Kafka消费者 API(自动提交offset)

 1源码demo

package com.kpwong.consumer; import org.apache.kafka.clients.consumer.ConsumerConfig; import org.apache.kafka.clients.consumer.ConsumerRecord; import org.apache.kafka.clients.consumer.ConsumerRecords; import org.apache.kafka.clients.consumer.KafkaConsumer; import java.util.Arrays; import java.util.Properties; public class MyConsumer { public static void main(String[] args) { Properties prop = new Properties(); prop.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG,"hadoop202:9092");
 //自动提交offset prop.put(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG,true); prop.put(ConsumerConfig.AUTO_COMMIT_INTERVAL_MS_CONFIG,"1000"); prop.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG,"org.apache.kafka.common.serialization.StringDeserializer"); prop.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG,"org.apache.kafka.common.serialization.StringDeserializer"); //消费者组
        prop.put(ConsumerConfig.GROUP_ID_CONFIG,"bigdata"); //创建消费者
        KafkaConsumer<String, String> consumer = new KafkaConsumer<String, String>(prop); //订阅主题
        consumer.subscribe(Arrays.asList("two")); while (true) { //获取数据
            ConsumerRecords<String, String> records = consumer.poll(100); //遍历records
            for (ConsumerRecord<String, String> record : records) { System.out.println("consumer : "+" partition:"+record.partition()+" key :"+record.key()+"------value :"+record.value()); } } // consumer.close();
 } }

2:运行结果:

 3:实现命令行 --from-beginning 效果

        //--from-beginning
        prop.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG,"earliest");
        //消费者组
        prop.put(ConsumerConfig.GROUP_ID_CONFIG,"bigdata2");

注意：要换组名 才行

运行效果: