Example usage for javax.persistence.metamodel ManagedType getDeclaredPluralAttributes

Introduction

In this page you can find the example usage for javax.persistence.metamodel ManagedType getDeclaredPluralAttributes.

Prototype

Set<PluralAttribute<X, ?, ?>> getDeclaredPluralAttributes();

Source Link

Document

Return all multi-valued attributes (Collection-, Set-, List-, and Map-valued attributes) declared by the managed type.

Usage

From source file:net.sf.gazpachoquest.qbe.ByExampleSpecification.java

public <T extends Persistable> Specification<T> byExampleOnEntity(final T example, final SearchParameters sp) {
    Validate.notNull(example, "example must not be null");

    return new Specification<T>() {

        @Override// www.  j  a  v a 2  s  . com
        public Predicate toPredicate(final Root<T> rootPath, final CriteriaQuery<?> query,
                final CriteriaBuilder builder) {
            Class<T> type = rootPath.getModel().getBindableJavaType();

            ManagedType<T> mt = em.getMetamodel().entity(type);

            List<Predicate> predicates = new ArrayList<Predicate>();
            predicates.addAll(byExample(mt, rootPath, example, sp, builder));
            predicates.addAll(byExampleOnXToOne(mt, rootPath, example, sp, builder));
            // 1 level deep only
            predicates.addAll(byExampleOnManyToMany(mt, rootPath, example, sp, builder));
            // order by
            query.orderBy(JpaUtil.buildJpaOrders(sp.getOrders(), rootPath, builder));
            return JpaUtil.andPredicate(builder, predicates);
        }

        //https://github.com/jaxio/generated-projects/tree/master/jsf2-spring-conversation/src/main/generated-java/com/jaxio/appli/repository/support

        public <T extends Persistable> List<Predicate> byExample(final ManagedType<T> mt, final Path<T> mtPath,
                final T mtValue, final SearchParameters sp, final CriteriaBuilder builder) {
            List<Predicate> predicates = new ArrayList<Predicate>();
            for (SingularAttribute<? super T, ?> attr : mt.getSingularAttributes()) {
                if (attr.getPersistentAttributeType() == MANY_TO_ONE
                        || attr.getPersistentAttributeType() == ONE_TO_ONE
                        || attr.getPersistentAttributeType() == EMBEDDED
                        || attr.getJavaType().isAssignableFrom(Map.class)) {
                    continue;
                }
                Object attrValue = getValue(mtValue, attr);

                if (attrValue != null) {
                    if (attr.getJavaType() == String.class) {
                        if (isNotEmpty((String) attrValue)) {
                            SingularAttribute<? super T, String> stringAttribute = mt
                                    .getSingularAttribute(attr.getName(), String.class);
                            predicates.add(JpaUtil.stringPredicate(mtPath.get(stringAttribute), attrValue, sp,
                                    builder));
                        }
                    } else {
                        SingularAttribute<? super T, ?> attribute = mt.getSingularAttribute(attr.getName(),
                                attr.getJavaType());
                        // apply equal
                        predicates.add(builder.equal(mtPath.get(attribute), attrValue));
                    }
                }
            }
            return predicates;
        }

        /**
         * Construct a join predicate on collection (eg many to many, List)
         */
        public <T extends Persistable> List<Predicate> byExampleOnManyToMany(final ManagedType<T> mt,
                final Root<T> mtPath, final T mtValue, final SearchParameters sp,
                final CriteriaBuilder builder) {
            List<Predicate> predicates = new ArrayList<Predicate>();
            for (PluralAttribute<T, ?, ?> pa : mt.getDeclaredPluralAttributes()) {
                if (pa.getCollectionType() == PluralAttribute.CollectionType.LIST) {
                    List<?> value = (List<?>) getValue(mtValue, mt.getAttribute(pa.getName()));

                    if (value != null && !value.isEmpty()) {
                        ListJoin<T, ?> join = mtPath.join(mt.getDeclaredList(pa.getName()));
                        predicates.add(join.in(value));
                    }
                }
                if (pa.getCollectionType() == PluralAttribute.CollectionType.SET) {
                    Set<?> value = (Set<?>) getValue(mtValue, mt.getAttribute(pa.getName()));

                    if (value != null && !value.isEmpty()) {
                        SetJoin<T, ?> join = mtPath.join(mt.getDeclaredSet(pa.getName()));
                        predicates.add(join.in(value));
                    }
                }
            }
            return predicates;
        }

        /**
         * Invoke byExample method for each not null x-to-one association
         * when their pk is not set. This allows you
         * to search entities based on an associated entity's properties
         * value.
         */
        @SuppressWarnings("unchecked")
        public <T extends Persistable, M2O extends Persistable> List<Predicate> byExampleOnXToOne(
                final ManagedType<T> mt, final Root<T> mtPath, final T mtValue, final SearchParameters sp,
                final CriteriaBuilder builder) {
            List<Predicate> predicates = new ArrayList<Predicate>();
            for (SingularAttribute<? super T, ?> attr : mt.getSingularAttributes()) {
                if (attr.getPersistentAttributeType() == MANY_TO_ONE
                        || attr.getPersistentAttributeType() == ONE_TO_ONE) { //
                    M2O m2oValue = (M2O) getValue(mtValue, mt.getAttribute(attr.getName()));

                    if (m2oValue != null) {
                        Class<M2O> m2oType = (Class<M2O>) attr.getBindableJavaType();
                        ManagedType<M2O> m2oMt = em.getMetamodel().entity(m2oType);
                        Path<M2O> m2oPath = (Path<M2O>) mtPath.get(attr);
                        predicates.addAll(byExample(m2oMt, m2oPath, m2oValue, sp, builder));
                    }
                }
            }
            return predicates;
        }

        private <T> Object getValue(final T example, final Attribute<? super T, ?> attr) {
            Object value = null;
            try {
                if (attr.getJavaMember() instanceof Method) {
                    value = ((Method) attr.getJavaMember()).invoke(example, new Object[0]);
                } else if (attr.getJavaMember() instanceof Field) {
                    value = ReflectionUtils.getField((Field) attr.getJavaMember(), example);
                }

                if (value instanceof ValueHolderInterface) {
                    value = ((ValueHolderInterface) value).getValue();
                }

            } catch (IllegalAccessException e) {
                throw new RuntimeException(e);
            } catch (InvocationTargetException e) {
                throw new RuntimeException(e);
            }
            return value;
        }

    };

}

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