org.springframework.data.elasticsearch.core.ResultsMapper.java Source code

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Here is the source code for org.springframework.data.elasticsearch.core.ResultsMapper.java

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/*
 * Copyright 2013-2019 the original author or 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 org.springframework.data.elasticsearch.core;

import java.io.IOException;
import java.util.Map;

import org.elasticsearch.index.get.GetResult;
import org.elasticsearch.search.SearchHit;
import org.springframework.data.elasticsearch.ElasticsearchException;
import org.springframework.data.projection.ProjectionFactory;
import org.springframework.data.projection.SpelAwareProxyProjectionFactory;
import org.springframework.lang.Nullable;
import org.springframework.util.ClassUtils;
import org.springframework.util.StringUtils;

/**
 * ResultsMapper
 *
 * @author Rizwan Idrees
 * @author Mohsin Husen
 * @author Artur Konczak
 * @author Christoph Strobl
 */
public interface ResultsMapper extends SearchResultMapper, GetResultMapper, MultiGetResultMapper {

    EntityMapper getEntityMapper();

    /**
     * Get the configured {@link ProjectionFactory}. <br />
     * <strong>NOTE</strong> Should be overwritten in implementation to make use of the type cache.
     *
     * @since 3.2
     */
    default ProjectionFactory getProjectionFactory() {
        return new SpelAwareProxyProjectionFactory();
    }

    @Nullable
    default <T> T mapEntity(String source, Class<T> clazz) {

        if (StringUtils.isEmpty(source)) {
            return null;
        }
        try {
            return getEntityMapper().mapToObject(source, clazz);
        } catch (IOException e) {
            throw new ElasticsearchException(
                    "failed to map source [ " + source + "] to class " + clazz.getSimpleName(), e);
        }
    }

    /**
     * Map a single {@link GetResult} to an instance of the given type.
     *
     * @param getResult must not be {@literal null}.
     * @param type must not be {@literal null}.
     * @param <T>
     * @return can be {@literal null} if the {@link GetResult#isSourceEmpty() is empty}.
     * @since 3.2
     */
    @Nullable
    default <T> T mapGetResult(GetResult getResult, Class<T> type) {

        if (getResult.isSourceEmpty()) {
            return null;
        }

        Map<String, Object> source = getResult.getSource();
        if (!source.containsKey("id") || source.get("id") == null) {
            source.put("id", getResult.getId());
        }

        Object mappedResult = getEntityMapper().readObject(source, type);

        if (mappedResult == null) {
            return (T) null;
        }

        if (type.isInterface() || !ClassUtils.isAssignableValue(type, mappedResult)) {
            return getProjectionFactory().createProjection(type, mappedResult);
        }

        return type.cast(mappedResult);
    }

    /**
     * Map a single {@link SearchHit} to an instance of the given type.
     *
     * @param searchHit must not be {@literal null}.
     * @param type must not be {@literal null}.
     * @param <T>
     * @return can be {@literal null} if the {@link SearchHit} does not have {@link SearchHit#hasSource() a source}.
     * @since 3.2
     */
    @Nullable
    default <T> T mapSearchHit(SearchHit searchHit, Class<T> type) {

        if (!searchHit.hasSource()) {
            return null;
        }

        Map<String, Object> source = searchHit.getSourceAsMap();
        if (!source.containsKey("id") || source.get("id") == null) {
            source.put("id", searchHit.getId());
        }

        Object mappedResult = getEntityMapper().readObject(source, type);

        if (mappedResult == null) {
            return null;
        }

        if (type.isInterface()) {
            return getProjectionFactory().createProjection(type, mappedResult);
        }

        return type.cast(mappedResult);
    }
}