AssociationUtils.java

/*
 * Copyright 2017-2020 original authors
 *
 * 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
 *
 * https://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 io.micronaut.data.model;

import io.micronaut.core.annotation.AnnotationMetadata;
import io.micronaut.core.annotation.Internal;
import io.micronaut.data.annotation.Join;
import io.micronaut.data.model.query.JoinPath;

import java.util.Set;
import java.util.regex.Pattern;
import java.util.stream.Collectors;

/**
 * Internal association utilities.
 *
 * @author graemerocher
 * @since 1.0.0
 */
@Internal
public final class AssociationUtils {
    /**
     * The split pattern for camel case.
     */
    static final Pattern CAMEL_CASE_SPLIT_PATTERN = Pattern.compile("(?<!(^|[A-Z]))(?=[A-Z])|(?<!^)(?=[A-Z][a-z])");

    private AssociationUtils() { }

    /**
     * Gets the join paths from the annotation metadata.
     * @param annotationMetadata the annotation metadata
     * @return the join paths, if none defined and not of type FETCH then an empty set
     */
    public static Set<JoinPath> getJoinFetchPaths(AnnotationMetadata annotationMetadata) {
        return getJoinPaths(annotationMetadata).stream()
            .filter(jp -> jp.getJoinType().isFetch() || jp.getJoinType() == Join.Type.DEFAULT)
            .collect(Collectors.toSet());
    }

    /**
     * Gets all the join paths from the annotation metadata.
     * @param annotationMetadata the annotation metadata
     * @return the join paths
     */
    public static Set<JoinPath> getJoinPaths(AnnotationMetadata annotationMetadata) {
        return annotationMetadata.getAnnotationValuesByType(Join.class).stream().map(av -> {
            String path = av.stringValue().orElseThrow(() -> new IllegalStateException("Should not include annotations without a value definition"));
            Join.Type joinType = av.get("type", Join.Type.class).orElse(Join.Type.DEFAULT);
            String alias = av.stringValue("alias").orElse(null);
            return new JoinPath(path, new Association[0], joinType, alias);
        }).collect(Collectors.toSet());
    }

}