Java tutorial
/* * Seldon -- open source prediction engine * ======================================= * * Copyright 2011-2015 Seldon Technologies Ltd and Rummble Ltd (http://www.seldon.io/) * * ******************************************************************************************** * * 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 * * 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 io.seldon.external; import io.seldon.api.Constants; import io.seldon.api.resource.ConsumerBean; import io.seldon.api.resource.service.ItemService; import io.seldon.clustering.recommender.ItemRecommendationAlgorithm; import io.seldon.clustering.recommender.ItemRecommendationResultSet; import io.seldon.clustering.recommender.RecommendationContext; import java.io.IOException; import java.net.URI; import java.net.URISyntaxException; import java.util.ArrayList; import java.util.List; import java.util.Map; import java.util.Set; import org.apache.commons.collections.CollectionUtils; import org.apache.commons.lang3.StringUtils; import org.apache.http.client.config.RequestConfig; import org.apache.http.client.methods.CloseableHttpResponse; import org.apache.http.client.methods.HttpGet; import org.apache.http.client.protocol.HttpClientContext; import org.apache.http.client.utils.URIBuilder; import org.apache.http.impl.client.CloseableHttpClient; import org.apache.http.impl.client.HttpClients; import org.apache.http.impl.conn.PoolingHttpClientConnectionManager; import org.apache.http.protocol.HttpContext; import org.apache.log4j.Logger; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Component; import com.fasterxml.jackson.databind.ObjectMapper; import com.fasterxml.jackson.databind.ObjectReader; /** * An Item Recommendation Algorithm that calls out to an HTTP endpoint for its recs. * * @author firemanphil * Date: 26/03/15 * Time: 12:15 */ @Component public class ExternalItemRecommendationAlgorithm implements ItemRecommendationAlgorithm { private static Logger logger = Logger.getLogger(ExternalItemRecommendationAlgorithm.class.getName()); private static final String URL_PROPERTY_NAME = "io.seldon.algorithm.external.url"; private static final String ALG_NAME_PROPERTY_NAME = "io.seldon.algorithm.external.name"; private final PoolingHttpClientConnectionManager cm; private final CloseableHttpClient httpClient; ObjectMapper mapper = new ObjectMapper(); private static final int DEFAULT_REQ_TIMEOUT = 200; private static final int DEFAULT_CON_TIMEOUT = 500; private static final int DEFAULT_SOCKET_TIMEOUT = 2000; ItemService itemService; @Autowired public ExternalItemRecommendationAlgorithm(ItemService itemService) { cm = new PoolingHttpClientConnectionManager(); cm.setMaxTotal(100); cm.setDefaultMaxPerRoute(20); RequestConfig requestConfig = RequestConfig.custom().setConnectionRequestTimeout(DEFAULT_REQ_TIMEOUT) .setConnectTimeout(DEFAULT_CON_TIMEOUT).setSocketTimeout(DEFAULT_SOCKET_TIMEOUT).build(); httpClient = HttpClients.custom().setConnectionManager(cm).setDefaultRequestConfig(requestConfig).build(); this.itemService = itemService; } @Override public ItemRecommendationResultSet recommend(String client, Long user, Set<Integer> dimensions, int maxRecsCount, RecommendationContext ctxt, List<Long> recentItemInteractions) { long timeNow = System.currentTimeMillis(); String recommenderName = ctxt.getOptsHolder().getStringOption(ALG_NAME_PROPERTY_NAME); String baseUrl = ctxt.getOptsHolder().getStringOption(URL_PROPERTY_NAME); if (ctxt.getInclusionKeys().isEmpty()) { logger.warn("Cannot get external recommendations are no includers were used. Returning 0 results"); return new ItemRecommendationResultSet(recommenderName); } URI uri = URI.create(baseUrl); try { URIBuilder builder = new URIBuilder().setScheme("http").setHost(uri.getHost()).setPort(uri.getPort()) .setPath(uri.getPath()).setParameter("client", client).setParameter("user_id", user.toString()) .setParameter("recent_interactions", StringUtils.join(recentItemInteractions, ",")) .setParameter("dimensions", StringUtils.join(dimensions, ",")) .setParameter("exclusion_items", StringUtils.join(ctxt.getExclusionItems(), ",")) .setParameter("data_key", StringUtils.join(ctxt.getInclusionKeys(), ",")) .setParameter("limit", String.valueOf(maxRecsCount)); if (ctxt.getCurrentItem() != null) builder.setParameter("item_id", ctxt.getCurrentItem().toString()); uri = builder.build(); } catch (URISyntaxException e) { logger.error("Couldn't create URI for external recommender with name " + recommenderName, e); return new ItemRecommendationResultSet(recommenderName); } HttpContext context = HttpClientContext.create(); HttpGet httpGet = new HttpGet(uri); try { if (logger.isDebugEnabled()) logger.debug("Requesting " + httpGet.getURI().toString()); CloseableHttpResponse resp = httpClient.execute(httpGet, context); try { if (resp.getStatusLine().getStatusCode() == 200) { ConsumerBean c = new ConsumerBean(client); ObjectReader reader = mapper.reader(AlgsResult.class); AlgsResult recs = reader.readValue(resp.getEntity().getContent()); List<ItemRecommendationResultSet.ItemRecommendationResult> results = new ArrayList<>( recs.recommended.size()); for (AlgResult rec : recs.recommended) { Map<String, Integer> attrDimsCandidate = itemService.getDimensionIdsForItem(c, rec.item); if (CollectionUtils.containsAny(dimensions, attrDimsCandidate.values()) || dimensions.contains(Constants.DEFAULT_DIMENSION)) { if (logger.isDebugEnabled()) logger.debug("Adding item " + rec.item); results.add( new ItemRecommendationResultSet.ItemRecommendationResult(rec.item, rec.score)); } else { if (logger.isDebugEnabled()) logger.debug("Rejecting item " + rec.item + " as not in dimensions " + dimensions); } } if (logger.isDebugEnabled()) logger.debug("External recommender took " + (System.currentTimeMillis() - timeNow) + "ms"); return new ItemRecommendationResultSet(results, recommenderName); } else { logger.error( "Couldn't retrieve recommendations from external recommender -- bad http return code: " + resp.getStatusLine().getStatusCode()); } } finally { if (resp != null) resp.close(); } } catch (IOException e) { logger.error("Couldn't retrieve recommendations from external recommender - ", e); } catch (Exception e) { logger.error("Couldn't retrieve recommendations from external recommender - ", e); } return new ItemRecommendationResultSet(recommenderName); } @Override public String name() { return null; } public static class AlgsResult { public List<AlgResult> recommended; } public static class AlgResult { public Long item; public Float score; } }