com.evanzeimet.queryinfo.jpa.field.QueryInfoJPAAttributePathBuilder.java Source code

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Here is the source code for com.evanzeimet.queryinfo.jpa.field.QueryInfoJPAAttributePathBuilder.java

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package com.evanzeimet.queryinfo.jpa.field;

/*
 * #%L
 * queryinfo-jpa
 * $Id:$
 * $HeadURL:$
 * %%
 * Copyright (C) 2015 - 2016 Evan Zeimet
 * %%
 * 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.
 * #L%
 */

import static com.evanzeimet.queryinfo.jpa.attribute.QueryInfoAttributeUtils.ENTITY_CONTEXT_REGISTRY_NOT_USED;

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

import javax.persistence.metamodel.Attribute;
import javax.persistence.metamodel.PluralAttribute;
import javax.persistence.metamodel.SingularAttribute;

import org.apache.commons.lang3.StringUtils;

import com.evanzeimet.queryinfo.jpa.attribute.QueryInfoAttributeType;
import com.evanzeimet.queryinfo.jpa.attribute.QueryInfoAttributeUtils;
import com.evanzeimet.queryinfo.jpa.entity.QueryInfoEntityContextRegistry;
import com.evanzeimet.queryinfo.jpa.join.QueryInfoJoinInfo;

public class QueryInfoJPAAttributePathBuilder<R, T> {

    private static final QueryInfoAttributeUtils attributeUtils = new QueryInfoAttributeUtils();

    private final QueryInfoEntityContextRegistry entityContextRegistry;
    private final List<Attribute<?, ?>> attributes;
    private final Class<R> root;

    protected QueryInfoJPAAttributePathBuilder(QueryInfoEntityContextRegistry entityContextRegistry,
            Class<R> root) {
        this.entityContextRegistry = entityContextRegistry;
        this.root = root;
        this.attributes = Collections.emptyList();
    }

    protected QueryInfoJPAAttributePathBuilder(QueryInfoEntityContextRegistry entityContextRegistry, Class<R> root,
            List<Attribute<?, ?>> parents, Attribute<?, ?> attribute) {
        this.entityContextRegistry = entityContextRegistry;
        this.root = root;
        this.attributes = asAttributeList(parents, attribute);
    }

    public <NT> QueryInfoJPAAttributePathBuilder<R, NT> add(PluralAttribute<? super T, ?, NT> attribute) {
        return new QueryInfoJPAAttributePathBuilder<R, NT>(entityContextRegistry, root, attributes, attribute);
    }

    public <NT> QueryInfoJPAAttributePathBuilder<R, NT> add(SingularAttribute<? super T, NT> attribute) {
        return new QueryInfoJPAAttributePathBuilder<R, NT>(entityContextRegistry, root, attributes, attribute);
    }

    protected List<Attribute<?, ?>> asAttributeList(Attribute<?, ?> attributeInfo) {
        List<Attribute<?, ?>> parents = Collections.emptyList();
        return asAttributeList(parents, attributeInfo);
    }

    protected List<Attribute<?, ?>> asAttributeList(List<Attribute<?, ?>> parents, Attribute<?, ?> attribute) {
        int attributeCount = (parents.size() + 1);
        List<Attribute<?, ?>> result = new ArrayList<>(attributeCount);

        result.addAll(parents);
        result.add(attribute);

        return result;
    }

    public List<String> buildList() {
        return buildList(QueryInfoAttributeUtils.ATTRIBUTE_TYPE_NOT_SPECIFIED);
    }

    public List<String> buildList(QueryInfoAttributeType leafAttributeType) {
        List<String> result;

        if (attributes == null || attributes.isEmpty()) {
            result = Collections.emptyList();
        } else {
            int attributeCount = attributes.size();
            result = new ArrayList<>(attributeCount);

            int joinCount = (attributeCount - 1);
            Class<?> nextAttributeHost = root;

            for (int attributeIndex = 0; attributeIndex < joinCount; attributeIndex++) {
                Attribute<?, ?> attribute = attributes.get(attributeIndex);

                String joinAttributeName = getJoinAttributeName(nextAttributeHost, attribute);
                result.add(joinAttributeName);

                nextAttributeHost = getAttributeJoinedType(attribute);
            }

            Attribute<?, ?> attribute = attributes.get(attributeCount - 1);

            String leafAttributeName = getLeafAttributeName(nextAttributeHost, attribute, leafAttributeType);

            result.add(leafAttributeName);
        }

        return result;
    }

    public String buildString() {
        return buildString(QueryInfoAttributeUtils.ATTRIBUTE_TYPE_NOT_SPECIFIED);
    }

    public String buildString(QueryInfoAttributeType leafAttributeType) {
        List<String> attributeNames = buildList(leafAttributeType);
        return StringUtils.join(attributeNames, ".");
    }

    public QueryInfoJPAAttributePathBuilder<R, R> clear() {
        return new QueryInfoJPAAttributePathBuilder<R, R>(entityContextRegistry, root);
    }

    public static RootBuilder create() {
        return create(ENTITY_CONTEXT_REGISTRY_NOT_USED);
    }

    public static RootBuilder create(QueryInfoEntityContextRegistry entityContextRegistry) {
        return new RootBuilder(entityContextRegistry);
    }

    protected Class<?> getAttributeJoinedType(Attribute<?, ?> attribute) {
        Class<?> result;

        if (attribute instanceof PluralAttribute<?, ?, ?>) {
            PluralAttribute<?, ?, ?> pluralAttribute = ((PluralAttribute<?, ?, ?>) attribute);
            result = pluralAttribute.getBindableJavaType();
        } else {
            result = attribute.getJavaType();
        }

        return result;
    }

    @SuppressWarnings("unchecked")
    protected <H> QueryInfoFieldInfo getFieldInfo(Class<?> attributeHost, Attribute<?, ?> attribute) {
        return attributeUtils.getFieldInfo(entityContextRegistry, (Class<H>) attributeHost,
                (Attribute<? super H, ?>) attribute);
    }

    @SuppressWarnings("unchecked")
    protected <H> String getJoinAttributeName(Class<?> attributeHost, Attribute<?, ?> attribute) {
        return attributeUtils.getJoinAttributeName(entityContextRegistry, (Class<H>) attributeHost,
                (Attribute<? super H, ?>) attribute);
    }

    @SuppressWarnings("unchecked")
    protected <H> QueryInfoJoinInfo getJoinInfo(Class<?> attributeHost, Attribute<?, ?> attribute) {
        return attributeUtils.getJoinInfo(entityContextRegistry, (Class<H>) attributeHost,
                (Attribute<? super H, ?>) attribute);
    }

    @SuppressWarnings("unchecked")
    protected <H> String getLeafAttributeName(Class<?> attributeHost, Attribute<?, ?> attribute,
            QueryInfoAttributeType attributeType) {
        return attributeUtils.getAttributeName(entityContextRegistry, (Class<H>) attributeHost,
                (Attribute<? super H, ?>) attribute, attributeType);
    }

    public static class RootBuilder {

        private final QueryInfoEntityContextRegistry entityContextRegistry;

        protected RootBuilder(QueryInfoEntityContextRegistry entityContextRegistry) {
            this.entityContextRegistry = entityContextRegistry;
        }

        public <T> QueryInfoJPAAttributePathBuilder<T, T> root(Class<T> root) {
            return new QueryInfoJPAAttributePathBuilder<T, T>(entityContextRegistry, root);
        }

    }
}