org.apache.streams.neo4j.http.Neo4jHttpPersistWriter.java Source code

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Here is the source code for org.apache.streams.neo4j.http.Neo4jHttpPersistWriter.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
 *
 *   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.streams.neo4j.http;

import org.apache.streams.components.http.HttpPersistWriterConfiguration;
import org.apache.streams.components.http.persist.SimpleHTTPPostPersistWriter;
import org.apache.streams.config.ComponentConfigurator;
import org.apache.streams.config.StreamsConfigurator;
import org.apache.streams.core.StreamsDatum;
import org.apache.streams.graph.HttpGraphHelper;
import org.apache.streams.graph.QueryGraphHelper;
import org.apache.streams.neo4j.CypherQueryGraphHelper;
import org.apache.streams.jackson.StreamsJacksonMapper;
import org.apache.streams.neo4j.Neo4jConfiguration;
import org.apache.streams.neo4j.Neo4jPersistUtil;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.node.ArrayNode;
import com.fasterxml.jackson.databind.node.ObjectNode;

import org.apache.http.HttpEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.util.EntityUtils;
import org.javatuples.Pair;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;

/**
 * Adds activityobjects as vertices and activities as edges to a graph database with
 * an http rest endpoint (such as neo4j).
 */
public class Neo4jHttpPersistWriter extends SimpleHTTPPostPersistWriter {

    public static final String STREAMS_ID = Neo4jHttpPersistWriter.class.getCanonicalName();

    private static final Logger LOGGER = LoggerFactory.getLogger(Neo4jHttpPersistWriter.class);
    private static final long MAX_WRITE_LATENCY = 1000;

    private Neo4jConfiguration configuration;

    private QueryGraphHelper queryGraphHelper;
    private HttpGraphHelper httpGraphHelper;

    private static ObjectMapper mapper;

    protected final ReadWriteLock lock = new ReentrantReadWriteLock();

    /**
     * GraphHttpPersistWriter constructor - resolve GraphHttpConfiguration from JVM 'graph'.
     */
    public Neo4jHttpPersistWriter() {
        this(new ComponentConfigurator<>(Neo4jConfiguration.class)
                .detectConfiguration(StreamsConfigurator.config.getConfig("neo4j")));
    }

    /**
     * GraphHttpPersistWriter constructor - use supplied GraphHttpConfiguration.
     * @param configuration GraphHttpConfiguration
     */
    public Neo4jHttpPersistWriter(Neo4jConfiguration configuration) {
        super((HttpPersistWriterConfiguration) StreamsJacksonMapper.getInstance()
                .convertValue(configuration, HttpPersistWriterConfiguration.class)
                .withHostname(configuration.getHosts().get(0)));
        super.configuration.setResourcePath("/db/data/transaction/commit/");
        this.configuration = configuration;
    }

    @Override
    protected ObjectNode preparePayload(StreamsDatum entry) throws Exception {

        List<Pair<String, Map<String, Object>>> statements = Neo4jPersistUtil.prepareStatements(entry);

        ObjectNode requestNode = mapper.createObjectNode();
        ArrayNode statementsArray = mapper.createArrayNode();

        for (Pair<String, Map<String, Object>> statement : statements) {
            statementsArray.add(httpGraphHelper.writeData(statement));
        }

        requestNode.put("statements", statementsArray);
        return requestNode;

    }

    @Override
    protected ObjectNode executePost(HttpPost httpPost) {

        Objects.requireNonNull(httpPost);

        ObjectNode result = null;

        CloseableHttpResponse response = null;

        String entityString = null;
        try {
            response = httpclient.execute(httpPost);
            HttpEntity entity = response.getEntity();
            if (response.getStatusLine().getStatusCode() == 200
                    || response.getStatusLine().getStatusCode() == 201 && entity != null) {
                entityString = EntityUtils.toString(entity);
                result = mapper.readValue(entityString, ObjectNode.class);
            }
            LOGGER.debug("Writer response:\n{}\n{}\n{}", httpPost.toString(),
                    response.getStatusLine().getStatusCode(), entityString);
            if (result == null || (result.get("errors") != null && result.get("errors").isArray()
                    && result.get("errors").iterator().hasNext())) {
                LOGGER.error("Write Error: " + result.get("errors"));
            } else {
                LOGGER.debug("Write Success");
            }
        } catch (IOException ex) {
            LOGGER.error("IO error:\n{}\n{}\n{}", httpPost.toString(), response, ex.getMessage());
        } catch (Exception ex) {
            LOGGER.error("Write Exception:\n{}\n{}\n{}", httpPost.toString(), response, ex.getMessage());
        } finally {
            try {
                if (response != null) {
                    response.close();
                }
            } catch (IOException ignored) {
                LOGGER.trace("ignored IOException", ignored);
            }
        }
        return result;
    }

    @Override
    public void prepare(Object configurationObject) {

        super.prepare(null);
        mapper = StreamsJacksonMapper.getInstance();

        queryGraphHelper = new CypherQueryGraphHelper();
        httpGraphHelper = new Neo4jHttpGraphHelper();

        Objects.requireNonNull(queryGraphHelper);
        Objects.requireNonNull(httpGraphHelper);
    }

    @Override
    public void cleanUp() {

        LOGGER.info("exiting");

    }

}