拉取kafka消息

package kafka;

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

import java.util.Collections;
import java.util.Properties;

public class MyConsumer {
        private static KafkaConsumer consumer;

    static {
        Properties properties = new Properties();
        properties.put("bootstrap.servers", "127.0.0.1:9092");
        properties.put("group.id", "CountryCounter");
        properties.put("key.deserializer",
                "org.apache.kafka.common.serialization.StringDeserializer");
        properties.put("value.deserializer",
                "org.apache.kafka.common.serialization.StringDeserializer");
        consumer = new KafkaConsumer(properties);
    }

    private static void consumerTest(){
        //订阅topic
        consumer.subscribe(Collections.singleton("kafka-study"));

        try {
            while (true){
                //在100ms内等待Kafka的broker返回数据.超市参数指定poll在多久之后可以返回，不管有没有可用的数据都要返回
                ConsumerRecords records =  consumer.poll(100);
                 for (ConsumerRecord record : records) {
                     System.out.println(("topic:"+record.topic() +" " + "offset:"+ record.offset() +" "+"key:"+ record.key()
                             +" "+"value:"+ record.value()));
              }
            }
        }catch (Exception e){
            System.out.println("error:"+e);
        }finally {
            consumer.close();
        }

    }

    public static void main(String[] args) {
        consumerTest();
    }


}