com.blazebit.persistence.criteria.impl.path.SingularAttributeJoin Maven / Gradle / Ivy
/*
* Copyright 2014 - 2020 Blazebit.
*
* 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.blazebit.persistence.criteria.impl.path;
import com.blazebit.persistence.criteria.impl.BlazeCriteriaBuilderImpl;
import com.blazebit.persistence.criteria.impl.RenderContext;
import com.blazebit.persistence.criteria.impl.expression.SubqueryExpression;
import javax.persistence.criteria.Expression;
import javax.persistence.criteria.JoinType;
import javax.persistence.criteria.Predicate;
import javax.persistence.metamodel.Attribute;
import javax.persistence.metamodel.Bindable;
import javax.persistence.metamodel.EntityType;
import javax.persistence.metamodel.ManagedType;
import javax.persistence.metamodel.PluralAttribute;
import javax.persistence.metamodel.SingularAttribute;
import javax.persistence.metamodel.Type;
/**
* @author Christian Beikov
* @since 1.2.0
*/
public class SingularAttributeJoin extends AbstractJoin {
private static final long serialVersionUID = 1L;
private final Bindable model;
private SingularAttributeJoin(BlazeCriteriaBuilderImpl criteriaBuilder, SingularAttributeJoin original, EntityType treatType) {
super(criteriaBuilder, original, treatType);
this.model = treatType;
}
@SuppressWarnings({"unchecked"})
public SingularAttributeJoin(BlazeCriteriaBuilderImpl criteriaBuilder, Class javaType, AbstractPath pathSource, SingularAttribute joinAttribute, JoinType joinType) {
super(criteriaBuilder, javaType, pathSource, joinAttribute, joinType);
this.model = (Bindable) (Attribute.PersistentAttributeType.EMBEDDED == joinAttribute
.getPersistentAttributeType() ? joinAttribute : criteriaBuilder.getEntityMetamodel().managedType(javaType));
}
@Override
@SuppressWarnings({"unchecked"})
public SingularAttribute getAttribute() {
return (SingularAttribute) super.getAttribute();
}
@Override
public SingularAttributeJoin correlateTo(SubqueryExpression subquery) {
return (SingularAttributeJoin) super.correlateTo(subquery);
}
@Override
@SuppressWarnings({"unchecked"})
protected AbstractFrom createCorrelationDelegate() {
return new SingularAttributeJoin(criteriaBuilder, getJavaType(), (AbstractPath) getBasePath(), getAttribute(), getJoinType());
}
@Override
protected boolean isJoinAllowed() {
return true;
}
@Override
@SuppressWarnings({"unchecked"})
protected ManagedType getManagedType() {
Bindable m = getModel();
Bindable.BindableType t = m.getBindableType();
switch (t) {
case ENTITY_TYPE:
return (ManagedType) m;
case SINGULAR_ATTRIBUTE:
final Type joinedAttributeType = ((SingularAttribute) getAttribute()).getType();
if (!(joinedAttributeType instanceof ManagedType)) {
throw new IllegalArgumentException("Joins on '" + getPathExpression() + "' are not allowed");
}
return (ManagedType) joinedAttributeType;
case PLURAL_ATTRIBUTE:
final Type elementType = ((PluralAttribute) getAttribute()).getElementType();
if (!(elementType instanceof ManagedType)) {
throw new IllegalArgumentException("Joins on '" + getPathExpression() + "' are not allowed");
}
return (ManagedType) elementType;
default:
break;
}
return super.getManagedType();
}
@SuppressWarnings("unchecked")
public Bindable getModel() {
if (treatJoinType != null) {
return (Bindable) treatJoinType;
}
return model;
}
/* JPA 2.1 support */
@Override
public SingularAttributeJoin on(Expression restriction) {
super.onExpression(restriction);
return this;
}
@Override
public SingularAttributeJoin on(Predicate... restrictions) {
super.onPredicates(restrictions);
return this;
}
@Override
@SuppressWarnings("unchecked")
public SingularAttributeJoin treatJoin(Class treatType) {
setTreatType(treatType);
return (SingularAttributeJoin) this;
}
@Override
@SuppressWarnings("unchecked")
public SingularAttributeJoin treatAs(Class treatAsType) {
// No need to treat if it is already of the proper subtype
if (treatAsType.isAssignableFrom(getJavaType())) {
return (SingularAttributeJoin) this;
}
return addTreatedPath(new TreatedSingularAttributeJoin(criteriaBuilder, this, getTreatType(treatAsType)));
}
/**
* @author Christian Beikov
* @since 1.2.0
*/
public static class TreatedSingularAttributeJoin extends SingularAttributeJoin implements TreatedPath {
private static final long serialVersionUID = 1L;
private final SingularAttributeJoin treatedJoin;
private final EntityType treatType;
public TreatedSingularAttributeJoin(BlazeCriteriaBuilderImpl criteriaBuilder, SingularAttributeJoin treatedJoin, EntityType treatType) {
super(criteriaBuilder, treatedJoin, treatType);
this.treatedJoin = treatedJoin;
this.treatType = treatType;
}
@Override
protected ManagedType getManagedType() {
return treatType;
}
@Override
public EntityType getTreatType() {
return treatType;
}
@Override
public AbstractPath getTreatedPath() {
return treatedJoin;
}
@Override
public String getAlias() {
return treatedJoin.getAlias();
}
@Override
public String getPathExpression() {
return getAlias();
}
@Override
public void renderPathExpression(RenderContext context) {
render(context);
}
@Override
public void render(RenderContext context) {
prepareAlias(context);
final StringBuilder buffer = context.getBuffer();
buffer.append("TREAT(")
.append(getAlias())
.append(" AS ")
.append(getTreatType().getName())
.append(')');
}
}
}