// $Id: QueryLoader.java 11115 2007-01-30 14:29:39Z steve.ebersole@jboss.com $
package org.hibernate.loader.hql;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.hibernate.HibernateException;
import org.hibernate.LockMode;
import org.hibernate.QueryException;
import org.hibernate.ScrollableResults;
import org.hibernate.dialect.Dialect;
import org.hibernate.engine.QueryParameters;
import org.hibernate.engine.SessionFactoryImplementor;
import org.hibernate.engine.SessionImplementor;
import org.hibernate.event.EventSource;
import org.hibernate.exception.JDBCExceptionHelper;
import org.hibernate.hql.HolderInstantiator;
import org.hibernate.hql.ast.QueryTranslatorImpl;
import org.hibernate.hql.ast.tree.FromElement;
import org.hibernate.hql.ast.tree.SelectClause;
import org.hibernate.hql.ast.tree.QueryNode;
import org.hibernate.impl.IteratorImpl;
import org.hibernate.loader.BasicLoader;
import org.hibernate.param.ParameterSpecification;
import org.hibernate.persister.collection.CollectionPersister;
import org.hibernate.persister.collection.QueryableCollection;
import org.hibernate.persister.entity.Loadable;
import org.hibernate.persister.entity.Queryable;
import org.hibernate.persister.entity.Lockable;
import org.hibernate.transform.ResultTransformer;
import org.hibernate.type.EntityType;
import org.hibernate.type.Type;
import org.hibernate.util.ArrayHelper;
/**
* A delegate that implements the Loader part of QueryTranslator.
*
* @author josh
*/
public class QueryLoader extends BasicLoader {
/**
* The query translator that is delegating to this object.
*/
private QueryTranslatorImpl queryTranslator;
private Queryable[] entityPersisters;
private String[] entityAliases;
private String[] sqlAliases;
private String[] sqlAliasSuffixes;
private boolean[] includeInSelect;
private String[] collectionSuffixes;
private boolean hasScalars;
private String[][] scalarColumnNames;
//private Type[] sqlResultTypes;
private Type[] queryReturnTypes;
private final Map sqlAliasByEntityAlias = new HashMap(8);
private EntityType[] ownerAssociationTypes;
private int[] owners;
private boolean[] entityEagerPropertyFetches;
private int[] collectionOwners;
private QueryableCollection[] collectionPersisters;
private int selectLength;
private ResultTransformer selectNewTransformer;
private String[] queryReturnAliases;
private LockMode[] defaultLockModes;
/**
* Creates a new Loader implementation.
*
* @param queryTranslator The query translator that is the delegator.
* @param factory The factory from which this loader is being created.
* @param selectClause The AST representing the select clause for loading.
*/
public QueryLoader(
final QueryTranslatorImpl queryTranslator,
final SessionFactoryImplementor factory,
final SelectClause selectClause) {
super( factory );
this.queryTranslator = queryTranslator;
initialize( selectClause );
postInstantiate();
}
private void initialize(SelectClause selectClause) {
List fromElementList = selectClause.getFromElementsForLoad();
hasScalars = selectClause.isScalarSelect();
scalarColumnNames = selectClause.getColumnNames();
//sqlResultTypes = selectClause.getSqlResultTypes();
queryReturnTypes = selectClause.getQueryReturnTypes();
selectNewTransformer = HolderInstantiator.createSelectNewTransformer(
selectClause.getConstructor(),
selectClause.isMap(),
selectClause.isList());
queryReturnAliases = selectClause.getQueryReturnAliases();
List collectionFromElements = selectClause.getCollectionFromElements();
if ( collectionFromElements != null && collectionFromElements.size()!=0 ) {
int length = collectionFromElements.size();
collectionPersisters = new QueryableCollection[length];
collectionOwners = new int[length];
collectionSuffixes = new String[length];
for ( int i=0; i<length; i++ ) {
FromElement collectionFromElement = (FromElement) collectionFromElements.get(i);
collectionPersisters[i] = collectionFromElement.getQueryableCollection();
collectionOwners[i] = fromElementList.indexOf( collectionFromElement.getOrigin() );
// collectionSuffixes[i] = collectionFromElement.getColumnAliasSuffix();
// collectionSuffixes[i] = Integer.toString( i ) + "_";
collectionSuffixes[i] = collectionFromElement.getCollectionSuffix();
}
}
int size = fromElementList.size();
entityPersisters = new Queryable[size];
entityEagerPropertyFetches = new boolean[size];
entityAliases = new String[size];
sqlAliases = new String[size];
sqlAliasSuffixes = new String[size];
includeInSelect = new boolean[size];
owners = new int[size];
ownerAssociationTypes = new EntityType[size];
for ( int i = 0; i < size; i++ ) {
final FromElement element = ( FromElement ) fromElementList.get( i );
entityPersisters[i] = ( Queryable ) element.getEntityPersister();
if ( entityPersisters[i] == null ) {
throw new IllegalStateException( "No entity persister for " + element.toString() );
}
entityEagerPropertyFetches[i] = element.isAllPropertyFetch();
sqlAliases[i] = element.getTableAlias();
entityAliases[i] = element.getClassAlias();
sqlAliasByEntityAlias.put( entityAliases[i], sqlAliases[i] );
// TODO should we just collect these like with the collections above?
sqlAliasSuffixes[i] = ( size == 1 ) ? "" : Integer.toString( i ) + "_";
// sqlAliasSuffixes[i] = element.getColumnAliasSuffix();
includeInSelect[i] = !element.isFetch();
if ( includeInSelect[i] ) {
selectLength++;
}
owners[i] = -1; //by default
if ( element.isFetch() ) {
if ( element.isCollectionJoin() || element.getQueryableCollection() != null ) {
// This is now handled earlier in this method.
}
else if ( element.getDataType().isEntityType() ) {
EntityType entityType = ( EntityType ) element.getDataType();
if ( entityType.isOneToOne() ) {
owners[i] = fromElementList.indexOf( element.getOrigin() );
}
ownerAssociationTypes[i] = entityType;
}
}
}
//NONE, because its the requested lock mode, not the actual!
defaultLockModes = ArrayHelper.fillArray(LockMode.NONE, size);
}
// -- Loader implementation --
public final void validateScrollability() throws HibernateException {
queryTranslator.validateScrollability();
}
protected boolean needsFetchingScroll() {
return queryTranslator.containsCollectionFetches();
}
public Loadable[] getEntityPersisters() {
return entityPersisters;
}
public String[] getAliases() {
return sqlAliases;
}
public String[] getSqlAliasSuffixes() {
return sqlAliasSuffixes;
}
public String[] getSuffixes() {
return getSqlAliasSuffixes();
}
public String[] getCollectionSuffixes() {
return collectionSuffixes;
}
protected String getQueryIdentifier() {
return queryTranslator.getQueryIdentifier();
}
/**
* The SQL query string to be called.
*/
protected String getSQLString() {
return queryTranslator.getSQLString();
}
/**
* An (optional) persister for a collection to be initialized; only collection loaders
* return a non-null value
*/
protected CollectionPersister[] getCollectionPersisters() {
return collectionPersisters;
}
protected int[] getCollectionOwners() {
return collectionOwners;
}
protected boolean[] getEntityEagerPropertyFetches() {
return entityEagerPropertyFetches;
}
/**
* An array of indexes of the entity that owns a one-to-one association
* to the entity at the given index (-1 if there is no "owner")
*/
protected int[] getOwners() {
return owners;
}
protected EntityType[] getOwnerAssociationTypes() {
return ownerAssociationTypes;
}
// -- Loader overrides --
protected boolean isSubselectLoadingEnabled() {
return hasSubselectLoadableCollections();
}
/**
* @param lockModes a collection of lock modes specified dynamically via the Query interface
*/
protected LockMode[] getLockModes(Map lockModes) {
if ( lockModes==null || lockModes.size()==0 ) {
return defaultLockModes;
}
else {
// unfortunately this stuff can't be cached because
// it is per-invocation, not constant for the
// QueryTranslator instance
LockMode[] lockModeArray = new LockMode[entityAliases.length];
for ( int i = 0; i < entityAliases.length; i++ ) {
LockMode lockMode = (LockMode) lockModes.get( entityAliases[i] );
if ( lockMode == null ) {
//NONE, because its the requested lock mode, not the actual!
lockMode = LockMode.NONE;
}
lockModeArray[i] = lockMode;
}
return lockModeArray;
}
}
protected String applyLocks(String sql, Map lockModes, Dialect dialect) throws QueryException {
if ( lockModes == null || lockModes.size() == 0 ) {
return sql;
}
// can't cache this stuff either (per-invocation)
// we are given a map of user-alias -> lock mode
// create a new map of sql-alias -> lock mode
final Map aliasedLockModes = new HashMap();
final Map keyColumnNames = dialect.forUpdateOfColumns() ? new HashMap() : null;
final Iterator iter = lockModes.entrySet().iterator();
while ( iter.hasNext() ) {
Map.Entry me = ( Map.Entry ) iter.next();
final String userAlias = ( String ) me.getKey();
final String drivingSqlAlias = ( String ) sqlAliasByEntityAlias.get( userAlias );
if ( drivingSqlAlias == null ) {
throw new IllegalArgumentException( "could not locate alias to apply lock mode : " + userAlias );
}
// at this point we have (drivingSqlAlias) the SQL alias of the driving table
// corresponding to the given user alias. However, the driving table is not
// (necessarily) the table against which we want to apply locks. Mainly,
// the exception case here is joined-subclass hierarchies where we instead
// want to apply the lock against the root table (for all other strategies,
// it just happens that driving and root are the same).
final QueryNode select = ( QueryNode ) queryTranslator.getSqlAST();
final Lockable drivingPersister = ( Lockable ) select.getFromClause().getFromElement( userAlias ).getQueryable();
final String sqlAlias = drivingPersister.getRootTableAlias( drivingSqlAlias );
aliasedLockModes.put( sqlAlias, me.getValue() );
if ( keyColumnNames != null ) {
keyColumnNames.put( sqlAlias, drivingPersister.getRootTableIdentifierColumnNames() );
}
}
return dialect.applyLocksToSql( sql, aliasedLockModes, keyColumnNames );
}
protected boolean upgradeLocks() {
return true;
}
private boolean hasSelectNew() {
return selectNewTransformer!=null;
}
protected Object getResultColumnOrRow(Object[] row, ResultTransformer transformer, ResultSet rs, SessionImplementor session)
throws SQLException, HibernateException {
row = toResultRow( row );
boolean hasTransform = hasSelectNew() || transformer!=null;
if ( hasScalars ) {
String[][] scalarColumns = scalarColumnNames;
int queryCols = queryReturnTypes.length;
if ( !hasTransform && queryCols == 1 ) {
return queryReturnTypes[0].nullSafeGet( rs, scalarColumns[0], session, null );
}
else {
row = new Object[queryCols];
for ( int i = 0; i < queryCols; i++ ) {
row[i] = queryReturnTypes[i].nullSafeGet( rs, scalarColumns[i], session, null );
}
return row;
}
}
else if ( !hasTransform ) {
return row.length == 1 ? row[0] : row;
}
else {
return row;
}
}
protected List getResultList(List results, ResultTransformer resultTransformer) throws QueryException {
// meant to handle dynamic instantiation queries...
HolderInstantiator holderInstantiator = HolderInstantiator.getHolderInstantiator(selectNewTransformer, resultTransformer, queryReturnAliases);
if ( holderInstantiator.isRequired() ) {
for ( int i = 0; i < results.size(); i++ ) {
Object[] row = ( Object[] ) results.get( i );
Object result = holderInstantiator.instantiate(row);
results.set( i, result );
}
if(!hasSelectNew() && resultTransformer!=null) {
return resultTransformer.transformList(results);
} else {
return results;
}
} else {
return results;
}
}
// --- Query translator methods ---
public List list(
SessionImplementor session,
QueryParameters queryParameters) throws HibernateException {
checkQuery( queryParameters );
return list( session, queryParameters, queryTranslator.getQuerySpaces(), queryReturnTypes );
}
private void checkQuery(QueryParameters queryParameters) {
if ( hasSelectNew() && queryParameters.getResultTransformer() != null ) {
throw new QueryException( "ResultTransformer is not allowed for 'select new' queries." );
}
}
public Iterator iterate(
QueryParameters queryParameters,
EventSource session) throws HibernateException {
checkQuery( queryParameters );
final boolean stats = session.getFactory().getStatistics().isStatisticsEnabled();
long startTime = 0;
if ( stats ) {
startTime = System.currentTimeMillis();
}
try {
final PreparedStatement st = prepareQueryStatement( queryParameters, false, session );
if(queryParameters.isCallable()) {
throw new QueryException("iterate() not supported for callable statements");
}
final ResultSet rs = getResultSet(st, queryParameters.hasAutoDiscoverScalarTypes(), false, queryParameters.getRowSelection(), session);
final Iterator result = new IteratorImpl(
rs,
st,
session,
queryReturnTypes,
queryTranslator.getColumnNames(),
HolderInstantiator.getHolderInstantiator(selectNewTransformer, queryParameters.getResultTransformer(), queryReturnAliases)
);
if ( stats ) {
session.getFactory().getStatisticsImplementor().queryExecuted(
// "HQL: " + queryTranslator.getQueryString(),
getQueryIdentifier(),
0,
System.currentTimeMillis() - startTime
);
}
return result;
}
catch ( SQLException sqle ) {
throw JDBCExceptionHelper.convert(
getFactory().getSQLExceptionConverter(),
sqle,
"could not execute query using iterate",
getSQLString()
);
}
}
public ScrollableResults scroll(
final QueryParameters queryParameters,
final SessionImplementor session) throws HibernateException {
checkQuery( queryParameters );
return scroll( queryParameters, queryReturnTypes, HolderInstantiator.getHolderInstantiator(selectNewTransformer, queryParameters.getResultTransformer(), queryReturnAliases), session );
}
// -- Implementation private methods --
private Object[] toResultRow(Object[] row) {
if ( selectLength == row.length ) {
return row;
}
else {
Object[] result = new Object[selectLength];
int j = 0;
for ( int i = 0; i < row.length; i++ ) {
if ( includeInSelect[i] ) {
result[j++] = row[i];
}
}
return result;
}
}
/**
* Returns the locations of all occurrences of the named parameter.
*/
public int[] getNamedParameterLocs(String name) throws QueryException {
return queryTranslator.getParameterTranslations().getNamedParameterSqlLocations( name );
}
/**
* We specifically override this method here, because in general we know much more
* about the parameters and their appropriate bind positions here then we do in
* our super because we track them explciitly here through the ParameterSpecification
* interface.
*
* @param queryParameters The encapsulation of the parameter values to be bound.
* @param startIndex The position from which to start binding parameter values.
* @param session The originating session.
* @return The number of JDBC bind positions actually bound during this method execution.
* @throws SQLException Indicates problems performing the binding.
*/
protected int bindParameterValues(
final PreparedStatement statement,
final QueryParameters queryParameters,
final int startIndex,
final SessionImplementor session) throws SQLException {
int position = bindFilterParameterValues( statement, queryParameters, startIndex, session );
List parameterSpecs = queryTranslator.getSqlAST().getWalker().getParameters();
Iterator itr = parameterSpecs.iterator();
while ( itr.hasNext() ) {
ParameterSpecification spec = ( ParameterSpecification ) itr.next();
position += spec.bind( statement, queryParameters, session, position );
}
return position - startIndex;
}
private int bindFilterParameterValues(
PreparedStatement st,
QueryParameters queryParameters,
int position,
SessionImplementor session) throws SQLException {
// todo : better to handle dynamic filters through implicit DynamicFilterParameterSpecification
// see the discussion there in DynamicFilterParameterSpecification's javadocs as to why
// it is currently not done that way.
int filteredParamCount = queryParameters.getFilteredPositionalParameterTypes() == null
? 0
: queryParameters.getFilteredPositionalParameterTypes().length;
int nonfilteredParamCount = queryParameters.getPositionalParameterTypes() == null
? 0
: queryParameters.getPositionalParameterTypes().length;
int filterParamCount = filteredParamCount - nonfilteredParamCount;
for ( int i = 0; i < filterParamCount; i++ ) {
Type type = queryParameters.getFilteredPositionalParameterTypes()[i];
Object value = queryParameters.getFilteredPositionalParameterValues()[i];
type.nullSafeSet( st, value, position, session );
position += type.getColumnSpan( getFactory() );
}
return position;
}
}
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