1.java连接pulsar服务

目录

• 是什么
• 安装
• Java客户端
  • 1.引入GAV
  • 2.创建配置项
  • 3.验证测试
• 其他及代码下载

是什么

Pulsar 是一个用于服务器到服务器的消息系统，具有多租户、高性能等优势。详见

安装

本文主练习怎么用，本地搭建了一个单机版，无非就是wget、tar、start这些命令，详见

Java客户端

1.引入GAV

        <!-- https://mvnrepository.com/artifact/org.apache.pulsar/pulsar-client -->
        <dependency>
            <groupId>org.apache.pulsar</groupId>
            <artifactId>pulsar-client</artifactId>
            <version>2.8.0</version>
        </dependency>

2.创建配置项

用于连接Pulsar等配置

• Yml配置

  pulsar:
    url: 10.20.30.228:6650
  #  url: 10.20.30.228:6650,10.20.30.228:6651 #集群配置
  

• 新增配置类

  package com.project.pulsar.conf;
  
  import org.apache.pulsar.client.api.PulsarClient;
  import org.apache.pulsar.client.api.PulsarClientException;
  import org.springframework.beans.factory.annotation.Value;
  import org.springframework.context.annotation.Bean;
  import org.springframework.context.annotation.Configuration;
  
  @Configuration
  public class PulsarConf {
      @Value("${pulsar.url}")
      String url;
  
      @Bean
      public PulsarClient pulsarFactory(){
          PulsarClient client = null;
          try {
              client = PulsarClient.builder()
                      .serviceUrl("pulsar://"+url)
                      .build();
          } catch (PulsarClientException e) {
          }
          return client;
      }
  }
  

3.验证测试

​ 通过简单生产-消费测试配置是否正常

• 创建BaseController

  注意，subscriptionName要保证唯一

  package com.project.pulsar.base;
  
  import com.project.pulsar.conf.PulsarConf;
  import org.apache.pulsar.client.api.*;
  import org.springframework.beans.factory.annotation.Autowired;
  import org.springframework.context.annotation.Bean;
  import org.springframework.web.bind.annotation.GetMapping;
  import org.springframework.web.bind.annotation.RestController;
  
  import java.util.HashMap;
  import java.util.Map;
  
  @RestController
  public class BaseController {
      @Autowired
      PulsarConf pulsarConf;
  
      /**
       * 生产消息
       * @param msg
       * @throws PulsarClientException
       */
      @GetMapping("/base/sendMsg")
      public MessageId sendMsg(String msg) throws PulsarClientException {
          PulsarClient pulsarFactory = pulsarConf.pulsarFactory();
  
          Producer<byte[]> producer1 = pulsarFactory.newProducer()
                  .topic("my-topic")
  
                  .create();
          // 然后你就可以发送消息到指定的broker 和topic上：
          return producer1.send(msg.getBytes());
      }
  
      /**
       * 手动执行获取消息
       * @throws PulsarClientException
       */
      @GetMapping("/base/comsumer")
      public void comsumerByArtificial() throws PulsarClientException {
          PulsarClient pulsarFactory = pulsarConf.pulsarFactory();
          Consumer<byte[]> consumer = pulsarFactory.newConsumer()
                  .topic("my-topic")
                  .subscriptionName("my-subscription")
                  .subscribe();
          Message<byte[]> receive = consumer.receive();
          System.out.println(new String(receive.getData()));
          consumer.acknowledge(receive);//确认消息被消费
          consumer.close();
      }
  
      /**
       * 自动监听消费消息
       * @throws PulsarClientException
       */
      @Bean
      public void comsumerByListener() throws PulsarClientException {
          MessageListener myMessageListener = (consumer, msg) -> {
              try {
                  System.out.println("Message received: " + new String(msg.getData()));
                  consumer.acknowledge(msg);
              } catch (Exception e) {
                  consumer.negativeAcknowledge(msg);
              }
          };
          PulsarClient pulsarFactory = pulsarConf.pulsarFactory();
          pulsarFactory.newConsumer()
                  .topic("my-topic")
                  .subscriptionName("my-subscriptionByListener")
                  .messageListener(myMessageListener)
                  .subscribe();
      }
  
  }
  
  

• 生产消息

  [127.0.0.1:9999/base/sendMsg?msg=Hello RB](http://127.0.0.1:9999/base/sendMsg?msg=Hello RB)

• 消费消息

  • 在生产后，如果采用监听模式，会自动消费
  • 在生产后，如果采用手动模式，执行127.0.0.1:9999/base/comsumer会被消费，如队列中无消费，则会阻塞等待

其他及代码下载

• topic不用显式创建，当消息发送或消费者建立连接时，如未创建会自动创建
• 代码见此Base包下