/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
 * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
 */
package org.hibernate.query.criteria.internal;

import java.io.Serializable;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import javax.persistence.Tuple;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Expression;
import javax.persistence.criteria.Order;
import javax.persistence.criteria.ParameterExpression;
import javax.persistence.criteria.Predicate;
import javax.persistence.criteria.Root;
import javax.persistence.criteria.Selection;
import javax.persistence.criteria.Subquery;
import javax.persistence.metamodel.EntityType;

import org.hibernate.engine.spi.SessionImplementor;
import org.hibernate.jpa.spi.HibernateEntityManagerImplementor;
import org.hibernate.query.criteria.internal.compile.CompilableCriteria;
import org.hibernate.query.criteria.internal.compile.CriteriaInterpretation;
import org.hibernate.query.criteria.internal.compile.CriteriaQueryTypeQueryAdapter;
import org.hibernate.query.criteria.internal.compile.ImplicitParameterBinding;
import org.hibernate.query.criteria.internal.compile.InterpretedParameterMetadata;
import org.hibernate.query.criteria.internal.compile.RenderingContext;
import org.hibernate.query.spi.QueryImplementor;
import org.hibernate.type.Type;

import org.jboss.logging.Logger;

The Hibernate implementation of the JPA CriteriaQuery contract. Mostly a set of delegation to its internal QueryStructure.
Author:Steve Ebersole
/** * The Hibernate implementation of the JPA {@link CriteriaQuery} contract. Mostly a set of delegation to its * internal {@link QueryStructure}. * * @author Steve Ebersole */
public class CriteriaQueryImpl<T> extends AbstractNode implements CriteriaQuery<T>, CompilableCriteria, Serializable { private static final Logger log = Logger.getLogger( CriteriaQueryImpl.class ); private final Class<T> returnType; private final QueryStructure<T> queryStructure; private List<Order> orderSpecs = Collections.emptyList(); public CriteriaQueryImpl( CriteriaBuilderImpl criteriaBuilder, Class<T> returnType) { super( criteriaBuilder ); this.returnType = returnType; this.queryStructure = new QueryStructure<T>( this, criteriaBuilder ); } @Override public Class<T> getResultType() { return returnType; } // SELECTION ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ @Override public CriteriaQuery<T> distinct(boolean applyDistinction) { queryStructure.setDistinct( applyDistinction ); return this; } @Override public boolean isDistinct() { return queryStructure.isDistinct(); } @Override @SuppressWarnings({ "unchecked" }) public Selection<T> getSelection() { return ( Selection<T> ) queryStructure.getSelection(); } public void applySelection(Selection<? extends T> selection) { queryStructure.setSelection( selection ); } @Override public CriteriaQuery<T> select(Selection<? extends T> selection) { applySelection( selection ); return this; } @Override @SuppressWarnings({ "unchecked" }) public CriteriaQuery<T> multiselect(Selection<?>... selections) { return multiselect( Arrays.asList( selections ) ); } @Override @SuppressWarnings({ "unchecked" }) public CriteriaQuery<T> multiselect(List<Selection<?>> selections) { final Selection<? extends T> selection; if ( Tuple.class.isAssignableFrom( getResultType() ) ) { selection = ( Selection<? extends T> ) criteriaBuilder().tuple( selections ); } else if ( getResultType().isArray() ) { selection = criteriaBuilder().array( getResultType(), selections ); } else if ( Object.class.equals( getResultType() ) ) { switch ( selections.size() ) { case 0: { throw new IllegalArgumentException( "empty selections passed to criteria query typed as Object" ); } case 1: { selection = ( Selection<? extends T> ) selections.get( 0 ); break; } default: { selection = ( Selection<? extends T> ) criteriaBuilder().array( selections ); } } } else { selection = criteriaBuilder().construct( getResultType(), selections ); } applySelection( selection ); return this; } // ROOTS ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ @Override public Set<Root<?>> getRoots() { return queryStructure.getRoots(); } @Override public <X> Root<X> from(EntityType<X> entityType) { return queryStructure.from( entityType ); } @Override public <X> Root<X> from(Class<X> entityClass) { return queryStructure.from( entityClass ); } // RESTRICTION ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ @Override public Predicate getRestriction() { return queryStructure.getRestriction(); } @Override public CriteriaQuery<T> where(Expression<Boolean> expression) { queryStructure.setRestriction( criteriaBuilder().wrap( expression ) ); return this; } @Override public CriteriaQuery<T> where(Predicate... predicates) { // TODO : assuming this should be a conjuntion, but the spec does not say specifically... queryStructure.setRestriction( criteriaBuilder().and( predicates ) ); return this; } // GROUPING ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ @Override public List<Expression<?>> getGroupList() { return queryStructure.getGroupings(); } @Override public CriteriaQuery<T> groupBy(Expression<?>... groupings) { queryStructure.setGroupings( groupings ); return this; } @Override public CriteriaQuery<T> groupBy(List<Expression<?>> groupings) { queryStructure.setGroupings( groupings ); return this; } @Override public Predicate getGroupRestriction() { return queryStructure.getHaving(); } @Override public CriteriaQuery<T> having(Expression<Boolean> expression) { queryStructure.setHaving( criteriaBuilder().wrap( expression ) ); return this; } @Override public CriteriaQuery<T> having(Predicate... predicates) { queryStructure.setHaving( criteriaBuilder().and( predicates ) ); return this; } // ORDERING ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ @Override public List<Order> getOrderList() { return orderSpecs; } @Override public CriteriaQuery<T> orderBy(Order... orders) { if ( orders != null && orders.length > 0 ) { orderSpecs = Arrays.asList( orders ); } else { orderSpecs = Collections.emptyList(); } return this; } @Override public CriteriaQuery<T> orderBy(List<Order> orders) { orderSpecs = orders; return this; } @Override public Set<ParameterExpression<?>> getParameters() { return queryStructure.getParameters(); } @Override public <U> Subquery<U> subquery(Class<U> subqueryType) { return queryStructure.subquery( subqueryType ); } @Override public void validate() { // getRoots() is explicitly supposed to return empty if none defined, no need to check for null if ( getRoots().isEmpty() ) { throw new IllegalStateException( "No criteria query roots were specified" ); } // if there is not an explicit selection, there is an *implicit* selection of the root entity provided only // a single query root was defined. if ( getSelection() == null && !hasImplicitSelection() ) { throw new IllegalStateException( "No explicit selection and an implicit one could not be determined" ); } }
If no explicit selection was defined, we have a condition called an implicit selection if the query specified a single Root and the java type of that root's model is the same as this criteria's result type.
Returns:True if there is an explicit selection; false otherwise.
/** * If no explicit selection was defined, we have a condition called an implicit selection if the query specified * a single {@link Root} and the java type of that {@link Root root's} model is the same as this criteria's * {@link #getResultType() result type}. * * @return True if there is an explicit selection; false otherwise. */
private boolean hasImplicitSelection() { if ( getRoots().size() != 1 ) { return false; } Root root = getRoots().iterator().next(); Class<?> javaType = root.getModel().getJavaType(); if ( javaType != null && javaType != returnType ) { return false; } // if we get here, the query defined no selection but defined a single root of the same type as the // criteria query return, so we use that as the implicit selection // // todo : should we put an implicit marker in the selection to this fact to make later processing easier? return true; } @Override public CriteriaInterpretation interpret(RenderingContext renderingContext) { final StringBuilder jpaqlBuffer = new StringBuilder(); queryStructure.render( jpaqlBuffer, renderingContext ); if ( ! getOrderList().isEmpty() ) { jpaqlBuffer.append( " order by " ); String sep = ""; for ( Order orderSpec : getOrderList() ) { jpaqlBuffer.append( sep ) .append( ( ( Renderable ) orderSpec.getExpression() ).render( renderingContext ) ) .append( orderSpec.isAscending() ? " asc" : " desc" ); sep = ", "; } } final String jpaqlString = jpaqlBuffer.toString(); log.debugf( "Rendered criteria query -> %s", jpaqlString ); return new CriteriaInterpretation() { @Override @SuppressWarnings("unchecked") public QueryImplementor buildCompiledQuery( SessionImplementor entityManager, final InterpretedParameterMetadata parameterMetadata) { final Map<String,Class> implicitParameterTypes = extractTypeMap( parameterMetadata.implicitParameterBindings() ); QueryImplementor<T> jpaqlQuery = entityManager.createQuery( jpaqlString, getResultType(), getSelection(), new HibernateEntityManagerImplementor.QueryOptions() { @Override public List<ValueHandlerFactory.ValueHandler> getValueHandlers() { SelectionImplementor selection = (SelectionImplementor) queryStructure.getSelection(); return selection == null ? null : selection.getValueHandlers(); } @Override public Map<String, Class> getNamedParameterExplicitTypes() { return implicitParameterTypes; } @Override public ResultMetadataValidator getResultMetadataValidator() { return new HibernateEntityManagerImplementor.QueryOptions.ResultMetadataValidator() { @Override public void validate(Type[] returnTypes) { SelectionImplementor selection = (SelectionImplementor) queryStructure.getSelection(); if ( selection != null ) { if ( selection.isCompoundSelection() ) { if ( returnTypes.length != selection.getCompoundSelectionItems().size() ) { throw new IllegalStateException( "Number of return values [" + returnTypes.length + "] did not match expected [" + selection.getCompoundSelectionItems().size() + "]" ); } } else { if ( returnTypes.length > 1 ) { throw new IllegalStateException( "Number of return values [" + returnTypes.length + "] did not match expected [1]" ); } } } } }; } } ); for ( ImplicitParameterBinding implicitParameterBinding : parameterMetadata.implicitParameterBindings() ) { implicitParameterBinding.bind( jpaqlQuery ); } return new CriteriaQueryTypeQueryAdapter( entityManager, jpaqlQuery, parameterMetadata.explicitParameterInfoMap() ); } private Map<String, Class> extractTypeMap(List<ImplicitParameterBinding> implicitParameterBindings) { final HashMap<String,Class> map = new HashMap<String, Class>(); for ( ImplicitParameterBinding implicitParameter : implicitParameterBindings ) { map.put( implicitParameter.getParameterName(), implicitParameter.getJavaType() ); } return map; } }; } }