Java tutorial
/* * 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.zeppelin.elasticsearch.client; import java.io.UnsupportedEncodingException; import java.net.URLEncoder; import java.util.Iterator; import java.util.Map; import java.util.Properties; import org.apache.commons.lang3.StringUtils; import org.apache.zeppelin.elasticsearch.ElasticsearchInterpreter; import org.apache.zeppelin.elasticsearch.action.ActionException; import org.apache.zeppelin.elasticsearch.action.ActionResponse; import org.apache.zeppelin.elasticsearch.action.AggWrapper; import org.apache.zeppelin.elasticsearch.action.AggWrapper.AggregationType; import org.apache.zeppelin.elasticsearch.action.HitWrapper; import org.json.JSONArray; import org.json.JSONObject; import com.google.common.base.Joiner; import com.google.gson.Gson; import com.google.gson.GsonBuilder; import com.google.gson.JsonParseException; import com.mashape.unirest.http.HttpResponse; import com.mashape.unirest.http.JsonNode; import com.mashape.unirest.http.Unirest; import com.mashape.unirest.http.exceptions.UnirestException; import com.mashape.unirest.request.HttpRequest; import com.mashape.unirest.request.HttpRequestWithBody; /** * Elasticsearch client using the HTTP API. */ public class HttpBasedClient implements ElasticsearchClient { private static final String QUERY_STRING_TEMPLATE = "{ \"query\": { \"query_string\": { \"query\": \"_Q_\", \"analyze_wildcard\": \"true\" } } }"; private final String host; private final int port; private final String username; private final String password; private final Gson gson = new GsonBuilder().setPrettyPrinting().create(); public HttpBasedClient(Properties props) { this.host = props.getProperty(ElasticsearchInterpreter.ELASTICSEARCH_HOST); this.port = Integer.parseInt(props.getProperty(ElasticsearchInterpreter.ELASTICSEARCH_PORT)); this.username = props.getProperty(ElasticsearchInterpreter.ELASTICSEARCH_BASIC_AUTH_USERNAME); this.password = props.getProperty(ElasticsearchInterpreter.ELASTICSEARCH_BASIC_AUTH_PASSWORD); } private boolean isSucceeded(HttpResponse response) { return response.getStatus() >= 200 && response.getStatus() < 300; } private JSONObject getParentField(JSONObject parent, String[] fields) { JSONObject obj = parent; for (int i = 0; i < fields.length - 1; i++) { obj = obj.getJSONObject(fields[i]); } return obj; } private JSONArray getFieldAsArray(JSONObject obj, String field) { final String[] fields = field.split("/"); final JSONObject parent = getParentField(obj, fields); return parent.getJSONArray(fields[fields.length - 1]); } private String getFieldAsString(HttpResponse<JsonNode> response, String field) { return getFieldAsString(response.getBody(), field); } private String getFieldAsString(JsonNode json, String field) { return json.getObject().get(field).toString(); } private long getFieldAsLong(HttpResponse<JsonNode> response, String field) { final String[] fields = field.split("/"); final JSONObject obj = getParentField(response.getBody().getObject(), fields); return obj.getLong(fields[fields.length - 1]); } private String getUrl(String index, String type, String id, boolean useSearch) { try { final StringBuilder buffer = new StringBuilder(); buffer.append("http://").append(host).append(":").append(port).append("/"); if (StringUtils.isNotEmpty(index)) { buffer.append(index); if (StringUtils.isNotEmpty(type)) { buffer.append("/").append(type); if (StringUtils.isNotEmpty(id)) { if (useSearch) { final String encodedId = URLEncoder.encode(id, "UTF-8"); if (id.equals(encodedId)) { // No difference, use directly the id buffer.append("/").append(id); } else { // There are differences: to avoid problems with some special characters // such as / and # in id, use a "terms" query buffer.append("/_search?source=").append(URLEncoder .encode("{\"query\":{\"terms\":{\"_id\":[\"" + id + "\"]}}}", "UTF-8")); } } else { buffer.append("/").append(id); } } } } return buffer.toString(); } catch (final UnsupportedEncodingException e) { throw new ActionException(e); } } private String getUrl(String[] indices, String[] types) { final String inds = indices == null ? null : Joiner.on(",").join(indices); final String typs = types == null ? null : Joiner.on(",").join(types); return getUrl(inds, typs, null, false); } @Override public ActionResponse get(String index, String type, String id) { ActionResponse response = null; try { final HttpRequest request = Unirest.get(getUrl(index, type, id, true)); if (StringUtils.isNotEmpty(username)) { request.basicAuth(username, password); } final HttpResponse<String> result = request.asString(); final boolean isSucceeded = isSucceeded(result); if (isSucceeded) { final JsonNode body = new JsonNode(result.getBody()); if (body.getObject().has("_index")) { response = new ActionResponse().succeeded(true) .hit(new HitWrapper(getFieldAsString(body, "_index"), getFieldAsString(body, "_type"), getFieldAsString(body, "_id"), getFieldAsString(body, "_source"))); } else { final JSONArray hits = getFieldAsArray(body.getObject(), "hits/hits"); final JSONObject hit = (JSONObject) hits.iterator().next(); response = new ActionResponse().succeeded(true).hit(new HitWrapper(hit.getString("_index"), hit.getString("_type"), hit.getString("_id"), hit.opt("_source").toString())); } } else { if (result.getStatus() == 404) { response = new ActionResponse().succeeded(false); } else { throw new ActionException(result.getBody()); } } } catch (final UnirestException e) { throw new ActionException(e); } return response; } @Override public ActionResponse delete(String index, String type, String id) { ActionResponse response = null; try { final HttpRequest request = Unirest.delete(getUrl(index, type, id, true)); if (StringUtils.isNotEmpty(username)) { request.basicAuth(username, password); } final HttpResponse<String> result = request.asString(); final boolean isSucceeded = isSucceeded(result); if (isSucceeded) { final JsonNode body = new JsonNode(result.getBody()); response = new ActionResponse().succeeded(true).hit(new HitWrapper(getFieldAsString(body, "_index"), getFieldAsString(body, "_type"), getFieldAsString(body, "_id"), null)); } else { throw new ActionException(result.getBody()); } } catch (final UnirestException e) { throw new ActionException(e); } return response; } @Override public ActionResponse index(String index, String type, String id, String data) { ActionResponse response = null; try { HttpRequestWithBody request = null; if (StringUtils.isEmpty(id)) { request = Unirest.post(getUrl(index, type, id, false)); } else { request = Unirest.put(getUrl(index, type, id, false)); } request.header("Accept", "application/json").header("Content-Type", "application/json").body(data) .getHttpRequest(); if (StringUtils.isNotEmpty(username)) { request.basicAuth(username, password); } final HttpResponse<JsonNode> result = request.asJson(); final boolean isSucceeded = isSucceeded(result); if (isSucceeded) { response = new ActionResponse().succeeded(true) .hit(new HitWrapper(getFieldAsString(result, "_index"), getFieldAsString(result, "_type"), getFieldAsString(result, "_id"), null)); } else { throw new ActionException(result.getBody().toString()); } } catch (final UnirestException e) { throw new ActionException(e); } return response; } @Override public ActionResponse search(String[] indices, String[] types, String query, int size) { ActionResponse response = null; if (!StringUtils.isEmpty(query)) { // The query can be either JSON-formatted, nor a Lucene query // So, try to parse as a JSON => if there is an error, consider the query a Lucene one try { gson.fromJson(query, Map.class); } catch (final JsonParseException e) { // This is not a JSON (or maybe not well formatted...) query = QUERY_STRING_TEMPLATE.replace("_Q_", query); } } try { final HttpRequestWithBody request = Unirest.post(getUrl(indices, types) + "/_search?size=" + size) .header("Content-Type", "application/json"); if (StringUtils.isNoneEmpty(query)) { request.header("Accept", "application/json").body(query); } if (StringUtils.isNotEmpty(username)) { request.basicAuth(username, password); } final HttpResponse<JsonNode> result = request.asJson(); final JSONObject body = result.getBody() != null ? result.getBody().getObject() : null; if (isSucceeded(result)) { final long total = getFieldAsLong(result, "hits/total"); response = new ActionResponse().succeeded(true).totalHits(total); if (containsAggs(result)) { JSONObject aggregationsMap = body.getJSONObject("aggregations"); if (aggregationsMap == null) { aggregationsMap = body.getJSONObject("aggs"); } for (final String key : aggregationsMap.keySet()) { final JSONObject aggResult = aggregationsMap.getJSONObject(key); if (aggResult.has("buckets")) { // Multi-bucket aggregations final Iterator<Object> buckets = aggResult.getJSONArray("buckets").iterator(); while (buckets.hasNext()) { response.addAggregation( new AggWrapper(AggregationType.MULTI_BUCKETS, buckets.next().toString())); } } else { response.addAggregation( new AggWrapper(AggregationType.SIMPLE, aggregationsMap.toString())); } break; // Keep only one aggregation } } else if (size > 0 && total > 0) { final JSONArray hits = getFieldAsArray(body, "hits/hits"); final Iterator<Object> iter = hits.iterator(); while (iter.hasNext()) { final JSONObject hit = (JSONObject) iter.next(); final Object data = hit.opt("_source") != null ? hit.opt("_source") : hit.opt("fields"); response.addHit(new HitWrapper(hit.getString("_index"), hit.getString("_type"), hit.getString("_id"), data.toString())); } } } else { throw new ActionException(body.get("error").toString()); } } catch (final UnirestException e) { throw new ActionException(e); } return response; } private boolean containsAggs(HttpResponse<JsonNode> result) { return result.getBody() != null && (result.getBody().getObject().has("aggregations") || result.getBody().getObject().has("aggs")); } @Override public void close() { } @Override public String toString() { return "HttpBasedClient [host=" + host + ", port=" + port + ", username=" + username + "]"; } }