Java tutorial
/** * Copyright 2016 Yahoo Inc. * * 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 com.yahoo.pulsar.client.cli; import static org.apache.commons.lang3.StringUtils.isNotBlank; import static org.apache.commons.lang3.StringUtils.isBlank; import java.io.FileInputStream; import java.net.MalformedURLException; import java.util.Arrays; import java.util.Properties; import org.apache.commons.lang3.StringUtils; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.beust.jcommander.JCommander; import com.beust.jcommander.Parameter; import com.beust.jcommander.ParameterException; import com.beust.jcommander.Parameters; import com.yahoo.pulsar.client.api.ClientConfiguration; import com.yahoo.pulsar.client.api.PulsarClientException.UnsupportedAuthenticationException; @Parameters(commandDescription = "Produce or consume messages on a specified topic") public class PulsarClientTool { private static final Logger LOG = LoggerFactory.getLogger(PulsarClientTool.class); @Parameter(names = { "--url" }, description = "Broker URL to which to connect.") String serviceURL = null; @Parameter(names = { "--auth-plugin" }, description = "Authentication plugin class name.") String authPluginClassName = null; @Parameter(names = { "--auth-params" }, description = "Authentication parameters, e.g., \"key1:val1,key2:val2\".") String authParams = null; @Parameter(names = { "-h", "--help", }, help = true, description = "Show this help.") boolean help; boolean useTls = false; boolean tlsAllowInsecureConnection = false; String tlsTrustCertsFilePath = null; JCommander commandParser; CmdProduce produceCommand; CmdConsume consumeCommand; public PulsarClientTool(Properties properties) throws MalformedURLException { this.serviceURL = StringUtils.isNotBlank(properties.getProperty("brokerServiceUrl")) ? properties.getProperty("brokerServiceUrl") : properties.getProperty("webServiceUrl"); // fallback to previous-version serviceUrl property to maintain backward-compatibility if (StringUtils.isBlank(this.serviceURL)) { this.serviceURL = properties.getProperty("serviceUrl"); } this.authPluginClassName = properties.getProperty("authPlugin"); this.authParams = properties.getProperty("authParams"); this.useTls = Boolean.parseBoolean(properties.getProperty("useTls")); this.tlsAllowInsecureConnection = Boolean .parseBoolean(properties.getProperty("tlsAllowInsecureConnection")); this.tlsTrustCertsFilePath = properties.getProperty("tlsTrustCertsFilePath"); produceCommand = new CmdProduce(); consumeCommand = new CmdConsume(); this.commandParser = new JCommander(); commandParser.setProgramName("pulsar-client"); commandParser.addObject(this); commandParser.addCommand("produce", produceCommand); commandParser.addCommand("consume", consumeCommand); } private void updateConfig() throws UnsupportedAuthenticationException, MalformedURLException { ClientConfiguration configuration = new ClientConfiguration(); if (isNotBlank(this.authPluginClassName)) { configuration.setAuthentication(authPluginClassName, authParams); } configuration.setUseTls(this.useTls); configuration.setTlsAllowInsecureConnection(this.tlsAllowInsecureConnection); configuration.setTlsTrustCertsFilePath(this.tlsTrustCertsFilePath); this.produceCommand.updateConfig(this.serviceURL, configuration); this.consumeCommand.updateConfig(this.serviceURL, configuration); } public int run(String[] args) { try { if (isBlank(this.serviceURL)) { commandParser.usage(); return -1; } commandParser.parse(args); if (help) { commandParser.usage(); return 0; } try { this.updateConfig(); // If the --url, --auth-plugin, or --auth-params parameter are not specified, // it will default to the values passed in by the constructor } catch (MalformedURLException mue) { System.out.println("Unable to parse URL " + this.serviceURL); commandParser.usage(); return -1; } catch (UnsupportedAuthenticationException exp) { System.out.println("Failed to load an authentication plugin"); commandParser.usage(); return -1; } String chosenCommand = commandParser.getParsedCommand(); if ("produce".equals(chosenCommand)) { return produceCommand.run(); } else if ("consume".equals(chosenCommand)) { return consumeCommand.run(); } else { commandParser.usage(); return -1; } } catch (Exception e) { System.out.println(e.getMessage()); if (e instanceof ParameterException) { commandParser.usage(); } else { e.printStackTrace(); } return -1; } } public static void main(String[] args) throws Exception { if (args.length == 0) { System.out.println("Usage: pulsar-client CONF_FILE_PATH [options] [command] [command options]"); System.exit(-1); } String configFile = args[0]; Properties properties = new Properties(); if (configFile != null) { FileInputStream fis = null; try { fis = new FileInputStream(configFile); properties.load(fis); } finally { if (fis != null) { fis.close(); } } } PulsarClientTool clientTool = new PulsarClientTool(properties); int exit_code = clientTool.run(Arrays.copyOfRange(args, 1, args.length)); System.exit(exit_code); } }