org.eclipse.persistence.internal.jpa.querydef.JoinImpl Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of eclipselink Show documentation
EclipseLink build based upon Git transaction f2b9fc5
There is a newer version: 5.0.0-B03
/*
 * Copyright (c) 2011, 2020 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0,
 * or the Eclipse Distribution License v. 1.0 which is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
 */

// Contributors:
//     Gordon Yorke - Initial development
//

package org.eclipse.persistence.internal.jpa.querydef;

import java.util.ArrayList;
import java.util.List;

import jakarta.persistence.criteria.Expression;
import jakarta.persistence.criteria.Fetch;
import jakarta.persistence.criteria.From;
import jakarta.persistence.criteria.Join;
import jakarta.persistence.criteria.JoinType;
import jakarta.persistence.criteria.Path;
import jakarta.persistence.criteria.Predicate;
import jakarta.persistence.criteria.Predicate.BooleanOperator;
import jakarta.persistence.metamodel.Attribute;
import jakarta.persistence.metamodel.Bindable;
import jakarta.persistence.metamodel.ManagedType;
import jakarta.persistence.metamodel.Metamodel;

/**
 * 
 * Purpose: Contains the implementation of the Join interface of the JPA
 * criteria API.
 * 

 * Description: This class represents a join of an attribute from a "From"element.
 * 
 *
 * @see jakarta.persistence.criteria Join
 *
 * @author gyorke
 * @since EclipseLink 1.2
 */

public class JoinImpl extends FromImpl implements Join, Fetch {

    protected JoinType joinType;
    protected Expression on;

    public  JoinImpl(Path parentPath, ManagedType managedType, Metamodel metamodel, Class javaClass, org.eclipse.persistence.expressions.Expression expressionNode, Bindable modelArtifact){
        this(parentPath, managedType, metamodel, javaClass, expressionNode, modelArtifact,JoinType.INNER);
    }

    public  JoinImpl(Path parentPath, ManagedType managedType, Metamodel metamodel, Class javaClass, org.eclipse.persistence.expressions.Expression expressionNode, Bindable modelArtifact, JoinType joinType){
        super(parentPath, managedType, metamodel, javaClass, expressionNode, modelArtifact);
        this.joinType = joinType;
    }

    public  JoinImpl(Path parentPath, ManagedType managedType, Metamodel metamodel, Class javaClass, org.eclipse.persistence.expressions.Expression expressionNode, Bindable modelArtifact, JoinType joinType, FromImpl correlatedParent){
        super(parentPath, managedType, metamodel, javaClass, expressionNode, modelArtifact, correlatedParent);
        this.joinType = joinType;
    }

    /**
     * Return the metamodel Attribute corresponding to the join.
     *
     * @return metamodel Attribute type for the join
     */
    @Override
    public Attribute getAttribute(){
        //Only attributes will be stored in this field so it is ok
        //to perform the cast.
        return (Attribute) this.modelArtifact;
    }

    /**
     * Return the parent of the join.
     *
     * @return join parent
     */
    @Override
    public From getParent(){
        // this cast is acceptable as by design the parent of a Join must be a from implementor
        return (From)pathParent;
    }

    /**
     * Return the join type.
     *
     * @return join type
     */
    @Override
    public JoinType getJoinType(){
        return joinType;
    }

    @Override
    protected  Expression buildExpressionForAs(Class type) {
        managedType = metamodel.managedType(type);
        currentNode = currentNode.treat(type);
        return (Expression)this;
    }

    @Override
    public Predicate getOn() {
        if (this.on == null) {
            return null;
        }
        if (((ExpressionImpl)this.on).isPredicate()) return (Predicate)this.on;

        //see queryBuilder.isTrue(this.on);
        List list = new ArrayList();
        list.add(this.on);
        return new CompoundExpressionImpl(this.metamodel, ((InternalSelection)this.on).getCurrentNode().equal(true), list, "equals");
    }

    @Override
    public JoinImpl on(Expression restriction) {
        this.on = restriction;
        org.eclipse.persistence.expressions.Expression onExp = restriction==null? null:((ExpressionImpl)restriction).getCurrentNode();
        ((PathImpl)this.pathParent).getCurrentNode().join(this.currentNode, onExp);

        return this;
    }

    @Override
    public JoinImpl on(Predicate... restrictions) {
        org.eclipse.persistence.expressions.Expression onExp;
        if (restrictions == null || restrictions.length == 0){
            this.on = null;
            onExp = null;
        } else {
            //from criteriaQueryImpl.where(Predicate... restrictions)
            Predicate a = restrictions[0];
            for (int i = 1; i < restrictions.length; ++i){
                org.eclipse.persistence.expressions.Expression currentNode = ((CompoundExpressionImpl)a).getCurrentNode().and(
                        ((CompoundExpressionImpl)restrictions[i]).getCurrentNode());
                ((CompoundExpressionImpl)a).setParentNode(currentNode);
                ((CompoundExpressionImpl)restrictions[i]).setParentNode(currentNode);
                ArrayList list = new ArrayList();
                list.add(a);
                list.add(restrictions[i]);
                a = new PredicateImpl(this.metamodel, currentNode, list, BooleanOperator.AND);
            }
            this.on = a;
            onExp = ((ExpressionImpl)a).getCurrentNode();
        }

        ((PathImpl)this.pathParent).getCurrentNode().join(this.currentNode, onExp);
        return this;
    }

}