org.apache.calcite.adapter.elasticsearch.ElasticsearchSchemaFactory.java Source code

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Here is the source code for org.apache.calcite.adapter.elasticsearch.ElasticsearchSchemaFactory.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to you 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.
 */
package org.apache.calcite.adapter.elasticsearch;

import org.apache.calcite.schema.Schema;
import org.apache.calcite.schema.SchemaFactory;
import org.apache.calcite.schema.SchemaPlus;

import org.apache.http.HttpHost;

import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.google.common.base.Preconditions;

import org.elasticsearch.client.RestClient;

import java.io.IOException;
import java.util.LinkedHashSet;
import java.util.Map;
import java.util.Objects;
import java.util.Set;

/**
 * Factory that creates an {@link ElasticsearchSchema}.
 *
 * <p>Allows a custom schema to be included in a model.json file.
 */
@SuppressWarnings("UnusedDeclaration")
public class ElasticsearchSchemaFactory implements SchemaFactory {

    public ElasticsearchSchemaFactory() {
    }

    @Override
    public Schema create(SchemaPlus parentSchema, String name, Map<String, Object> operand) {

        final Map map = (Map) operand;

        final ObjectMapper mapper = new ObjectMapper();
        mapper.configure(JsonParser.Feature.ALLOW_SINGLE_QUOTES, true);

        try {
            final Map<String, Integer> coordinates = mapper.readValue((String) map.get("coordinates"),
                    new TypeReference<Map<String, Integer>>() {
                    });

            final RestClient client = connect(coordinates);

            final Map<String, String> userConfig = mapper.readValue((String) map.get("userConfig"),
                    new TypeReference<Map<String, String>>() {
                    });

            final String index = (String) map.get("index");
            Preconditions.checkArgument(index != null, "index is missing in configuration");
            return new ElasticsearchSchema(client, new ObjectMapper(), index);
        } catch (IOException e) {
            throw new RuntimeException("Cannot parse values from json", e);
        }
    }

    /**
     * Builds elastic rest client from user configuration
     * @param coordinates list of {@code hostname/port} to connect to
     * @return newly initialized low-level rest http client for ES
     */
    private static RestClient connect(Map<String, Integer> coordinates) {
        Objects.requireNonNull(coordinates, "coordinates");
        Preconditions.checkArgument(!coordinates.isEmpty(), "no ES coordinates specified");
        final Set<HttpHost> set = new LinkedHashSet<>();
        for (Map.Entry<String, Integer> entry : coordinates.entrySet()) {
            set.add(new HttpHost(entry.getKey(), entry.getValue()));
        }

        return RestClient.builder(set.toArray(new HttpHost[0])).build();
    }

}

// End ElasticsearchSchemaFactory.java