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.kylin; import org.apache.commons.codec.binary.Base64; import org.apache.http.HttpResponse; import org.apache.http.client.HttpClient; import org.apache.http.client.methods.HttpPost; import org.apache.http.entity.StringEntity; import org.apache.http.impl.client.HttpClientBuilder; import org.apache.zeppelin.interpreter.Interpreter; import org.apache.zeppelin.interpreter.InterpreterContext; import org.apache.zeppelin.interpreter.InterpreterPropertyBuilder; import org.apache.zeppelin.interpreter.InterpreterResult; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.util.List; import java.util.Properties; import java.util.regex.Matcher; import java.util.regex.Pattern; /** * Kylin interpreter for Zeppelin. (http://kylin.io) */ public class KylinInterpreter extends Interpreter { Logger logger = LoggerFactory.getLogger(KylinInterpreter.class); static final String KYLIN_QUERY_API_URL = "kylin.api.url"; static final String KYLIN_USERNAME = "kylin.api.user"; static final String KYLIN_PASSWORD = "kylin.api.password"; static final String KYLIN_QUERY_PROJECT = "kylin.query.project"; static final String KYLIN_QUERY_OFFSET = "kylin.query.offset"; static final String KYLIN_QUERY_LIMIT = "kylin.query.limit"; static final String KYLIN_QUERY_ACCEPT_PARTIAL = "kylin.query.ispartial"; static final Pattern KYLIN_TABLE_FORMAT_REGEX_LABEL = Pattern.compile("\"label\":\"(.*?)\""); static final Pattern KYLIN_TABLE_FORMAT_REGEX = Pattern.compile("\"results\":\\[\\[\"(.*?)\"]]"); static { Interpreter.register("kylin", "kylin", KylinInterpreter.class.getName(), new InterpreterPropertyBuilder().add(KYLIN_USERNAME, "ADMIN", "username for kylin user") .add(KYLIN_PASSWORD, "KYLIN", "password for kylin user") .add(KYLIN_QUERY_API_URL, "http://<host>:<port>/kylin/api/query", "Kylin API.") .add(KYLIN_QUERY_PROJECT, "default", "kylin project name") .add(KYLIN_QUERY_OFFSET, "0", "kylin query offset") .add(KYLIN_QUERY_LIMIT, "5000", "kylin query limit") .add(KYLIN_QUERY_ACCEPT_PARTIAL, "true", "The kylin query partial flag").build()); } public KylinInterpreter(Properties property) { super(property); } @Override public void open() { } @Override public void close() { } @Override public InterpreterResult interpret(String st, InterpreterContext context) { try { return executeQuery(st); } catch (IOException e) { logger.error("failed to query data in kylin ", e); return new InterpreterResult(InterpreterResult.Code.ERROR, e.getMessage()); } } @Override public void cancel(InterpreterContext context) { } @Override public FormType getFormType() { return FormType.SIMPLE; } @Override public int getProgress(InterpreterContext context) { return 0; } @Override public List<String> completion(String buf, int cursor) { return null; } public HttpResponse prepareRequest(String sql) throws IOException { String KYLIN_PROJECT = getProperty(KYLIN_QUERY_PROJECT); logger.info("project:" + KYLIN_PROJECT); logger.info("sql:" + sql); logger.info("acceptPartial:" + getProperty(KYLIN_QUERY_ACCEPT_PARTIAL)); logger.info("limit:" + getProperty(KYLIN_QUERY_LIMIT)); logger.info("offset:" + getProperty(KYLIN_QUERY_OFFSET)); byte[] encodeBytes = Base64.encodeBase64( new String(getProperty(KYLIN_USERNAME) + ":" + getProperty(KYLIN_PASSWORD)).getBytes("UTF-8")); String postContent = new String("{\"project\":" + "\"" + KYLIN_PROJECT + "\"" + "," + "\"sql\":" + "\"" + sql + "\"" + "," + "\"acceptPartial\":" + "\"" + getProperty(KYLIN_QUERY_ACCEPT_PARTIAL) + "\"" + "," + "\"offset\":" + "\"" + getProperty(KYLIN_QUERY_OFFSET) + "\"" + "," + "\"limit\":" + "\"" + getProperty(KYLIN_QUERY_LIMIT) + "\"" + "}"); logger.info("post:" + postContent); postContent = postContent.replaceAll("[\u0000-\u001f]", " "); StringEntity entity = new StringEntity(postContent, "UTF-8"); entity.setContentType("application/json; charset=UTF-8"); logger.info("post url:" + getProperty(KYLIN_QUERY_API_URL)); HttpPost postRequest = new HttpPost(getProperty(KYLIN_QUERY_API_URL)); postRequest.setEntity(entity); postRequest.addHeader("Authorization", "Basic " + new String(encodeBytes)); postRequest.addHeader("Accept-Encoding", "UTF-8"); HttpClient httpClient = HttpClientBuilder.create().build(); return httpClient.execute(postRequest); } private InterpreterResult executeQuery(String sql) throws IOException { HttpResponse response = prepareRequest(sql); if (response.getStatusLine().getStatusCode() != 200) { logger.error("failed to execute query: " + response.getEntity().getContent().toString()); return new InterpreterResult(InterpreterResult.Code.ERROR, "Failed : HTTP error code " + response.getStatusLine().getStatusCode()); } BufferedReader br = new BufferedReader(new InputStreamReader((response.getEntity().getContent()))); StringBuilder sb = new StringBuilder(); String output; logger.info("Output from Server .... \n"); while ((output = br.readLine()) != null) { logger.info(output); sb.append(output).append('\n'); } InterpreterResult rett = new InterpreterResult(InterpreterResult.Code.SUCCESS, formatResult(sb.toString())); return rett; } private String formatResult(String msg) { StringBuilder res = new StringBuilder("%table "); Matcher ml = KYLIN_TABLE_FORMAT_REGEX_LABEL.matcher(msg); while (!ml.hitEnd() && ml.find()) { res.append(ml.group(1) + " \t"); } res.append(" \n"); Matcher mr = KYLIN_TABLE_FORMAT_REGEX.matcher(msg); String table = null; while (!mr.hitEnd() && mr.find()) { table = mr.group(1); } String[] row = table.split("\"],\\[\""); for (int i = 0; i < row.length; i++) { String[] col = row[i].split("\",\""); for (int j = 0; j < col.length; j++) { res.append(col[j] + " \t"); } res.append(" \n"); } return res.toString(); } }