kafka用java生產和消費消息問題

初次使用kafka踩了好多坑，分享如下：

      消費者發送消息看似成功，但在虛擬機liunx上也獲取不到。需要在配置config/server.properties配置文件中添加遠程監聽如下：

             advertised.listeners=PLAINTEXT://服務器外網ip:9092  註釋掉listeners=PLAINTEXT://:9092

     好了，重啓之後生成者可以生產消息了。但是又發先消費者無法消費消息，查找了多資料。最後嘗試註釋掉maven pom文件中對kafka-streams的依賴測試成功。可能kafka結合streams使用方式不是這種方式導致。代碼如下：

----------------------pom文件-----------------------------------

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.project.kafka</groupId>
  <artifactId>kafka</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>war</packaging>
  
  <dependencies>
      <dependency>
        <groupId>org.apache.kafka</groupId>
        <artifactId>kafka-clients</artifactId>
        <version>2.3.0</version>
      </dependency>
      <!-- 
      <dependency>
        <groupId>org.apache.kafka</groupId>
        <artifactId>kafka-streams</artifactId>
        <version>2.3.0</version>
    </dependency>
     -->
  </dependencies>
</project>

--------------------------------------------Producer-------------------------------------------

package com.test;

import java.util.Properties;

import org.apache.kafka.clients.producer.KafkaProducer;
import org.apache.kafka.clients.producer.ProducerRecord;

public class Producer {

    public static void main(String[] args) {
        Properties props = new Properties();
        props.put("bootstrap.servers", "192.168.56.101:9092");
        props.put("acks", "all");
        props.put("retries", 0);
        props.put("batch.size", 16384);
        props.put("linger.ms", 1);
        props.put("buffer.memory", 33554432);
        props.put("key.serializer", "org.apache.kafka.common.serialization.StringSerializer");
        props.put("value.serializer", "org.apache.kafka.common.serialization.StringSerializer");

        org.apache.kafka.clients.producer.Producer<String, String> producer = new KafkaProducer<String, String>(props);
        for (int i = 0; i < 100; i++) {
            producer.send(new ProducerRecord<String, String>("testtt", Integer.toString(i), Integer.toString(i)));

            System.out.println("==============");
        }

        producer.close();
    }
}

----------------------------------------------Consumer -----------------------------------------------------------------

package com.test;

import java.time.Duration;
import java.util.Arrays;
import java.util.Properties;

import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.apache.kafka.clients.consumer.ConsumerRecords;
import org.apache.kafka.clients.consumer.KafkaConsumer;

public class Consumer {
    public static void main(String[] args) {
         Properties props = new Properties();
         props.setProperty("bootstrap.servers", "192.168.56.101:9092");
         props.setProperty("group.id", "test");
         props.setProperty("enable.auto.commit", "true");
         props.setProperty("auto.commit.interval.ms", "1000");
         props.setProperty("key.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
         props.setProperty("value.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
         KafkaConsumer<String, String> consumer = new KafkaConsumer<String,String>(props);
         consumer.subscribe(Arrays.asList("testtt"));
         while (true) {
             ConsumerRecords<String, String> records = consumer.poll(Duration.ofMillis(100));
             for (ConsumerRecord<String, String> record : records)
                 System.out.printf("offset = %d, key = %s, value = %s%n", record.offset(), record.key(), record.value());
         }
    }
}