org.hibernate.cfg.beanvalidation.HibernateTraversableResolver.java Source code

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Here is the source code for org.hibernate.cfg.beanvalidation.HibernateTraversableResolver.java

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/*
 * 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.cfg.beanvalidation;

import java.lang.annotation.ElementType;
import java.util.HashSet;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import javax.validation.Path;
import javax.validation.TraversableResolver;

import org.hibernate.Hibernate;
import org.hibernate.annotations.common.AssertionFailure;
import org.hibernate.engine.spi.SessionFactoryImplementor;
import org.hibernate.persister.entity.EntityPersister;
import org.hibernate.type.CollectionType;
import org.hibernate.type.CompositeType;
import org.hibernate.type.Type;

/**
 * Use Hibernate metadata to ignore cascade on entities.
 * cascade on embeddable objects or collection of embeddable objects are accepted
 *
 * Also use Hibernate's native isInitialized method call.
 * 
 * @author Emmanuel Bernard
 */
public class HibernateTraversableResolver implements TraversableResolver {
    private Set<String> associations;

    public HibernateTraversableResolver(EntityPersister persister,
            ConcurrentHashMap<EntityPersister, Set<String>> associationsPerEntityPersister,
            SessionFactoryImplementor factory) {
        this.associations = associationsPerEntityPersister.get(persister);
        if (this.associations == null) {
            this.associations = new HashSet<String>();
            addAssociationsToTheSetForAllProperties(persister.getPropertyNames(), persister.getPropertyTypes(), "",
                    factory);
            associationsPerEntityPersister.put(persister, associations);
        }
    }

    private void addAssociationsToTheSetForAllProperties(String[] names, Type[] types, String prefix,
            SessionFactoryImplementor factory) {
        final int length = names.length;
        for (int index = 0; index < length; index++) {
            addAssociationsToTheSetForOneProperty(names[index], types[index], prefix, factory);
        }
    }

    private void addAssociationsToTheSetForOneProperty(String name, Type type, String prefix,
            SessionFactoryImplementor factory) {

        if (type.isCollectionType()) {
            CollectionType collType = (CollectionType) type;
            Type assocType = collType.getElementType(factory);
            addAssociationsToTheSetForOneProperty(name, assocType, prefix, factory);
        }
        //ToOne association
        else if (type.isEntityType() || type.isAnyType()) {
            associations.add(prefix + name);
        } else if (type.isComponentType()) {
            CompositeType componentType = (CompositeType) type;
            addAssociationsToTheSetForAllProperties(componentType.getPropertyNames(), componentType.getSubtypes(),
                    (prefix.isEmpty() ? name : prefix + name) + '.', factory);
        }
    }

    private String getStringBasedPath(Path.Node traversableProperty, Path pathToTraversableObject) {
        StringBuilder path = new StringBuilder();
        for (Path.Node node : pathToTraversableObject) {
            if (node.getName() != null) {
                path.append(node.getName()).append('.');
            }
        }
        if (traversableProperty.getName() == null) {
            throw new AssertionFailure(
                    "TraversableResolver being passed a traversableProperty with null name. pathToTraversableObject: "
                            + path.toString());
        }
        path.append(traversableProperty.getName());

        return path.toString();
    }

    public boolean isReachable(Object traversableObject, Path.Node traversableProperty, Class<?> rootBeanType,
            Path pathToTraversableObject, ElementType elementType) {
        //lazy, don't load
        return Hibernate.isInitialized(traversableObject)
                && Hibernate.isPropertyInitialized(traversableObject, traversableProperty.getName());
    }

    public boolean isCascadable(Object traversableObject, Path.Node traversableProperty, Class<?> rootBeanType,
            Path pathToTraversableObject, ElementType elementType) {
        String path = getStringBasedPath(traversableProperty, pathToTraversableObject);
        return !associations.contains(path);
    }
}