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From: steveblackmon <git@git.apache.org>
To: dev@streams.incubator.apache.org
Reply-To: dev@streams.incubator.apache.org
References: <git-pr-203-incubator-streams@git.apache.org>
In-Reply-To: <git-pr-203-incubator-streams@git.apache.org>
Subject: [GitHub] incubator-streams pull request: STREAMS-231
Content-Type: text/plain
Message-Id: <20150401142548.47267E05DF@git1-us-west.apache.org>
Date: Wed,  1 Apr 2015 14:25:48 +0000 (UTC)

Github user steveblackmon commented on a diff in the pull request:

    https://github.com/apache/incubator-streams/pull/203#discussion_r27573266
  
    --- Diff: streams-components/streams-http/src/main/java/org/apache/streams/components/http/provider/SimpleHttpProvider.java ---
    @@ -0,0 +1,324 @@
    +/*
    + * 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.components.http.provider;
    +
    +import com.fasterxml.jackson.databind.JsonNode;
    +import com.fasterxml.jackson.databind.ObjectMapper;
    +import com.fasterxml.jackson.databind.node.ArrayNode;
    +import com.fasterxml.jackson.databind.node.ObjectNode;
    +import com.google.common.base.Joiner;
    +import com.google.common.base.Preconditions;
    +import com.google.common.collect.Maps;
    +import com.google.common.util.concurrent.Uninterruptibles;
    +import org.apache.commons.lang.NotImplementedException;
    +import org.apache.http.HttpEntity;
    +import org.apache.http.client.methods.CloseableHttpResponse;
    +import org.apache.http.client.methods.HttpGet;
    +import org.apache.http.client.methods.HttpPost;
    +import org.apache.http.client.methods.HttpRequestBase;
    +import org.apache.http.client.utils.URIBuilder;
    +import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
    +import org.apache.http.conn.ssl.SSLContextBuilder;
    +import org.apache.http.conn.ssl.TrustSelfSignedStrategy;
    +import org.apache.http.impl.client.CloseableHttpClient;
    +import org.apache.http.impl.client.HttpClients;
    +import org.apache.http.util.EntityUtils;
    +import org.apache.streams.components.http.HttpConfigurator;
    +import org.apache.streams.components.http.HttpProviderConfiguration;
    +import org.apache.streams.config.StreamsConfigurator;
    +import org.apache.streams.core.StreamsDatum;
    +import org.apache.streams.core.StreamsProvider;
    +import org.apache.streams.core.StreamsResultSet;
    +import org.apache.streams.jackson.StreamsJacksonMapper;
    +import org.joda.time.DateTime;
    +import org.slf4j.Logger;
    +import org.slf4j.LoggerFactory;
    +
    +import java.io.IOException;
    +import java.math.BigInteger;
    +import java.net.URI;
    +import java.net.URISyntaxException;
    +import java.security.KeyManagementException;
    +import java.security.KeyStoreException;
    +import java.security.NoSuchAlgorithmException;
    +import java.util.ArrayList;
    +import java.util.Collection;
    +import java.util.Iterator;
    +import java.util.List;
    +import java.util.Map;
    +import java.util.Queue;
    +import java.util.concurrent.Callable;
    +import java.util.concurrent.ConcurrentLinkedQueue;
    +import java.util.concurrent.ExecutionException;
    +import java.util.concurrent.ExecutorService;
    +import java.util.concurrent.Executors;
    +import java.util.concurrent.Future;
    +import java.util.concurrent.TimeUnit;
    +import java.util.concurrent.TimeoutException;
    +import java.util.concurrent.locks.ReadWriteLock;
    +import java.util.concurrent.locks.ReentrantReadWriteLock;
    +
    +/**
    + * Provider retrieves contents from an known set of urls and passes all resulting objects downstream
    + */
    +public class SimpleHttpProvider implements StreamsProvider {
    +
    +    private final static String STREAMS_ID = "SimpleHttpProvider";
    +
    +    private final static Logger LOGGER = LoggerFactory.getLogger(SimpleHttpProvider.class);
    +
    +    protected ObjectMapper mapper;
    +
    +    protected URIBuilder uriBuilder;
    +
    +    protected CloseableHttpClient httpclient;
    +
    +    protected HttpProviderConfiguration configuration;
    +
    +    protected volatile Queue<StreamsDatum> providerQueue = new ConcurrentLinkedQueue<StreamsDatum>();
    +
    +    protected final ReadWriteLock lock = new ReentrantReadWriteLock();
    +
    +    private ExecutorService executor;
    +
    +    public SimpleHttpProvider() {
    +        this(HttpConfigurator.detectProviderConfiguration(StreamsConfigurator.config.getConfig("http")));
    +    }
    +
    +    public SimpleHttpProvider(HttpProviderConfiguration providerConfiguration) {
    +        LOGGER.info("creating SimpleHttpProvider");
    +        LOGGER.info(providerConfiguration.toString());
    +        this.configuration = providerConfiguration;
    +    }
    +
    +    /**
    +      Override this to add parameters to the request
    +     */
    +    protected Map<String, String> prepareParams(StreamsDatum entry) {
    +
    +        return Maps.newHashMap();
    +    }
    +
    +    public HttpRequestBase prepareHttpRequest(URI uri) {
    +        HttpRequestBase request;
    +        if( configuration.getRequestMethod().equals(HttpProviderConfiguration.RequestMethod.GET)) {
    +            request = new HttpGet(uri);
    +        } else if( configuration.getRequestMethod().equals(HttpProviderConfiguration.RequestMethod.POST)) {
    +            request = new HttpPost(uri);
    +        } else {
    +            // this shouldn't happen because of the default
    +            request = new HttpGet(uri);
    +        }
    +
    +        request.addHeader("content-type", this.configuration.getContentType());
    +
    +        return request;
    +
    +    }
    +
    +    @Override
    +    public void prepare(Object configurationObject) {
    +
    +        mapper = StreamsJacksonMapper.getInstance();
    +
    +        uriBuilder = new URIBuilder()
    +            .setScheme(this.configuration.getProtocol())
    +            .setHost(this.configuration.getHostname())
    +            .setPort(this.configuration.getPort().intValue())
    +            .setPath(this.configuration.getResourcePath());
    +
    +        SSLContextBuilder builder = new SSLContextBuilder();
    +        SSLConnectionSocketFactory sslsf = null;
    +        try {
    +            builder.loadTrustMaterial(null, new TrustSelfSignedStrategy());
    +            sslsf = new SSLConnectionSocketFactory(
    +                    builder.build(), SSLConnectionSocketFactory.ALLOW_ALL_HOSTNAME_VERIFIER);
    +        } catch (NoSuchAlgorithmException e) {
    +            LOGGER.warn(e.getMessage());
    +        } catch (KeyManagementException e) {
    +            LOGGER.warn(e.getMessage());
    +        } catch (KeyStoreException e) {
    +            LOGGER.warn(e.getMessage());
    +        }
    +
    +        httpclient = HttpClients.custom().setSSLSocketFactory(
    +                sslsf).build();
    +
    +        executor = Executors.newSingleThreadExecutor();
    +
    +    }
    +
    +    @Override
    +    public void cleanUp() {
    +
    +        LOGGER.info("shutting down SimpleHttpProvider");
    +        this.shutdownAndAwaitTermination(executor);
    +        try {
    +            httpclient.close();
    +        } catch (IOException e) {
    +            e.printStackTrace();
    +        } finally {
    +            try {
    +                httpclient.close();
    +            } catch (IOException e) {
    +                e.printStackTrace();
    +            } finally {
    +                httpclient = null;
    +            }
    +        }
    +    }
    +
    +    @Override
    +    public void startStream() {
    +
    +        executor.execute(new Runnable() {
    +            @Override
    +            public void run() {
    +
    +                readCurrent();
    +
    +                Uninterruptibles.sleepUninterruptibly(5, TimeUnit.SECONDS);
    +
    +            }
    +        });
    +    }
    +
    +    @Override
    +    public StreamsResultSet readCurrent() {
    +        StreamsResultSet current;
    +
    +        uriBuilder = uriBuilder.setPath(
    +            Joiner.on("/").skipNulls().join(uriBuilder.getPath(), configuration.getResource(), configuration.getResourcePostfix())
    +        );
    +
    +        URI uri;
    +        try {
    +            uri = uriBuilder.build();
    +        } catch (URISyntaxException e) {
    +            uri = null;
    +        }
    +
    +        List<ObjectNode> results = execute(uri);
    +
    +        lock.writeLock().lock();
    +
    +        for( ObjectNode item : results ) {
    +            providerQueue.add(newDatum(item));
    +        }
    +
    +        LOGGER.debug("Creating new result set for {} items", providerQueue.size());
    +        current = new StreamsResultSet(providerQueue);
    +
    +        return current;
    +    }
    +
    +    protected List<ObjectNode> execute(URI uri) {
    +
    +        Preconditions.checkNotNull(uri);
    +
    +        List<ObjectNode> results = new ArrayList<>();
    +
    +        HttpRequestBase httpRequest = prepareHttpRequest(uri);
    +
    +        CloseableHttpResponse response = null;
    +
    +        String entityString = null;
    +        try {
    +            response = httpclient.execute(httpRequest);
    +            HttpEntity entity = response.getEntity();
    +            // TODO: handle retry
    +            if (response.getStatusLine().getStatusCode() == 200 && entity != null) {
    +                entityString = EntityUtils.toString(entity);
    +                if( !entityString.equals("{}") && !entityString.equals("[]") ) {
    +                    JsonNode jsonNode = mapper.readValue(entityString, JsonNode.class);
    +                    results = parse(jsonNode);
    +                }
    +            }
    +        } catch (IOException e) {
    +            LOGGER.error("IO error:\n{}\n{}\n{}", uri.toString(), response, e.getMessage());
    +        } finally {
    +            try {
    +                response.close();
    +            } catch (IOException e) {}
    +        }
    +        return results;
    +    }
    +
    +    /**
    +     Override this to change how entity gets converted to objects
    +     */
    +    protected List<ObjectNode> parse(JsonNode jsonNode) {
    +
    +        List<ObjectNode> results = new ArrayList<>();
    +
    +        if (jsonNode != null && jsonNode instanceof ObjectNode ) {
    +            results.add((ObjectNode) jsonNode);
    +        } else if (jsonNode != null && jsonNode instanceof ArrayNode) {
    +            ArrayNode arrayNode = (ArrayNode) jsonNode;
    +            Iterator<JsonNode> iterator = arrayNode.elements();
    +            while (iterator.hasNext()) {
    +                ObjectNode element = (ObjectNode) iterator.next();
    +
    +                results.add(element);
    +            }
    +        }
    +
    +        return results;
    +    }
    +
    +    /**
    +     Override this to change how metadata is derived from object
    +     */
    +    protected StreamsDatum newDatum(ObjectNode item) {
    +        return new StreamsDatum(item, item.get("id").asText(), new DateTime(item.get("timestamp").asText()));
    --- End diff --
    
    I agree.  pushing an improved version of this method.


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