/*
* Copyright 2015, The Querydsl Team (http://www.querydsl.com/team)
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* http://www.apache.org/licenses/LICENSE-2.0
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.querydsl.jpa.hibernate.sql;
import java.util.List;
import java.util.Map;
import java.util.Set;
import javax.annotation.Nullable;
import org.hibernate.Query;
import org.hibernate.*;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.slf4j.MDC;
import com.google.common.collect.ListMultimap;
import com.google.common.collect.Sets;
import com.mysema.commons.lang.CloseableIterator;
import com.querydsl.core.*;
import com.querydsl.core.NonUniqueResultException;
import com.querydsl.core.types.Expression;
import com.querydsl.core.types.FactoryExpression;
import com.querydsl.jpa.AbstractSQLQuery;
import com.querydsl.jpa.FactoryExpressionTransformer;
import com.querydsl.jpa.NativeSQLSerializer;
import com.querydsl.jpa.ScrollableResultsIterator;
import com.querydsl.jpa.hibernate.DefaultSessionHolder;
import com.querydsl.jpa.hibernate.HibernateUtil;
import com.querydsl.jpa.hibernate.SessionHolder;
import com.querydsl.jpa.hibernate.StatelessSessionHolder;
import com.querydsl.sql.Configuration;
import com.querydsl.sql.SQLSerializer;
/**
* {@code AbstractHibernateSQLQuery} is the base class for Hibernate Native SQL queries
*
* @param <T> result type
* @param <Q> concrete subtype
*
* @author tiwe
*/
public abstract class AbstractHibernateSQLQuery<T, Q extends AbstractHibernateSQLQuery<T, Q>> extends AbstractSQLQuery<T, Q> {
private static final Logger logger = LoggerFactory.getLogger(AbstractHibernateSQLQuery.class);
protected Boolean cacheable, readOnly;
protected String cacheRegion;
protected int fetchSize = 0;
private final SessionHolder session;
protected int timeout = 0;
public AbstractHibernateSQLQuery(Session session, Configuration conf) {
this(new DefaultSessionHolder(session), conf, new DefaultQueryMetadata());
}
public AbstractHibernateSQLQuery(StatelessSession session, Configuration conf) {
this(new StatelessSessionHolder(session), conf, new DefaultQueryMetadata());
}
public AbstractHibernateSQLQuery(SessionHolder session, Configuration conf, QueryMetadata metadata) {
super(metadata, conf);
this.session = session;
}
public Query createQuery() {
return createQuery(false);
}
private Query createQuery(boolean forCount) {
NativeSQLSerializer serializer = (NativeSQLSerializer) serialize(forCount);
String queryString = serializer.toString();
logQuery(queryString, serializer.getConstantToLabel());
org.hibernate.SQLQuery query = session.createSQLQuery(queryString);
// set constants
HibernateUtil.setConstants(query, serializer.getConstantToLabel(), queryMixin.getMetadata().getParams());
if (!forCount) {
ListMultimap<Expression<?>, String> aliases = serializer.getAliases();
Set<String> used = Sets.newHashSet();
// set entity paths
Expression<?> projection = queryMixin.getMetadata().getProjection();
if (projection instanceof FactoryExpression) {
for (Expression<?> expr : ((FactoryExpression<?>) projection).getArgs()) {
if (isEntityExpression(expr)) {
query.addEntity(extractEntityExpression(expr).toString(), expr.getType());
} else if (aliases.containsKey(expr)) {
for (String scalar : aliases.get(expr)) {
if (!used.contains(scalar)) {
query.addScalar(scalar);
used.add(scalar);
break;
}
}
}
}
} else if (isEntityExpression(projection)) {
query.addEntity(extractEntityExpression(projection).toString(), projection.getType());
} else if (aliases.containsKey(projection)) {
for (String scalar : aliases.get(projection)) {
if (!used.contains(scalar)) {
query.addScalar(scalar);
used.add(scalar);
break;
}
}
}
// set result transformer, if projection is a FactoryExpression instance
if (projection instanceof FactoryExpression) {
query.setResultTransformer(new FactoryExpressionTransformer((FactoryExpression<?>) projection));
}
}
if (fetchSize > 0) {
query.setFetchSize(fetchSize);
}
if (timeout > 0) {
query.setTimeout(timeout);
}
if (cacheable != null) {
query.setCacheable(cacheable);
}
if (cacheRegion != null) {
query.setCacheRegion(cacheRegion);
}
if (readOnly != null) {
query.setReadOnly(readOnly);
}
return query;
}
@Override
protected SQLSerializer createSerializer() {
return new NativeSQLSerializer(configuration, true);
}
@SuppressWarnings("unchecked")
@Override
public List<T> fetch() {
try {
return createQuery().list();
} finally {
reset();
}
}
@Override
public CloseableIterator<T> iterate() {
try {
Query query = createQuery();
ScrollableResults results = query.scroll(ScrollMode.FORWARD_ONLY);
return new ScrollableResultsIterator<T>(results);
} finally {
reset();
}
}
@Override
public QueryResults<T> fetchResults() {
// TODO : handle entity projections as well
try {
Query query = createQuery(true);
long total = ((Number) query.uniqueResult()).longValue();
if (total > 0) {
QueryModifiers modifiers = queryMixin.getMetadata().getModifiers();
query = createQuery(false);
@SuppressWarnings("unchecked")
List<T> list = query.list();
return new QueryResults<T>(list, modifiers, total);
} else {
return QueryResults.emptyResults();
}
} finally {
reset();
}
}
protected void logQuery(String queryString, Map<Object, String> parameters) {
if (logger.isDebugEnabled()) {
String normalizedQuery = queryString.replace('\n', ' ');
MDC.put(MDC_QUERY, normalizedQuery);
MDC.put(MDC_PARAMETERS, String.valueOf(parameters));
logger.debug(normalizedQuery);
}
}
protected void cleanupMDC() {
MDC.remove(MDC_QUERY);
MDC.remove(MDC_PARAMETERS);
}
protected void reset() {
cleanupMDC();
}
@SuppressWarnings("unchecked")
@Override
public T fetchOne() {
try {
Query query = createQuery();
return (T) uniqueResult(query);
} finally {
reset();
}
}
@Nullable
private Object uniqueResult(Query query) {
try {
return query.uniqueResult();
} catch (org.hibernate.NonUniqueResultException e) {
throw new NonUniqueResultException();
}
}
/**
* Enable caching of this query result set.
* @param cacheable Should the query results be cacheable?
*/
@SuppressWarnings("unchecked")
public Q setCacheable(boolean cacheable) {
this.cacheable = cacheable;
return (Q) this;
}
/**
* Set the name of the cache region.
* @param cacheRegion the name of a query cache region, or <tt>null</tt>
* for the default query cache
*/
@SuppressWarnings("unchecked")
public Q setCacheRegion(String cacheRegion) {
this.cacheRegion = cacheRegion;
return (Q) this;
}
/**
* Set a fetchJoin size for the underlying JDBC query.
* @param fetchSize the fetchJoin size
*/
@SuppressWarnings("unchecked")
public Q setFetchSize(int fetchSize) {
this.fetchSize = fetchSize;
return (Q) this;
}
/**
* Entities retrieved by this query will be loaded in
* a read-only mode where Hibernate will never dirty-check
* them or make changes persistent.
*
*/
@SuppressWarnings("unchecked")
public Q setReadOnly(boolean readOnly) {
this.readOnly = readOnly;
return (Q) this;
}
/**
* Set a timeout for the underlying JDBC query.
* @param timeout the timeout in seconds
*/
@SuppressWarnings("unchecked")
public Q setTimeout(int timeout) {
this.timeout = timeout;
return (Q) this;
}
@Override
protected void clone(Q query) {
super.clone(query);
cacheable = query.cacheable;
cacheRegion = query.cacheRegion;
fetchSize = query.fetchSize;
readOnly = query.readOnly;
timeout = query.timeout;
}
protected abstract Q clone(SessionHolder session);
public Q clone(Session session) {
return this.clone(new DefaultSessionHolder(session));
}
public Q clone(StatelessSession statelessSession) {
return this.clone(new StatelessSessionHolder(statelessSession));
}
@Override
public Q clone() {
return this.clone(this.session);
}
}