribute(teamMembersPhones);
*
* Note that:
* the order is essential: an expression should be added before any expression derived from it;
* the object is built once - it won't be rebuilt if it to be read again as a joined attribute:
* in the example the query won't get phones for "Jones" -
* even though they are among teamMembers (for whom phones are read).
*
*/
public void addJoinedAttribute(Expression attributeExpression) {
getJoinedAttributeManager().addJoinedAttributeExpression(attributeExpression);
//Bug2804042 Must un-prepare if prepared as the SQL may change.
// Joined attributes are now calculated in prePrepare.
setIsPrePrepared(false);
}
/**
* PUBLIC:
* Specify the one-to-one mapped attribute to be optimized in this query.
* The query will join the object(s) being read with the one-to-one
* attribute. The difference between this and a joined attribute is that
* it allows data to be retrieved based on a join, but will not populate
* the joined attribute. It also allows all of the data required for the
* object(s) to be read in a single query instead of (n) queries. This
* should be used when the application knows that it requires the part for
* all of the objects being read. This can be used only for one-to-one
* mappings where the target is not the same class as the source, either
* directly or through inheritance. Also two joins cannot be done to the
* same class.
*
*
Note: This cannot be used for objects where it is possible not to have
* a part, as these objects will be ommited from the result set, unless an
* outer join is used through passing and expression using "getAllowingNull".
*
*
Example: query.addNonFetchJoinedAttribute("address")
*
* @see #addNonFetchJoinedAttribute(Expression)
*/
public void addNonFetchJoinedAttribute(String attributeName) {
addNonFetchJoinedAttribute(getExpressionBuilder().get(attributeName));
}
/**
* PUBLIC:
* Specify the one-to-one mapped attribute to be optimized in this query.
* The query will join the object(s) being read with the one-to-one
* attribute. The difference between this and a joined attribute is that
* it allows data to be retrieved based on a join, but will not populate
* the joined attribute. It also allows all of the data required for the
* object(s) to be read in a single query instead of (n) queries. This
* should be used when the application knows that it requires the part for
* all of the objects being read. This can be used only for one-to-one
* mappings where the target is not the same class as the source, either
* directly or through inheritance. Also two joins cannot be done to the
* same class.
*
*
Note: This cannot be used for objects where it is possible not to have
* a part, as these objects will be ommited from the result set, unless an
* outer join is used through passing and expression using "getAllowingNull".
*
*
Example: query.addNonFetchJoinedAttribute(query.getExpressionBuilder().get("teamLeader").get("address"))
*
* @see #addNonFetchJoinedAttribute(Expression)
*/
public void addNonFetchJoinedAttribute(Expression attributeExpression) {
getNonFetchJoinAttributeExpressions().add(attributeExpression);
// Bug 2804042 Must un-prepare if prepared as the SQL may change.
// Joined attributes are now calculated in prePrepare.
setIsPrePrepared(false);
}
/**
* INTERNAL:
* Iterate through a list of joined expressions and add the fields they represent to a list
* of fields.
*/
protected void addSelectionFieldsForJoinedExpressions(List fields, List joinedExpressions) {
for (int index = 0; index < joinedExpressions.size(); index++) {
ObjectExpression objectExpression = (ObjectExpression)joinedExpressions.get(index);
// Expression may not have been initialized.
objectExpression.getBuilder().setSession(getSession().getRootSession(null));
objectExpression.getBuilder().setQueryClass(getReferenceClass());
ClassDescriptor descriptor = objectExpression.getMapping().getReferenceDescriptor();
fields.addAll(descriptor.getFields());
}
}
/**
* INTERNAL:
* Called by CursoredStream to construct objects from rows.
* Subclasses which build other results objects (ReportQuery, & PartialObjects) may override
*/
public Object buildObject(AbstractRecord row) {
return getDescriptor().getObjectBuilder().buildObject(this, row, this.getJoinedAttributeManager());
}
/**
* PUBLIC:
* The cache will checked completely, if the object is not found null will be returned or an error if the query is too complex.
* Queries can be configured to use the cache at several levels.
* Other caching option are available.
* @see #setCacheUsage(int)
*/
public void checkCacheOnly() {
setCacheUsage(CheckCacheOnly);
}
/**
* INTERNAL:
* Ensure that the descriptor has been set.
*/
public void checkDescriptor(AbstractSession session) throws QueryException {
if (getReferenceClass() == null) {
throw QueryException.referenceClassMissing(this);
}
if (getDescriptor() == null) {
ClassDescriptor referenceDescriptor = session.getDescriptor(getReferenceClass());
if (referenceDescriptor == null) {
throw QueryException.descriptorIsMissing(getReferenceClass(), this);
}
setDescriptor(referenceDescriptor);
}
}
/**
* INTERNAL:
* Contains the body of the check early return call, implemented by subclasses.
*/
protected abstract Object checkEarlyReturnImpl(AbstractSession session, AbstractRecord translationRow);
/**
* INTERNAL:
* Check to see if this query already knows the return vale without preforming any further work.
*/
public Object checkEarlyReturn(AbstractSession session, AbstractRecord translationRow) {
// For bug 3136413/2610803 building the selection criteria from an EJBQL string or
// an example object is done just in time.
// Also calls checkDescriptor here.
//buildSelectionCriteria(session);
checkPrePrepare(session);
if (!session.isUnitOfWork()) {
return checkEarlyReturnImpl(session, translationRow);
}
UnitOfWorkImpl unitOfWork = (UnitOfWorkImpl)session;
// The cache check must happen on the UnitOfWork in these cases either
// to access transient state or for pessimistic locking, as only the
// UOW knows which objects it has locked.
if (shouldCheckCacheOnly() || shouldConformResultsInUnitOfWork() || getDescriptor().shouldAlwaysConformResultsInUnitOfWork() || (getLockMode() != ObjectBuildingQuery.NO_LOCK)) {
Object result = checkEarlyReturnImpl(unitOfWork, translationRow);
if (result != null) {
return result;
}
}
// don't bother trying to get a cache hit on the parent session
// as if not in UnitOfWork it is not yet pessimistically locked
// on the database for sure.
// Note for ReadObjectQueries we totally ignore shouldCheckCacheOnly.
if (isReadObjectQuery() && isLockQuery()) {
return null;
}
// follow the execution path in looking for the object.
AbstractSession parentSession = unitOfWork.getParentIdentityMapSession(this);
// assert parentSession != unitOfWork;
Object result = checkEarlyReturn(parentSession, translationRow);
if (result != null) {
// Optimization: If find deleted object by exact primary key
// treat this as cache hit but return null. Bug 2782991.
if (result == InvalidObject.instance) {
return result;
}
return registerResultInUnitOfWork(result, unitOfWork, translationRow, false);
} else {
return null;
}
}
/**
* INTERNAL:
* Check to see if this query needs to be prepare and prepare it.
* The prepare is done on the original query to ensure that the work is not repeated.
*/
public void checkPrepare(AbstractSession session, AbstractRecord translationRow) {
// CR#3823735 For custom queries the prePrepare may not have been called yet.
checkPrePrepare(session);
super.checkPrepare(session, translationRow);
}
/**
* INTERNAL:
* ObjectLevelReadQueries now have an explicit pre-prepare stage, which
* is for checking for pessimistic locking, and computing any joined
* attributes declared on the descriptor.
*/
protected void checkPrePrepare(AbstractSession session) {
checkDescriptor(session);
// This query is first prepared for global common state, this must be synced.
if (!isPrePrepared()) {// Avoid the monitor is already prePrepare, must check again for concurrency.
synchronized (this) {
if (!isPrePrepared()) {
AbstractSession alreadySetSession = getSession();
setSession(session);// Session is required for some init stuff.
prePrepare();
setSession(alreadySetSession);
setIsPrePrepared(true);// MUST not set prepare until done as other thread may hit before finishing the prePrepare.
}
}
}
}
/**
* INTERNAL:
* The reference class has been changed, need to reset the
* descriptor. Null out the current descriptor and call
* checkDescriptor
* Added Feb 27, 2001 JED for EJBQL feature
*/
public void changeDescriptor(AbstractSession theSession) {
setDescriptor(null);
checkDescriptor(theSession);
}
/**
* INTERNAL:
* Conforms and registers an individual result. This instance could be one
* of the elements returned from a read all query, the result of a Read Object
* query, or an element read from a cursor.
*
* A result needs to be registered before it can be conformed, so
* registerIndividualResult is called here.
*
* Conforming on a result from the database is lenient. Since the object
* matched the query on the database we assume it matches here unless we can
* determine for sure that it was changed in this UnitOfWork not to conform.
* @param result may be an original, or a raw database row
* @param arguments the parameters this query was executed with
* @param selectionCriteriaClone the expression to conform to. If was a
* selection object or key, null (which all conform to) is used
* @param alreadyReturned a hashtable of objects already found by scanning
* the UnitOfWork cache for conforming instances. Prevents duplicates.
* @param buildDirectlyFromRows whether result is an original or a raw database
* row
* @return a clone, or null if result does not conform.
*/
protected Object conformIndividualResult(Object result, UnitOfWorkImpl unitOfWork, AbstractRecord arguments, Expression selectionCriteriaClone, IdentityHashtable alreadyReturned, boolean buildDirectlyFromRows) {
// First register the object. Since object is presently unwrapped the
// exact objects stored in the cache will be returned.
// The object is known to exist.
Object clone = registerIndividualResult(result, unitOfWork, buildDirectlyFromRows, null);
if (getDescriptor().hasWrapperPolicy() && getDescriptor().getWrapperPolicy().isWrapped(clone)) {
// The only time the clone could be wrapped is if we are not registering
// results in the unitOfWork and we are ready to return a final
// (unregistered) result now. Any further processing may accidently
// cause it to get registered.
return clone;
}
//bug 4459976 in order to maintain backward compatibility on ordering
// lets use the result as a guild for the final result not the hashtable
// of found objects.
if (unitOfWork.isObjectDeleted(clone) ) {
return null;
}
if (!isExpressionQuery() || (selectionCriteriaClone == null)) {
if (alreadyReturned != null) {
alreadyReturned.remove(clone);
}
return clone;
}
try {
// pass in the policy to assume that the object conforms if indirection is not triggered. This
// is valid because the query returned the object and we should trust the query that the object
// matches the selection criteria, and because the indirection is not triggered then the customer
//has not changed the value.
// bug 2637555
// unless for bug 3568141 use the painstaking shouldTriggerIndirection if set
InMemoryQueryIndirectionPolicy policy = getInMemoryQueryIndirectionPolicy();
if (!policy.shouldTriggerIndirection()) {
policy = new InMemoryQueryIndirectionPolicy(InMemoryQueryIndirectionPolicy.SHOULD_IGNORE_EXCEPTION_RETURN_CONFORMED);
}
if (selectionCriteriaClone.doesConform(clone, unitOfWork, arguments, policy)) {
if (alreadyReturned != null) {
alreadyReturned.remove(clone);
}
return clone;
}
} catch (QueryException exception) {
// bug 3570561: mask all-pervasive valueholder exceptions while conforming
if ((unitOfWork.getShouldThrowConformExceptions() == UnitOfWorkImpl.THROW_ALL_CONFORM_EXCEPTIONS) && (exception.getErrorCode() != QueryException.MUST_INSTANTIATE_VALUEHOLDERS)) {
throw exception;
}
if (alreadyReturned != null) {
alreadyReturned.remove(clone);
}
return clone;
}
return null;
}
/**
* PUBLIC:
* The cache will checked completely, if the object is not found the database will be queried,
* and the database result will be verified with what is in the cache and/or unit of work including new objects.
* This can lead to poor performance so it is recomended that only the database be queried in most cases.
* Queries can be configured to use the cache at several levels.
* Other caching option are available.
* @see #setCacheUsage(int)
*/
public void conformResultsInUnitOfWork() {
setCacheUsage(ConformResultsInUnitOfWork);
}
/**
* PUBLIC:
* Set the query not to lock.
*/
public void dontAcquireLocks() {
setLockMode(NO_LOCK);
//Bug2804042 Must un-prepare if prepared as the SQL may change.
setIsPrepared(false);
}
/**
* PUBLIC:
* This can be used to explicitly disable the cache hit.
* The cache hit may not be desired in some cases, such as
* stored procedures that accept the primary key but do not query on it.
*/
public void dontCheckCache() {
setCacheUsage(DoNotCheckCache);
}
/**
* PUBLIC:
* When unset means perform read normally and dont do refresh.
*/
public void dontRefreshIdentityMapResult() {
setShouldRefreshIdentityMapResult(false);
}
/**
* ADVANCED:
* If a distinct has been set the DISTINCT clause will be printed.
* This is used internally by TopLink for batch reading but may also be
* used directly for advanced queries or report queries.
*/
public void dontUseDistinct() {
setDistinctState(DONT_USE_DISTINCT);
//Bug2804042 Must un-prepare if prepared as the SQL may change.
setIsPrepared(false);
}
/**
* INTERNAL:
* There is a very special case where a query may be a bean-level
* pessimistic locking query.
*
* If that is so, only queries executed inside of a UnitOfWork should
* have a locking clause. In the extremely rare case that we execute
* a locking query outside of a UnitOfWork, must disable locking so that
* we do not get a fetch out of sequence error.
*/
public DatabaseQuery prepareOutsideUnitOfWork(AbstractSession session) {
// Implementation is complicated because: if locking refresh will be
// auto set to true preventing cache hit.
// Must prepare this query from scratch if outside uow but locking
// Must not reprepare this query as a NO_LOCK, but create a clone first
// Must not cloneAndUnPrepare unless really have to
if (isLockQuery(session) && getLockingClause().isForUpdateOfClause()) {
ObjectLevelReadQuery clone = (ObjectLevelReadQuery)clone();
clone.dontAcquireLocks();
clone.setIsPrepared(false);
clone.checkPrePrepare(session);
return clone;
}
return this;
}
/**
* INTERNAL:
* Execute the query. If there are objects in the cache return the results
* of the cache lookup.
*
* @param session - the session in which the receiver will be executed.
* @exception DatabaseException - an error has occurred on the database.
* @exception OptimisticLockException - an error has occurred using the optimistic lock feature.
* @return An object, the result of executing the query.
*/
public Object execute(AbstractSession session, AbstractRecord translationRow) throws DatabaseException, OptimisticLockException {
//Bug#2839852 Refreshing is not possible if the query uses checkCacheOnly.
if (shouldRefreshIdentityMapResult() && shouldCheckCacheOnly()) {
throw QueryException.refreshNotPossibleWithCheckCacheOnly(this);
}
return super.execute(session, translationRow);
}
/*
* Executes the prepared query on the datastore.
*/
public Object executeDatabaseQuery() throws DatabaseException {
if (getSession().isUnitOfWork()) {
UnitOfWorkImpl unitOfWork = (UnitOfWorkImpl)getSession();
// Note if a nested unit of work this will recursively start a
// transaction early on the parent also.
if (isLockQuery()) {
if ((!unitOfWork.getCommitManager().isActive()) && (!unitOfWork.wasTransactionBegunPrematurely())) {
unitOfWork.beginTransaction();
unitOfWork.setWasTransactionBegunPrematurely(true);
}
}
if (unitOfWork.isNestedUnitOfWork()) {
UnitOfWorkImpl nestedUnitOfWork = (UnitOfWorkImpl)getSession();
setSession(nestedUnitOfWork.getParent());
Object result = executeDatabaseQuery();
setSession(nestedUnitOfWork);
return registerResultInUnitOfWork(result, nestedUnitOfWork, getTranslationRow(), false);
}
}
session.validateQuery(this);// this will update the query with any settings
if (getQueryId() == 0) {
setQueryId(getSession().getNextQueryId());
}
return executeObjectLevelReadQuery();
}
/*
* Executes the prepared query on the datastore.
*/
protected abstract Object executeObjectLevelReadQuery() throws DatabaseException;
/**
* INTERNAL:
* At this point only the code has been copied over from UnitOfWork
* internalExecuteQuery. No work has been done.
* @param unitOfWork
* @param translationRow
* @return
* @throws oracle.toplink.essentials.exceptions.DatabaseException
* @throws oracle.toplink.essentials.exceptions.OptimisticLockException
*/
public Object executeInUnitOfWork(UnitOfWorkImpl unitOfWork, AbstractRecord translationRow) throws DatabaseException, OptimisticLockException {
if (!shouldMaintainCache()) {
return unitOfWork.getParent().executeQuery(this, translationRow);
}
Object result = execute(unitOfWork, translationRow);
// Optimization: If find deleted object on uow by exact primary key
// treat this as cache hit but return null. Bug 2782991.
if (result == InvalidObject.instance) {
return null;
}
return result;
}
/**
* INTERNAL:
* Additional fields can be added to a query. This is used in m-m bacth reading to bring back the key from the join table.
*/
public Vector getAdditionalFields() {
return additionalFields;
}
/**
* PUBLIC:
* Return the cache usage.
* By default only primary key read object queries will first check the cache before accessing the database.
* Any query can be configure to query against the cache completely, by key or ignore the cache check.
*
Valid values are:
*
* - DoNotCheckCache
*
- CheckCacheByExactPrimaryKey
*
- CheckCacheByPrimaryKey
*
- CheckCacheThenDatabase
*
- CheckCacheOnly
*
- ConformResultsInUnitOfWork
*
- UseDescriptorSetting
* Note: UseDescriptorSetting functions like CheckCacheByPrimaryKey, except checks the appropriate descriptor's
* shouldDisableCacheHits setting when querying on the cache.
*
*/
public int getCacheUsage() {
return cacheUsage;
}
/**
* ADVANCED:
* If a distinct has been set the DISTINCT clause will be printed.
* This is used internally by TopLink for batch reading but may also be
* used directly for advanced queries or report queries.
*/
public short getDistinctState() {
return distinctState;
}
/**
* REQUIRED:
* Get the expression builder which should be used for this query.
* This expression builder should be used to build all expressions used by this query.
*/
public ExpressionBuilder getExpressionBuilder() {
if (defaultBuilder == null) {
initializeDefaultBuilder();
}
return defaultBuilder;
}
/**
* INTERNAL
* Sets the default expression builder for this query.
*/
public void setExpressionBuilder(ExpressionBuilder builder) {
this.defaultBuilder = builder;
}
/**
* PUBLIC:
* Returns the InMemoryQueryIndirectionPolicy for this query
*/
public InMemoryQueryIndirectionPolicy getInMemoryQueryIndirectionPolicy() {
return this.inMemoryQueryIndirectionPolicy;
}
/**
* INTERNAL:
* Set the list of expressions that represent elements that are joined because of their
* mapping for this query.
*/
public JoinedAttributeManager getJoinedAttributeManager() {
return this.joinedAttributeManager;
}
/**
* INTERNAL:
* Return the attributes that must be joined, but not fetched, that is,
* do not trigger the value holder.
*/
public Vector getNonFetchJoinAttributeExpressions() {
if (this.nonFetchJoinAttributeExpressions == null){
this.nonFetchJoinAttributeExpressions = oracle.toplink.essentials.internal.helper.NonSynchronizedVector.newInstance();
}
return nonFetchJoinAttributeExpressions;
}
/**
* INTERNAL:
* Lookup the mapping for this item by traversing its expression recursively.
* If an aggregate of foreign mapping is found it is traversed.
*/
public DatabaseMapping getLeafMappingFor(Expression expression, ClassDescriptor rootDescriptor) throws QueryException {
// Check for database field expressions or place holder
if ((expression == null) || (expression.isFieldExpression())) {
return null;
}
if (!(expression.isQueryKeyExpression())) {
return null;
}
QueryKeyExpression qkExpression = (QueryKeyExpression)expression;
Expression baseExpression = qkExpression.getBaseExpression();
ClassDescriptor descriptor = getLeafDescriptorFor(baseExpression, rootDescriptor);
return descriptor.getMappingForAttributeName(qkExpression.getName());
}
/**
* INTERNAL:
* Lookup the descriptor for this item by traversing its expression recursively.
* @param expression
* @param rootDescriptor
* @return
* @throws oracle.toplink.essentials.exceptions.QueryException
*/
public ClassDescriptor getLeafDescriptorFor(Expression expression, ClassDescriptor rootDescriptor) throws QueryException {
// The base case
if (expression.isExpressionBuilder()) {
// The following special case is where there is a parallel builder
// which has a different reference class as the primary builder.
Class queryClass = ((ExpressionBuilder)expression).getQueryClass();
if ((queryClass != null) && (queryClass != getReferenceClass())) {
return getSession().getDescriptor(queryClass);
}
return rootDescriptor;
}
Expression baseExpression = ((QueryKeyExpression)expression).getBaseExpression();
ClassDescriptor baseDescriptor = getLeafDescriptorFor(baseExpression, rootDescriptor);
ClassDescriptor descriptor = null;
String attributeName = expression.getName();
DatabaseMapping mapping = baseDescriptor.getMappingForAttributeName(attributeName);
if (mapping == null) {
QueryKey queryKey = baseDescriptor.getQueryKeyNamed(attributeName);
if (queryKey != null) {
if (queryKey.isForeignReferenceQueryKey()) {
descriptor = getSession().getDescriptor(((ForeignReferenceQueryKey)queryKey).getReferenceClass());
} else// if (queryKey.isDirectQueryKey())
{
descriptor = queryKey.getDescriptor();
}
}
if (descriptor == null) {
throw QueryException.invalidExpressionForQueryItem(expression, this);
}
} else if (mapping.isAggregateObjectMapping()) {
descriptor = ((AggregateObjectMapping)mapping).getReferenceDescriptor();
} else if (mapping.isForeignReferenceMapping()) {
descriptor = ((ForeignReferenceMapping)mapping).getReferenceDescriptor();
}
return descriptor;
}
/**
* PUBLIC:
* Return the current locking mode.
*/
public short getLockMode() {
if (lockingClause == null) {
return DEFAULT_LOCK_MODE;
} else {
return lockingClause.getLockMode();
}
}
/**
* INTERNAL:
* It is not exactly as simple as a query being either locking or not.
* Any combination of the reference class object and joined attributes
* may be locked.
*/
public ForUpdateClause getLockingClause() {
return lockingClause;
}
/**
* INTERNAL:
* Return the time this query actually went to the database
*/
public long getExecutionTime() {
return executionTime;
}
/**
* PUBLIC:
* Return the reference class of the query.
*/
// TODO This method is left in so the javadoc remains, but is actually implemented on
// super. We should reconsider this.
public Class getReferenceClass() {
return super.getReferenceClass();
}
/**
* INTERNAL:
* Return the reference class of the query.
*/
// TODO This method is left in so the javadoc remains, but is actually implemented on
// super. We should reconsider this.
public String getReferenceClassName() {
return super.getReferenceClassName();
}
/**
* PUBLIC:
* Answers if the domain objects are to be read as of a past time.
* @see #getAsOfClause()
*/
public boolean hasAsOfClause() {
return ((defaultBuilder != null) && defaultBuilder.hasAsOfClause());
}
/**
* INTERNAL:
* Return the attributes that must be joined.
*/
public boolean hasNonFetchJoinedAttributeExpressions() {
return this.nonFetchJoinAttributeExpressions != null && !this.nonFetchJoinAttributeExpressions.isEmpty();
}
/**
* INTERNAL:
* Return if partial attributes.
*/
public boolean hasPartialAttributeExpressions() {
return false;
}
/**
* INTERNAL:
* Return the fields selected by the query.
* This includes the partial or joined fields.
* This is used for custom SQL executions.
*/
public Vector getSelectionFields() {
if ((!hasPartialAttributeExpressions()) && (!getJoinedAttributeManager().hasJoinedAttributes()) && (!hasFetchGroupAttributeExpressions())) {
return getDescriptor().getAllFields();
}
Vector fields;
if (hasFetchGroupAttributeExpressions()) {//fetch group support
List fetchGroupAttrExps = getFetchGroup().getFetchGroupAttributeExpressions();
fields = new Vector(fetchGroupAttrExps.size());
for (int index = 0; index < fetchGroupAttrExps.size(); index++) {
Expression expression = (Expression)fetchGroupAttrExps.get(index);
// Expression may not have been initialized.
expression.getBuilder().setSession(getSession().getRootSession(null));
expression.getBuilder().setQueryClass(getReferenceClass());
Helper.addAllToVector(fields, expression.getFields());
}
} else {
fields = new Vector(getDescriptor().getAllFields().size() + getJoinedAttributeManager().getJoinedAttributeExpressions().size() + getJoinedAttributeManager().getJoinedMappingExpressions().size());
Helper.addAllToVector(fields, getDescriptor().getAllFields());
addSelectionFieldsForJoinedExpressions(fields, getJoinedAttributeManager().getJoinedAttributeExpressions());
addSelectionFieldsForJoinedExpressions(fields, getJoinedAttributeManager().getJoinedMappingExpressions());
}
return fields;
}
/**
* Initialize the expression builder which should be used for this query. If
* there is a where clause, use its expression builder, otherwise
* generate one and cache it. This helps avoid unnecessary rebuilds.
*/
protected void initializeDefaultBuilder() {
DatabaseQueryMechanism mech = getQueryMechanism();
if (mech.isExpressionQueryMechanism() && ((ExpressionQueryMechanism)mech).getExpressionBuilder() != null) {
this.defaultBuilder = ((ExpressionQueryMechanism)mech).getExpressionBuilder();
return;
}
this.defaultBuilder = new ExpressionBuilder();
}
/**
* INTERNAL:
* return true if this query has computed its distinct value already
*/
public boolean isDistinctComputed() {
return getDistinctState() != UNCOMPUTED_DISTINCT;
}
/**
* PUBLIC:
* Answers if the query lock mode is known to be LOCK or LOCK_NOWAIT.
*
* In the case of DEFAULT_LOCK_MODE and the query reference class being a CMP entity bean,
* at execution time LOCK, LOCK_NOWAIT, or NO_LOCK will be decided.
*
* If a single joined attribute was configured for pessimistic locking then
* this will return true (after first execution) as the SQL contained a
* FOR UPDATE OF clause.
*/
public boolean isLockQuery() {
return getLockMode() > NO_LOCK;
}
/**
* ADVANCED:
* Answers if this query will issue any pessimistic locks.
*
* If the lock mode is not known (DEFAULT_LOCK_MODE / descriptor specified
* fine-grained locking) the lock mode will be determined now, to be either
* LOCK, LOCK_NOWAIT, or NO_LOCK.
* @see #isLockQuery()
*/
public boolean isLockQuery(oracle.toplink.essentials.sessions.Session session) {
checkPrePrepare((AbstractSession)session);
return isLockQuery();
}
/**
* PUBLIC:
* Return if this is an object level read query.
*/
public boolean isObjectLevelReadQuery() {
return true;
}
/**
* PUBLIC:
* Queries prepare common stated in themselves.
*/
protected boolean isPrePrepared() {
return isPrePrepared;
}
/**
* INTERNAL:
* Answers if we are executing through a UnitOfWork and registering results.
* This is only ever false if using the conforming without registering
* feature.
*/
protected boolean isRegisteringResults() {
return ((shouldRegisterResultsInUnitOfWork() && getDescriptor().shouldRegisterResultsInUnitOfWork()) || isLockQuery());
}
/**
* INTERNAL:
* If changes are made to the query that affect the derived SQL or Call
* parameters the query needs to be prepared again.
*
* Automatically called internally.
*
* The early phase of preparation is to check if this is a pessimistic
* locking query.
*/
protected void setIsPrePrepared(boolean isPrePrepared) {
// Only unprepare if was prepared to begin with, prevent unpreparing during prepare.
if (this.isPrePrepared && !isPrePrepared) {
setIsPrepared(false);
this.getJoinedAttributeManager().reset();
}
this.isPrePrepared = isPrePrepared;
}
/**
* INTERNAL:
* Prepare the receiver for execution in a session.
*/
protected void prepare() throws QueryException {
super.prepare();
prepareQuery();
}
/**
* INTERNAL:
* Prepare the receiver for execution in a session.
*/
protected void prePrepare() throws QueryException {
// For bug 3136413/2610803 building the selection criteria from an EJBQL string or
// an example object is done just in time.
buildSelectionCriteria(session);
checkDescriptor(session);
// Add mapping joined attributes.
if (getQueryMechanism().isExpressionQueryMechanism()) {
getJoinedAttributeManager().processJoinedMappings();
}
// modify query for locking only if locking has not been configured
if (isDefaultLock()) {
setWasDefaultLockMode(true);
ForUpdateOfClause lockingClause = null;
if (getJoinedAttributeManager().hasJoinedExpressions()) {
lockingClause = getJoinedAttributeManager().setupLockingClauseForJoinedExpressions(lockingClause, getSession());
}
if (lockingClause == null) {
this.lockingClause = ForUpdateClause.newInstance(NO_LOCK);
} else {
this.lockingClause = lockingClause;
// SPECJ: Locking not compatible with distinct for batch reading.
dontUseDistinct();
}
} else if (getLockMode() == NO_LOCK) {
setWasDefaultLockMode(true);
}
}
/**
* INTERNAL:
* Prepare the receiver for execution in a session.
*/
protected void prepareQuery() throws QueryException {
if ((!shouldMaintainCache()) && shouldRefreshIdentityMapResult() && (!descriptor.isAggregateCollectionDescriptor())) {
throw QueryException.refreshNotPossibleWithoutCache(this);
}
if (shouldMaintainCache() && hasPartialAttributeExpressions()) {
throw QueryException.cannotCachePartialObjects(this);
}
if (descriptor.isAggregateDescriptor()) {
// Not allowed
throw QueryException.aggregateObjectCannotBeDeletedOrWritten(descriptor, this);
}
// If fetch group manager is not set in the descriptor and the user attempts to use fetch group in the query dynamiclly, throw exception here.
if ((!getDescriptor().hasFetchGroupManager()) && ((getFetchGroup() != null) || (getFetchGroupName() != null))) {
throw QueryException.fetchGroupValidOnlyIfFetchGroupManagerInDescriptor(getDescriptor().getJavaClassName(), getName());
}
// Prepare fetch group if applied.
if (getDescriptor().hasFetchGroupManager()) {
getDescriptor().getFetchGroupManager().prepareQueryWithFetchGroup(this);
}
// Validate and prepare join expressions.
if (getJoinedAttributeManager().hasJoinedExpressions()) {
getJoinedAttributeManager().prepareJoinExpressions(getSession());
} else {
// If the query is being re-prepared must clear possible old cached data.
getJoinedAttributeManager().reset();
}
}
/**
* PUBLIC:
* Refresh the attributes of the object(s) resulting from the query.
* If cascading is used the private parts of the objects will also be refreshed.
*/
public void refreshIdentityMapResult() {
setShouldRefreshIdentityMapResult(true);
}
/**
* INTERNAL:
* All objects queried via a UnitOfWork get registered here. If the query
* went to the database.
*
* Involves registering the query result individually and in totality, and
* hence refreshing / conforming is done here.
*
* @param result may be collection (read all) or an object (read one),
* or even a cursor. If in transaction the shared cache will
* be bypassed, meaning the result may not be originals from the parent
* but raw database rows.
* @param unitOfWork the unitOfWork the result is being registered in.
* @param arguments the original arguments/parameters passed to the query
* execution. Used by conforming
* @param buildDirectlyFromRows If in transaction must construct
* a registered result from raw database rows.
*
* @return the final (conformed, refreshed, wrapped) UnitOfWork query result
*/
public abstract Object registerResultInUnitOfWork(Object result, UnitOfWorkImpl unitOfWork, AbstractRecord arguments, boolean buildDirectlyFromRows);
/**
* ADVANCED:
* If a distinct has been set the DISTINCT clause will be printed.
* This is used internally by TopLink for batch reading but may also be
* used directly for advanced queries or report queries.
*/
public void resetDistinct() {
setDistinctState(UNCOMPUTED_DISTINCT);
//Bug2804042 Must un-prepare if prepared as the SQL may change.
setIsPrepared(false);
}
/**
* INTERNAL:
* Additional fields can be added to a query. This is used in m-m bacth reading to bring back the key from the join table.
*/
public void setAdditionalFields(Vector additionalFields) {
this.additionalFields = additionalFields;
}
/**
* PUBLIC:
* Set the cache usage.
* By default only primary key read object queries will first check the cache before accessing the database.
* Any query can be configure to query against the cache completely, by key or ignore the cache check.
*
Valid values are:
*
* - DoNotCheckCache - The query does not check the cache but accesses the database, the cache will still be maintain.
*
- CheckCacheByExactPrimaryKey - If the query is exactly and only on the object's primary key the cache will be checked.
*
- CheckCacheByPrimaryKey - If the query contains the primary key and possible other values the cache will be checked.
*
- CheckCacheThenDatabase - The whole cache will be checked to see if there is any object matching the query, if not the database will be accessed.
*
- CheckCacheOnly - The whole cache will be checked to see if there is any object matching the query, if not null or an empty collection is returned.
*
- ConformResultsAgainstUnitOfWork - The results will be checked againtst the changes within the unit of work and object no longer matching or deleted will be remove, matching new objects will also be added.
*
- shouldCheckDescriptorForCacheUsage - This setting functions like CheckCacheByPrimaryKey, except checks the appropriate descriptor's
* shouldDisableCacheHits setting when querying on the cache.
*
*/
public void setCacheUsage(int cacheUsage) {
this.cacheUsage = cacheUsage;
}
/**
* INTERNAL:
* Set the descriptor for the query.
*/
public void setDescriptor(ClassDescriptor descriptor) {
super.setDescriptor(descriptor);
if (this.joinedAttributeManager != null){
this.joinedAttributeManager.setDescriptor(descriptor);
}
}
/**
* ADVANCED:
* If a distinct has been set the DISTINCT clause will be printed.
* This is used internally by TopLink for batch reading but may also be
* used directly for advanced queries or report queries.
*/
public void setDistinctState(short distinctState) {
this.distinctState = distinctState;
}
/**
* INTERNAL:
* Set the the time this query went to the database.
*/
public void setExecutionTime(long executionTime) {
this.executionTime = executionTime;
}
/**
* PUBLIC:
* Set the InMemoryQueryIndirectionPolicy for this query
*/
//Feature 2297
public void setInMemoryQueryIndirectionPolicy(InMemoryQueryIndirectionPolicy inMemoryQueryIndirectionPolicy) {
//Bug2862302 Backwards compatibility. This makes sure 9.0.3 and any older version project xml don't break
if (inMemoryQueryIndirectionPolicy != null) {
this.inMemoryQueryIndirectionPolicy = inMemoryQueryIndirectionPolicy;
}
}
/**
* PUBLIC:
* Sets whether this is a pessimistically locking query.
*
* - ObjectBuildingQuery.LOCK: SELECT .... FOR UPDATE issued.
*
- ObjectBuildingQuery.LOCK_NOWAIT: SELECT .... FOR UPDATE NO WAIT issued.
*
- ObjectBuildingQuery.NO_LOCK: no pessimistic locking.
*
- ObjectBuildingQuery.DEFAULT_LOCK_MODE (default) and you have a CMP descriptor:
* fine grained locking will occur.
*
* Fine Grained Locking: On execution the reference class
* and those of all joined attributes will be checked. If any of these have a
* PessimisticLockingPolicy set on their descriptor, they will be locked in a
* SELECT ... FOR UPDATE OF ... {NO WAIT}. Issues fewer locks
* and avoids setting the lock mode on each query.
*
Example:readAllQuery.setSelectionCriteria(employee.get("address").equal("Ottawa"));
*
- LOCK: all employees in Ottawa and all referenced Ottawa addresses will be locked.
*
- DEFAULT_LOCK_MODE: if address is a joined attribute, and only address has a pessimistic
* locking policy, only referenced Ottawa addresses will be locked.
*
* @see oracle.toplink.essentials.descriptors.PessimisticLockingPolicy
*/
public void setLockMode(short lockMode) {
if ((lockMode == LOCK) || (lockMode == LOCK_NOWAIT)) {
lockingClause = ForUpdateClause.newInstance(lockMode);
setShouldRefreshIdentityMapResult(true);
} else if (lockMode == NO_LOCK) {
lockingClause = ForUpdateClause.newInstance(lockMode);
} else {
lockingClause = null;
setIsPrePrepared(false);
}
setIsPrepared(false);
}
/**
* INTERNAL:
* Return the attributes that must be joined, but not fetched, that is,
* do not trigger the value holder.
*/
protected void setNonFetchJoinAttributeExpressions(Vector nonFetchJoinExpressions) {
this.nonFetchJoinAttributeExpressions = nonFetchJoinExpressions;
}
/**
* INTERNAL:
* The locking clause contains a list of expressions representing which
* objects are to be locked by the query.
*
* Use for even finer grained control over what is and is not locked by
* a particular query.
*/
public void setLockingClause(ForUpdateClause clause) {
if (clause.isForUpdateOfClause()) {
this.lockingClause = clause;
setIsPrePrepared(false);
} else {
setLockMode(clause.getLockMode());
}
}
public void setEJBQLString(String ejbqlString) {
super.setEJBQLString(ejbqlString);
setIsPrePrepared(false);
}
/**
* REQUIRED:
* Set the reference class for the query.
*/
// TODO This method is left in so the javadoc remains, but is actually implemented on
// super. We should reconsider this.
public void setReferenceClass(Class aClass) {
super.setReferenceClass(aClass);
}
/**
* INTERNAL:
* Set the reference class for the query.
*/
// TODO This method is left in so the javadoc remains, but is actually implemented on
// super. We should reconsider this.
public void setReferenceClassName(String aClass) {
super.setReferenceClassName(aClass);
}
public void setSelectionCriteria(Expression expression) {
super.setSelectionCriteria(expression);
if ((expression != null) && (defaultBuilder != null)) {
// For flashback: Must make sure expression and defaultBuilder always in sync.
ExpressionBuilder newBuilder = expression.getBuilder();
if ( (newBuilder != defaultBuilder) && (newBuilder.getQueryClass() == null || newBuilder.getQueryClass().equals(defaultBuilder.getQueryClass()) )){
defaultBuilder = newBuilder;
}
}
}
/**
* INTERNAL:
* Set if the rows for the result of the query should also be returned using a complex query result.
* @see ComplexQueryResult
*/
public void setShouldIncludeData(boolean shouldIncludeData) {
this.shouldIncludeData = shouldIncludeData;
}
/**
* PUBLIC:
* Set if the attributes of the object(s) resulting from the query should be refreshed.
* If cascading is used the private parts of the objects will also be refreshed.
*/
public void setShouldRefreshIdentityMapResult(boolean shouldRefreshIdentityMapResult) {
this.shouldRefreshIdentityMapResult = shouldRefreshIdentityMapResult;
}
/**
* INTERNAL:
* Set to false to have queries conform to a UnitOfWork without registering
* any additional objects not already in that UnitOfWork.
* @see #shouldRegisterResultsInUnitOfWork
* @bug 2612601
*/
public void setShouldRegisterResultsInUnitOfWork(boolean shouldRegisterResultsInUnitOfWork) {
this.shouldRegisterResultsInUnitOfWork = shouldRegisterResultsInUnitOfWork;
}
/**
* PUBLIC:
* Return if cache should be checked.
*/
public boolean shouldCheckCacheOnly() {
return getCacheUsage() == CheckCacheOnly;
}
/**
* PUBLIC:
* Return whether the descriptor's disableCacheHits setting should be checked prior
* to querying the cache.
*/
public boolean shouldCheckDescriptorForCacheUsage() {
return getCacheUsage() == UseDescriptorSetting;
}
/**
* PUBLIC:
* Should the results will be checked against the changes within the unit of work and object no longer matching or deleted will be remove, matching new objects will also be added..
*/
public boolean shouldConformResultsInUnitOfWork() {
return getCacheUsage() == ConformResultsInUnitOfWork;
}
/**
* INTERNAL:
* return true if this query should use a distinct
*/
public boolean shouldDistinctBeUsed() {
return getDistinctState() == USE_DISTINCT;
}
/**
* INTERNAL:
* Return if the rows for the result of the query should also be returned using a complex query result.
* @see ComplexQueryResult
*/
public boolean shouldIncludeData() {
return shouldIncludeData;
}
/**
* INTERNAL:
* Allows one to do conforming in a UnitOfWork without registering.
* Queries executed on a UnitOfWork will only return working copies for objects
* that have already been registered.
*
Extreme care should be taken in using this feature, for a user will
* get back a mix of registered and original (unregistered) objects.
*
Best used with a WrapperPolicy where invoking on an object will trigger
* its registration (CMP). Without a WrapperPolicy {@link oracle.toplink.essentials.sessions.UnitOfWork#registerExistingObject registerExistingObject}
* should be called on any object that you intend to change.
* @return true by default.
* @see #setShouldRegisterResultsInUnitOfWork(boolean)
* @see oracle.toplink.essentials.publicinterface.Descriptor#shouldRegisterResultsInUnitOfWork()
* @bug 2612601
*/
public boolean shouldRegisterResultsInUnitOfWork() {
return shouldRegisterResultsInUnitOfWork;
}
/**
* INTERNAL:
* Return if this is a full object query, not partial nor fetch group.
*/
public boolean shouldReadAllMappings() {
return (!hasPartialAttributeExpressions()) && (!hasFetchGroupAttributeExpressions());
}
/**
* INTERNAL:
* Check if the mapping is part of the partial attributes.
*/
public boolean shouldReadMapping(DatabaseMapping mapping) {
if ((!hasPartialAttributeExpressions()) && (!hasFetchGroupAttributeExpressions())) {
return true;
}
// bug 3659145
if (hasFetchGroupAttributeExpressions()) {
return isFetchGroupAttribute(mapping.getAttributeName());
}
return true;
}
/**
* PUBLIC:
* Set to a boolean. When set means refresh the instance
* variables of referenceObject from the database.
*/
public boolean shouldRefreshIdentityMapResult() {
return shouldRefreshIdentityMapResult;
}
public String toString() {
if (getReferenceClass() == null) {
return super.toString();
}
return Helper.getShortClassName(getClass()) + "(" + getReferenceClass().getName() + ")";
}
/**
* ADVANCED:
* Used for CMP only. This allows users to indicate whether cmp finders executed
* at the beginning of a transaction should always be run against a UnitOfWork.
* Defaults to true.
*
* If set to false, then UnitOfWork allocation will be deferred until a business
* method (including creates/removes) or finder with shouldProcessResultsInUnitOfWork == true
* is invoked. Any finder executed before such a time, will do so against the
* underlying ServerSession. Forcing finder execution to always go through a
* UnitOfWork means the results will be cloned and cached in the UnitOfWork up
* front. This is desired when the results will be accessed in the same transaction.
*
* Note that finders executed with an unspecified transaction context will never
* be executed against a UnitOfWork, even if this setting is true. This case may happen
* with the NotSupported, Never, and Supports attributes.
*/
public void setShouldProcessResultsInUnitOfWork(boolean processResultsInUnitOfWork) {
this.shouldProcessResultsInUnitOfWork = processResultsInUnitOfWork;
}
/**
* ADVANCED:
* Used for CMP only. Indicates whether cmp finders executed at the beginning
* of a transaction should always be run against a UnitOfWork.
* Defaults to true.
*
* If set to false, then UnitOfWork allocation will be deferred until a business
* method (including creates/removes) or finder with shouldProcessResultsInUnitOfWork == true
* is invoked. Any finder executed before such a time, will do so against the
* underlying ServerSession. Forcing finder execution to always go through a
* UnitOfWork means the results will be cloned and cached in the UnitOfWork up
* front. This is desired when the results will be accessed in the same transaction.
*
* Note that finders executed with an unspecified transaction context will never
* be executed against a UnitOfWork, even if this setting is true. This case may happen
* with the NotSupported, Never, and Supports attributes.
*/
public boolean shouldProcessResultsInUnitOfWork() {
return this.shouldProcessResultsInUnitOfWork;
}
/**
* ADVANCED:
* If a distinct has been set the DISTINCT clause will be printed.
* This is used internally by TopLink for batch reading but may also be
* used directly for advanced queries or report queries.
*/
public void useDistinct() {
setDistinctState(USE_DISTINCT);
//Bug2804042 Must un-prepare if prepared as the SQL may change.
setIsPrepared(false);
}
/**
* INTERNAL:
* Helper method that checks if clone has been locked with uow.
*/
public boolean isClonePessimisticLocked(Object clone, UnitOfWorkImpl uow) {
return false;
}
/**
* INTERNAL:
* Helper method that records clone with uow if query is pessimistic locking.
*/
public void recordCloneForPessimisticLocking(Object clone, UnitOfWorkImpl uow) {
if ((isLockQuery()) && lockingClause.isReferenceClassLocked()) {
uow.addPessimisticLockedClone(clone);
}
}
/**
* INTERNAL: Helper method to determine the default mode. If true and quey has a pessimistic locking policy,
* locking will be configured according to the pessimistic locking policy.
*/
public boolean isDefaultLock() {
return (lockingClause == null);
}
/**
* Return the fetch group set in the query.
* If a fetch group is not explicitly set in the query, default fetch group optionally defined in the decsiptor
* would be used, unless the user explicitly calls query.setShouldUseDefaultFetchGroup(false).
*/
public FetchGroup getFetchGroup() {
return fetchGroup;
}
/**
* INTERNAL:
* Initialize fetch group
*/
public void initializeFetchGroup() {
if (fetchGroup != null) {
//fetch group already set.
return;
}
//not explicitly set dynamically fetch group
if (fetchGroupName != null) {//set pre-defined named group
fetchGroup = getDescriptor().getFetchGroupManager().getFetchGroup(fetchGroupName);
if (fetchGroup == null) {
//named fetch group is not defined in the descriptor
throw QueryException.fetchGroupNotDefinedInDescriptor(fetchGroupName);
}
} else {//not set fecth group at all
//use the default fetch group if not explicitly turned off
if (shouldUseDefaultFetchGroup()) {
fetchGroup = getDescriptor().getDefaultFetchGroup();
}
}
}
/**
* Set a dynamic (use case) fetch group to the query.
*/
public void setFetchGroup(FetchGroup newFetchGroup) {
fetchGroup = newFetchGroup;
}
/**
* Set a descriptor-level pre-defined named fetch group to the query.
*/
public void setFetchGroupName(String groupName) {
//nullify the fecth group refernce as one query can only has one fetch group.
fetchGroup = null;
fetchGroupName = groupName;
}
/**
* Return the fetch group name set in the query.
*/
public String getFetchGroupName() {
return fetchGroupName;
}
/**
* Return false if the query does not use the default fetch group defined in the descriptor level.
*/
public boolean shouldUseDefaultFetchGroup() {
return shouldUseDefaultFetchGroup;
}
/**
* Set false if the user does not want to use the default fetch group defined in the descriptor level.
*/
public void setShouldUseDefaultFetchGroup(boolean shouldUseDefaultFetchGroup) {
this.shouldUseDefaultFetchGroup = shouldUseDefaultFetchGroup;
}
/**
* INTERNAL:
* Return if fetch group attributes.
*/
public boolean hasFetchGroupAttributeExpressions() {
return (getFetchGroup() != null) && (getFetchGroup().hasFetchGroupAttributeExpressions());
}
/**
* INTERNAL:
* Return if fetch group attribute.
*/
public boolean isFetchGroupAttribute(String attributeName) {
if (getFetchGroup() == null) {
//every attribute is fetched already
return true;
}
return getFetchGroup().getAttributes().contains(attributeName);
}
}