elasticsearch/native/src/main/java/org/apache/metamodel/elasticsearch/nativeclient/ElasticSearchDropTableBuilder.java

/**
 * 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.metamodel.elasticsearch.nativeclient;

import java.lang.reflect.Method;

import org.apache.metamodel.MetaModelException;
import org.apache.metamodel.drop.AbstractTableDropBuilder;
import org.apache.metamodel.drop.TableDropBuilder;
import org.apache.metamodel.schema.MutableSchema;
import org.apache.metamodel.schema.Table;
import org.elasticsearch.action.admin.indices.mapping.delete.DeleteMappingRequestBuilder;
import org.elasticsearch.action.admin.indices.mapping.delete.DeleteMappingResponse;
import org.elasticsearch.client.Client;
import org.elasticsearch.client.IndicesAdminClient;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * {@link TableDropBuilder} for dropping tables (document types) in an
 * ElasticSearch index.
 */
final class ElasticSearchDropTableBuilder extends AbstractTableDropBuilder {

    private static final Logger logger = LoggerFactory.getLogger(ElasticSearchDropTableBuilder.class);

    private final ElasticSearchUpdateCallback _updateCallback;

    public ElasticSearchDropTableBuilder(ElasticSearchUpdateCallback updateCallback, Table table) {
        super(table);
        _updateCallback = updateCallback;
    }

    @Override
    public void execute() throws MetaModelException {
        final ElasticSearchDataContext dataContext = _updateCallback.getDataContext();
        final Table table = getTable();
        final String documentType = table.getName();
        logger.info("Deleting mapping / document type: {}", documentType);
        final Client client = dataContext.getElasticSearchClient();
        final IndicesAdminClient indicesAdminClient = client.admin().indices();
        final String indexName = dataContext.getIndexName();

        final DeleteMappingRequestBuilder requestBuilder = new DeleteMappingRequestBuilder(indicesAdminClient)
                .setIndices(indexName);
        setType(requestBuilder, documentType);

        final DeleteMappingResponse result = requestBuilder.execute().actionGet();
        logger.debug("Delete mapping response: acknowledged={}", result.isAcknowledged());

        final MutableSchema schema = (MutableSchema) table.getSchema();
        schema.removeTable(table);
    }

    /**
     * Invokes the {@link DeleteMappingRequestBuilder#setType(String...)} method
     * using reflection. This is done because the API of ElasticSearch was
     * changed and the method signature differes between different versions.
     * 
     * @param requestBuilder
     * @param documentType
     */
    private void setType(DeleteMappingRequestBuilder requestBuilder, String documentType) {
        Object argument;
        Method method;
        try {
            try {
                method = requestBuilder.getClass().getDeclaredMethod("setType", String[].class);
                argument = new String[] {documentType};
            } catch (NoSuchMethodException e) {
                logger.debug("No setType(String[]) method found, trying with a single String instead", e);
                method = requestBuilder.getClass().getDeclaredMethod("setType", String.class);
                argument = documentType;
            }
        } catch (Exception e) {
            logger.error("Failed to resolve DeleteMappingRequestBuilder.setType(...) method", e);
            throw new IllegalStateException("Failed to resolve DeleteMappingRequestBuilder.setType(...) method", e);
        }
        try {
            method.setAccessible(true);
            method.invoke(requestBuilder, argument);
        } catch (Exception e) {
            logger.error("Failed to invoke {}", method, e);
            throw new IllegalStateException("Failed to invoke " + method, e);
        }
    }
}