| /** |
| * 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.pulsar.client.cli; |
| |
| import java.io.ByteArrayOutputStream; |
| import java.io.IOException; |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.concurrent.TimeUnit; |
| |
| import org.apache.commons.io.HexDump; |
| import org.apache.pulsar.client.api.ClientConfiguration; |
| import org.apache.pulsar.client.api.Consumer; |
| import org.apache.pulsar.client.api.ConsumerConfiguration; |
| import org.apache.pulsar.client.api.Message; |
| import org.apache.pulsar.client.api.PulsarClient; |
| import org.apache.pulsar.client.api.PulsarClientException; |
| import org.apache.pulsar.client.api.SubscriptionType; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import com.beust.jcommander.Parameter; |
| import com.beust.jcommander.ParameterException; |
| import com.beust.jcommander.Parameters; |
| import com.google.common.util.concurrent.RateLimiter; |
| |
| /** |
| * pulsar-client consume command implementation. |
| * |
| */ |
| @Parameters(commandDescription = "Consume messages from a specified topic") |
| public class CmdConsume { |
| |
| private static final Logger LOG = LoggerFactory.getLogger(PulsarClientTool.class); |
| private static final String MESSAGE_BOUNDARY = "----- got message -----"; |
| |
| @Parameter(description = "TopicName", required = true) |
| private List<String> mainOptions = new ArrayList<String>(); |
| |
| @Parameter(names = { "-t", "--subscription-type" }, description = "Subscription type: Exclusive, Shared, Failover.") |
| private SubscriptionType subscriptionType = SubscriptionType.Exclusive; |
| |
| @Parameter(names = { "-s", "--subscription-name" }, required = true, description = "Subscription name.") |
| private String subscriptionName; |
| |
| @Parameter(names = { "-n", |
| "--num-messages" }, description = "Number of messages to consume, 0 means to consume forever.") |
| private int numMessagesToConsume = 1; |
| |
| @Parameter(names = { "--hex" }, description = "Display binary messages in hex.") |
| private boolean displayHex = false; |
| |
| @Parameter(names = { "-r", "--rate" }, description = "Rate (in msg/sec) at which to consume, " |
| + "value 0 means to consume messages as fast as possible.") |
| private double consumeRate = 0; |
| |
| private String serviceURL = null; |
| ClientConfiguration clientConfig; |
| |
| public CmdConsume() { |
| // Do nothing |
| } |
| |
| /** |
| * Set client configuration. |
| * |
| */ |
| public void updateConfig(String serviceURL, ClientConfiguration newConfig) { |
| this.serviceURL = serviceURL; |
| this.clientConfig = newConfig; |
| } |
| |
| /** |
| * Interprets the message to create a string representation |
| * |
| * @param message |
| * The message to interpret |
| * @param displayHex |
| * Whether to display BytesMessages in hexdump style, ignored for simple text messages |
| * @return String representation of the message |
| */ |
| private String interpretMessage(Message message, boolean displayHex) throws IOException { |
| byte[] msgData = message.getData(); |
| ByteArrayOutputStream out = new ByteArrayOutputStream(); |
| if (!displayHex) { |
| return new String(msgData); |
| } else { |
| HexDump.dump(msgData, 0, out, 0); |
| return new String(out.toByteArray()); |
| } |
| } |
| |
| /** |
| * Run the consume command. |
| * |
| * @return 0 for success, < 0 otherwise |
| */ |
| public int run() throws PulsarClientException, IOException { |
| if (mainOptions.size() != 1) |
| throw (new ParameterException("Please provide one and only one topic name.")); |
| if (this.serviceURL == null || this.serviceURL.isEmpty()) |
| throw (new ParameterException("Broker URL is not provided.")); |
| if (this.subscriptionName == null || this.subscriptionName.isEmpty()) |
| throw (new ParameterException("Subscription name is not provided.")); |
| if (this.numMessagesToConsume < 0) |
| throw (new ParameterException("Number of messages should be zero or positive.")); |
| |
| String topic = this.mainOptions.get(0); |
| int numMessagesConsumed = 0; |
| int returnCode = 0; |
| |
| try { |
| ConsumerConfiguration consumerConf = new ConsumerConfiguration(); |
| consumerConf.setSubscriptionType(this.subscriptionType); |
| PulsarClient client = PulsarClient.create(this.serviceURL, this.clientConfig); |
| Consumer consumer = client.subscribe(topic, this.subscriptionName, consumerConf); |
| |
| RateLimiter limiter = (this.consumeRate > 0) ? RateLimiter.create(this.consumeRate) : null; |
| while (this.numMessagesToConsume == 0 || numMessagesConsumed < this.numMessagesToConsume) { |
| if (limiter != null) { |
| limiter.acquire(); |
| } |
| |
| Message msg = consumer.receive(5, TimeUnit.SECONDS); |
| if (msg == null) { |
| LOG.warn("No message to consume after waiting for 20 seconds."); |
| } else { |
| numMessagesConsumed += 1; |
| System.out.println(MESSAGE_BOUNDARY); |
| String output = this.interpretMessage(msg, displayHex); |
| System.out.println(output); |
| consumer.acknowledge(msg); |
| } |
| } |
| client.close(); |
| } catch (Exception e) { |
| LOG.error("Error while consuming messages"); |
| LOG.error(e.getMessage(), e); |
| returnCode = -1; |
| } finally { |
| LOG.info("{} messages successfully consumed", numMessagesConsumed); |
| } |
| |
| return returnCode; |
| } |
| } |