初识Kafka----------Centos上单机部署、服务启动、JAVA客户端调用

两个消费端均能收到服务端的信息。

7、尝试用java代码来接收信息，首先建立一个MAVEN工程，POM.xml文件加入依赖：

<dependency>
<groupId>org.apache.kafka</groupId>
<artifactId>kafka-clients</artifactId>
<version>0.8.2.1</version>
</dependency>

<dependency>
<groupId>org.apache.kafka</groupId>
<artifactId>kafka_2.11</artifactId>
<version>0.8.2.1</version>
</dependency>

然后运行安装代码构建完成。具体调用代码如下

import java.util.List;
import java.util.Properties;
import java.util.concurrent.TimeUnit;

import kafka.consumer.Consumer;
import kafka.consumer.ConsumerConfig;
import kafka.consumer.ConsumerIterator;
import kafka.consumer.KafkaStream;
import kafka.consumer.Whitelist;
import kafka.javaapi.consumer.ConsumerConnector;
import kafka.message.MessageAndMetadata;

import org.apache.kafka.common.utils.CollectionUtils;

/**
* File Name:KafkaConsumer.java
* Package_Name:kafkaTest
* date:2017-3-25上午10:00:56
* Author : cao.zhi10
*
*/
public class KafkaConsumer {
public static void main(String[] args) throws Exception {
Properties properties = new Properties();
properties.put("zookeeper.connect", "192.168.118.131:3181");
properties.put("auto.commit.enable", "true");
properties.put("auto.commit.interval.ms", "60000");
properties.put("group.id", "test");

ConsumerConfig consumerConfig = new ConsumerConfig(properties);

ConsumerConnector javaConsumerConnector = Consumer.createJavaConsumerConnector(consumerConfig);

//topic的过滤器
Whitelist whitelist = new Whitelist("test");
List<KafkaStream<byte[], byte[]>> partitions = javaConsumerConnector.createMessageStreamsByFilter(whitelist);

if (partitions==null) {
System.out.println("empty!");
TimeUnit.SECONDS.sleep(1);
}

//消费消息
for (KafkaStream<byte[], byte[]> partition : partitions) {

ConsumerIterator<byte[], byte[]> iterator = partition.iterator();
while (iterator.hasNext()) {
MessageAndMetadata<byte[], byte[]> next = iterator.next();
System.out.println("partiton:" + next.partition());
System.out.println("offset:" + next.offset());
System.out.println("接收到message:" + new String(next.message(), "utf-8"));
}
}
}
}

执行main方法，一直报DISCONNECT异常，仔细分析启动日志发现一直在去尝试调用 localhost：9092 。搜索了下该问题，网上给的解决方案是修改 service.properties 里面的hostname 信息，但是目前最新版本已经取消了该节点，目前必须使用 listeners.

 8、重新启动服务，生产者，消费者（注意必须用IP地址启动，否则会报错）

 

 

问题得到解决