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.client.services; import io.seldon.client.algorithm.AlgorithmOptions; import io.seldon.client.beans.*; import io.seldon.client.constants.Constants; import io.seldon.client.exception.ApiTokenException; import io.seldon.client.exception.NoApiStateException; import java.net.SocketTimeoutException; import java.util.Calendar; import java.util.Map; import org.apache.log4j.Logger; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.http.*; import org.springframework.http.client.CommonsClientHttpRequestFactory; import org.springframework.web.client.HttpClientErrorException; import org.springframework.web.client.ResourceAccessException; import org.springframework.web.client.RestClientException; import org.springframework.web.client.RestTemplate; public class ApiServiceImpl implements ApiService { public static final int DEFAULT_READ_TIMEOUT = 1500; private int readTimeout = DEFAULT_READ_TIMEOUT; @Autowired private ApiState apiState; private static Logger logger = Logger.getLogger(ApiServiceImpl.class.getName()); private String token = null; private long tokenExpiry; private TokenBean tokenBean; public void setApiState(ApiState apiState) { this.apiState = apiState; if (apiState.getReadTimeout() != null) { readTimeout = apiState.getReadTimeout(); } } public synchronized ResourceBean getToken() { Calendar calendar = Calendar.getInstance(); long timeInMillis = calendar.getTimeInMillis(); logger.debug(" Time in millis: " + timeInMillis); logger.debug("Token expires at: " + tokenExpiry); if (timeInMillis < tokenExpiry) { logger.debug("(Another thread has already refreshed the token)"); return tokenBean; } if (apiState == null) { throw new NoApiStateException("Please set your API key and secret before using the API."); } StringBuilder stringBuilder = new StringBuilder(); logger.info("* Fetching token..."); stringBuilder.append(getApiRoot(true)); // attempt to use a secure connection (or fall back on apiUrl) stringBuilder.append("/token?"); stringBuilder.append("consumer_key="); stringBuilder.append(apiState.getConsumerKey()); stringBuilder.append("&"); stringBuilder.append("consumer_secret="); stringBuilder.append(apiState.getConsumerSecret()); ResourceBean res; try { res = getTokenResource(stringBuilder.toString()); } catch (HttpClientErrorException e) { throw new ApiTokenException("Could not retrieve token -- please check your key and secret."); } if (res instanceof TokenBean) { TokenBean tokenBean = (TokenBean) res; this.tokenBean = tokenBean; timeInMillis = calendar.getTimeInMillis(); this.tokenExpiry = timeInMillis + tokenBean.getExpires_in(); this.token = tokenBean.getAccess_token(); } return res; } private String getApiRoot(boolean withSecureConnection) { String apiRoot; if (withSecureConnection) { logger.info("** Trying secure connection..."); apiRoot = apiState.getSecureApiUrl(); if (apiRoot != null && apiRoot.length() > 0) { logger.info("*** OK"); return apiRoot; } logger.info("*** NOK"); } apiRoot = apiState.getApiUrl(); return apiRoot; } @Override public ResourceBean getItems(int limit, boolean full, String keyword, String name) { String res = Constants.ITEMS; String url = getUrl(res, limit, full, keyword, name); return getResource(url, ItemsBean.class); } @Override public ResourceBean getItems(int limit, Integer itemType, boolean full, String sorting) { String res = Constants.ITEMS; String url = getUrl(res, limit, full, null) + "&sort=" + sorting + "&type=" + itemType; return getResource(url, ItemsBean.class); } @Override public ResourceBean getItems(int limit, Integer itemType, boolean full, String keyword, String name) { String res = Constants.ITEMS; String url = getUrl(res, limit, full, keyword, name) + "&type=" + itemType; return getResource(url, ItemsBean.class); } @SuppressWarnings({ "NullableProblems" }) public ResourceBean getItems(int limit, boolean full) { String res = Constants.ITEMS; String url = getUrl(res, limit, full, null); return getResource(url, ItemsBean.class); } @SuppressWarnings({ "NullableProblems" }) @Override public ResourceBean getItems(int limit, int type, boolean full) { String res = Constants.ITEMS; String url = getUrl(res, limit, full, null) + "&type=" + type; return getResource(url, ItemsBean.class); } @SuppressWarnings({ "NullableProblems" }) @Override public ResourceBean getItems(int limit, boolean full, String sorting) { String res = Constants.ITEMS; String url = getUrl(res, limit, full, null) + "&sort=" + sorting; return getResource(url, ItemsBean.class); } public ResourceBean getItem(String id, boolean full) { String res = Constants.ITEMS + "/" + id; String url = getUrl(res, full); return getResource(url, ItemBean.class); } public ResourceBean getUsers(int limit, boolean full) { return getUsers(limit, full, false); } @SuppressWarnings({ "NullableProblems" }) @Override public ResourceBean getUsers(int limit, boolean full, boolean withSecureConnection) { String res = Constants.USERS; String apiRoot = getApiRoot(withSecureConnection); String url = getUrl(apiRoot, res, limit, full, null); return getResource(url, UsersBean.class); } public ResourceBean getUser(String id, boolean full) { return getUser(id, full, false); } @Override public ResourceBean getUser(String id, boolean full, boolean withSecureConnection) { String res = Constants.USERS + "/" + id; String apiRoot = getApiRoot(withSecureConnection); String url = getUrl(apiRoot, res, full); return getResource(url, UserBean.class); } public ResourceBean getSimilarItems(String id, int limit) { String res = Constants.ITEMS + "/" + id + "/" + Constants.SIMILARITYGRAPH; String url = getUrl(res); return getResource(url, ItemGraphBean.class); } @SuppressWarnings({ "NullableProblems" }) public ResourceBean getTrustedUsers(String id, int limit) { String res = Constants.USERS + "/" + id + "/" + Constants.TRUSTGRAPH; String url = getUrl(res, limit, false, null); return getResource(url, UserGraphBean.class); } public ResourceBean getPrediction(String uid, String oid) { String res = Constants.USERS + "/" + uid + "/" + Constants.OPINIONS + "/" + oid; String url = getUrl(res); return getResource(url, OpinionBean.class); } public ResourceBean getOpinions(String uid, int limit) { String res = Constants.USERS + "/" + uid + "/" + Constants.OPINIONS; String url = getUrl(res, limit, true, ""); return getResource(url, OpinionsBean.class); } public ResourceBean getItemOpinions(String itemId, int limit) { String res = Constants.ITEMS + "/" + itemId + "/" + Constants.OPINIONS; String url = getUrl(res, limit, true, ""); return getResource(url, OpinionsBean.class); } public ResourceBean getRecommendations(String uid, String keyword, Integer dimension, int limit, AlgorithmOptions algorithmOptions) { String res = Constants.USERS + "/" + uid + "/" + Constants.RECOMMENDATIONS; String url = getUrl(res, limit, false, keyword); if (dimension != null) { url += "&dimension=" + dimension; } if (algorithmOptions != null) { String aoString; aoString = algorithmOptions.toString(); if (aoString.length() > 0) { url += "&algorithms=" + aoString; } } return getResource(url, RecommendationsBean.class); } public ResourceBean getRecommendations(String uid) { String res = Constants.USERS + "/" + uid + "/" + Constants.RECOMMENDATIONS; String url = getUrl(res); return getResource(url, RecommendationsBean.class); } public ResourceBean getRecommendedUsers(String userId, String itemId) { return getRecommendedUsers(userId, itemId, null); } public ResourceBean getRecommendedUsers(String userId, String itemId, String linkType) { String res = Constants.USERS + "/" + userId + "/recommendations/" + itemId + "/trustgraph"; String url = getUrl(res); if (linkType != null) { url += "linktype=" + linkType; } return getResource(url, RecommendedUsersBean.class); } public ResourceBean getDimensions() { String res = Constants.DIMENSIONS; String url = getUrl(res); return getResource(url, DimensionsBean.class); } public ResourceBean getDimensionById(String dimensionId) { String res = Constants.DIMENSIONS + "/" + dimensionId; String url = getUrl(res); return getResource(url, DimensionBean.class); } public ResourceBean getUserActions(String uid, int limit) { String res = Constants.USERS + "/" + uid + "/" + Constants.ACTIONS; String url = getUrl(res, limit, true, ""); return getResource(url, ActionsBean.class); } public ResourceBean getActions() { String res = Constants.ACTIONS; String url = getUrl(res); return getResource(url, ActionsBean.class); } public ResourceBean getActionById(String actionId) { String res = Constants.ACTIONS + "/" + actionId; String url = getUrl(res); return getResource(url, ActionBean.class); } @SuppressWarnings({ "NullableProblems" }) @Override public ResourceBean getRecommendedUsers(String userId, String itemId, Long linkType, String keywords, Integer limit) { String res = Constants.USERS + "/" + userId + "/" + Constants.RECOMMENDATIONS + "/" + itemId + "/" + Constants.TRUSTGRAPH; String url = getUrl(res, limit, null, keywords); if (linkType != null) { url += "&linktype=" + linkType; } return getResource(url, RecommendedUsersBean.class); } @Override public ResourceBean getItemTypes() { String res = Constants.ITEMS + "/" + Constants.TYPES; String url = getUrl(res); return getResource(url, ItemTypesBean.class); } @Override public ResourceBean getActionTypes() { String res = Constants.ACTIONS + "/" + Constants.TYPES; String url = getUrl(res); return getResource(url, ActionTypesBean.class); } @Override public ResourceBean getRecommendationByItemType(String uid, int itemType, int limit) { String res = Constants.USERS + "/" + uid + "/" + Constants.RECOMMENDATIONS; String url = getUrl(res) + "type=" + itemType + "&limit=" + limit; return getResource(url, RecommendationsBean.class); } @Override public ResourceBean getUsersMatchingUsername(String username) { String url = getUrl(Constants.USERS) + "name=" + username; return getResource(url, UsersBean.class); } // ~~ Post methods ~~ public Object addAction(ActionBean actionBean) { String url = getUrl(Constants.ACTIONS); return performPost(url, actionBean); } public Object addItem(ItemBean itemBean) { String url = getUrl(Constants.ITEMS); return performPost(url, itemBean); } @Override public Object updateItem(ItemBean itemBean) { String url = getUrl(Constants.ITEMS); return performPut(url, itemBean); } @Override public Object updateUser(UserBean userBean) { return updateUser(userBean, false); } @Override public Object updateUser(UserBean userBean, boolean withSecureConnection) { String apiRoot = getApiRoot(withSecureConnection); String url = getUrl(apiRoot, Constants.USERS); return performPut(url, userBean); } @Override public Object updateAction(ActionBean actionBean) { String url = getUrl(Constants.ACTIONS); return performPut(url, actionBean); } @Override public Object addUser(UserBean userBean) { return addUser(userBean, false); } @Override public Object addUser(UserBean userBean, boolean withSecureConnection) { String apiRoot = getApiRoot(withSecureConnection); String url = getUrl(apiRoot, Constants.USERS); return performPost(url, userBean); } @SuppressWarnings({ "NullableProblems" }) @Override public ResourceBean getRankedItems(String uid, RecommendationsBean recs, Integer limit) { return getRankedItems(uid, recs, limit, null); } @SuppressWarnings({ "NullableProblems" }) @Override public ResourceBean getRankedItems(String uid, RecommendationsBean recs, Integer limit, AlgorithmOptions algorithmOptions) { String res = Constants.USERS + "/" + uid + "/" + Constants.RECOMMENDATIONS; String url = getUrl(res, limit, null, null); if (algorithmOptions != null) { String aoString; aoString = algorithmOptions.toString(); if (aoString.length() > 0) { url += "&algorithms=" + aoString; } } return performPostGet(url, recs, recs.getClass()); } private String getUrl(String resource, Integer limit, Boolean full, String keyword) { return getUrl(apiState.getApiUrl(), resource, limit, full, keyword); } private String getUrl(String baseUrl, String resource, Integer limit, Boolean full, String keyword) { String url = baseUrl + "/" + resource + "?"; if (full != null) { url += "full=" + full; } if (limit != null && limit != Constants.NO_LIMIT) { url += "&limit=" + limit; } if (keyword != null) { url += "&keyword=" + keyword; } return url; } private String getUrl(String resource, int limit, boolean full, String keyword, String name) { String url = getUrl(resource, limit, full, keyword); if (name != null) { url += ("&name=" + name); } return url; } private String getUrl(String resource) { return apiState.getApiUrl() + "/" + resource + "?"; } private String getUrl(String apiRoot, String resource) { return apiRoot + "/" + resource + "?"; } private String getUrl(String apiRoot, String resource, boolean full) { return apiRoot + "/" + resource + "?full=" + full; } private String getUrl(String resource, boolean full) { return apiState.getApiUrl() + "/" + resource + "?full=" + full; } private ResourceBean getResource(final String url, Class<?> c) { logger.info("* GET Endpoint: " + url); ResourceBean bean; if (token == null) { ResourceBean r = getToken(); if (r instanceof ErrorBean) return r; } String urlWithToken = url + "&oauth_token=" + token; logger.debug("** Token: " + token); logger.debug("** Class: " + c.getName()); HttpHeaders headers = new HttpHeaders(); headers.setContentType(MediaType.APPLICATION_JSON); HttpEntity<String> entity = new HttpEntity<String>(headers); RestTemplate restTemplate = createRestTemplate(); try { //logger.info("Calling end point: " + urlWithToken + " for class: " + c.getName()); @SuppressWarnings("unchecked") HttpEntity<ResourceBean> res = (HttpEntity<ResourceBean>) restTemplate.exchange(urlWithToken, HttpMethod.GET, entity, c); logger.debug("Result: " + res.toString() + " : " + res.getBody()); bean = res.getBody(); logger.debug("*** OK (" + urlWithToken + ")"); } catch (Exception e) { if (e.getCause() instanceof SocketTimeoutException) { return createTimeoutBean(); } logger.error("Exception class: " + e.getClass()); //logger.error("Failed Api Call for url: " + urlWithToken + " : " + e.toString()); logger.error("*** NOK (" + urlWithToken + "): " + e.getMessage()); HttpEntity<ErrorBean> res = null; try { res = restTemplate.exchange(urlWithToken, HttpMethod.GET, entity, ErrorBean.class); } catch (RestClientException e1) { if (e1.getCause() instanceof SocketTimeoutException) { return createTimeoutBean(); } } bean = res.getBody(); } if (bean instanceof ErrorBean) { if (((ErrorBean) bean).getError_id() != Constants.TOKEN_EXPIRED) { return bean; } else { logger.info("Token expired; fetching a new one."); ResourceBean r = getToken(); if (r instanceof ErrorBean) { return r; } else { return getResource(url, c); } } } else { return bean; } } /** * Use this method to create rest templates -- don't instantiate them directly. * * @return a Spring {@link RestTemplate} with the appropriate read timeout. */ private RestTemplate createRestTemplate() { RestTemplate restTemplate; final CommonsClientHttpRequestFactory requestFactory = new CommonsClientHttpRequestFactory(); requestFactory.setReadTimeout(readTimeout); restTemplate = new RestTemplate(requestFactory); return restTemplate; } private Object performPost(final String endpointUrl, ResourceBean resourceBean) { logger.info("* POST Endpoint: " + endpointUrl); if (token == null) { ResourceBean r = getToken(); if (r instanceof ErrorBean) return r; } String url = endpointUrl + "&oauth_token=" + token; RestTemplate template = createRestTemplate(); logger.debug("* Posting: " + resourceBean); logger.debug("** Endpoint: " + url); // API return types for posts vary: Map on success, ErrorBean on failure -- we're forced to use Object here: ResponseEntity<Object> responseEntity = null; try { responseEntity = template.postForEntity(url, resourceBean, Object.class); } catch (ResourceAccessException e) { if (e.getCause() instanceof SocketTimeoutException) { return createTimeoutBean(); } } Object body = responseEntity.getBody(); logger.debug("** Response: " + body); if (body instanceof Map) { @SuppressWarnings("unchecked") Map<String, Object> map = (Map<String, Object>) body; String response = (String) map.get("response"); String errorMessage = (String) map.get("error_msg"); // if this is an error bean if (response == null && errorMessage != null) { response = errorMessage; } if (response != null) { // not great; some posts return response maps, some return resource beans if (!response.equals("ok")) { if (response.equals("Token expired")) { logger.debug("Token expired; acquiring a fresh one..."); ResourceBean r = getToken(); if (r instanceof ErrorBean) return r; return performPost(endpointUrl, resourceBean); } else { return new ErrorBean(map); } } } } return body; } private ErrorBean createTimeoutBean() { ErrorBean timeoutBean = new ErrorBean(); timeoutBean.setError_msg("ApiService socket timeout."); return timeoutBean; } private Object performPut(final String endpointUrl, ResourceBean resourceBean) { logger.info("* PUT Endpoint: " + endpointUrl); if (token == null) { ResourceBean r = getToken(); if (r instanceof ErrorBean) return r; } String url = endpointUrl + "&oauth_token=" + token; RestTemplate template = createRestTemplate(); logger.debug("* PUTting: " + resourceBean); logger.debug("** Endpoint: " + url); // API return types for posts vary: Map on success, ErrorBean on failure -- we're forced to use Object here: //template.put(url, resourceBean); HttpEntity<ResourceBean> entity = new HttpEntity<ResourceBean>(resourceBean); ResponseEntity<Object> responseEntity = null; try { responseEntity = template.exchange(url, HttpMethod.PUT, entity, Object.class); } catch (ResourceAccessException e) { if (e.getCause() instanceof SocketTimeoutException) { return createTimeoutBean(); } } Object body = responseEntity.getBody(); logger.debug("PUT response: " + body); if (body instanceof Map) { @SuppressWarnings("unchecked") Map<String, Object> map = (Map<String, Object>) body; String response = (String) map.get("response"); String errorMessage = (String) map.get("error_msg"); // if this is an error bean if (response == null && errorMessage != null) { response = errorMessage; } if (response != null) { // not great; some posts return response maps, some return resource beans if (!response.equals("ok")) { if (response.equals("Token expired")) { logger.debug("Token expired; acquiring a fresh one..."); ResourceBean r = getToken(); if (r instanceof ErrorBean) return r; return performPut(endpointUrl, resourceBean); } else { return new ErrorBean(map); } } } } return body; } private ResourceBean performPostGet(final String endpointUrl, final ResourceBean resourceBean, Class c) { ResourceBean bean; if (token == null) { ResourceBean r = getToken(); if (r instanceof ErrorBean) return r; } String url = endpointUrl + "&oauth_token=" + token; //header HttpHeaders headers = new HttpHeaders(); headers.setContentType(MediaType.APPLICATION_JSON); HttpEntity<ResourceBean> entity = new HttpEntity<ResourceBean>(resourceBean, headers); RestTemplate template = createRestTemplate(); try { logger.debug("* Posting: " + resourceBean); logger.debug("** Endpoint: " + url); // API return types for posts vary: Map on success, ErrorBean on failure -- we're forced to use Object here: ResponseEntity<ResourceBean> responseEntity; responseEntity = template.postForEntity(url, entity, c); bean = responseEntity.getBody(); } catch (Exception e) { if (e.getCause() instanceof SocketTimeoutException) { return createTimeoutBean(); } logger.error("Exception class: " + e.getClass()); //logger.error("Failed Api Call for url: " + urlWithToken + " : " + e.toString()); logger.error("*** NOK (" + url + "): " + e.getMessage()); HttpEntity<ErrorBean> res; try { res = template.postForEntity(url, entity, ErrorBean.class); } catch (ResourceAccessException rae) { return createTimeoutBean(); } bean = res.getBody(); } if (bean instanceof ErrorBean) { if (((ErrorBean) bean).getError_id() != Constants.TOKEN_EXPIRED) { return bean; } else { logger.info("Token expired; fetching a new one."); ResourceBean r = getToken(); if (r instanceof ErrorBean) { return r; } else { return performPostGet(endpointUrl, resourceBean, c); } } } else { return bean; } } private ResourceBean getTokenResource(String url) { ResourceBean bean; HttpHeaders headers = new HttpHeaders(); headers.setContentType(MediaType.APPLICATION_JSON); HttpEntity<String> entity = new HttpEntity<String>(headers); try { ResponseEntity<TokenBean> res = new RestTemplate().exchange(url, HttpMethod.GET, entity, TokenBean.class); bean = res.getBody(); } catch (Exception e) { HttpEntity<ErrorBean> res = new RestTemplate().exchange(url, HttpMethod.GET, entity, ErrorBean.class); bean = res.getBody(); } return bean; } }