我是Kafka的新手 . 我开始在Kafka做我面临的问题请帮助我提前解决这个问题 . 首先,我正在编写 生产环境 者API,它工作正常,但不显示消费者API消息 .
我的代码是这样的:
import java.util.Arrays;
import java.util.Properties;
import org.apache.kafka.clients.consumer.KafkaConsumer;
import org.apache.kafka.clients.consumer.ConsumerRecords;
import org.apache.kafka.clients.consumer.ConsumerRecord;
public class ConsumerGroup {
public static void main(String[] args) throws Exception {
String topic = "Hello-Kafka";
String group = "myGroup";
Properties props = new Properties();
props.put("bootstrap.servers", "XXX.XX.XX.XX:9092");
props.put("group.id", group);
props.put("key.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
props.put("value.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
KafkaConsumer<String, String> consumer = new KafkaConsumer<String, String>(props);
try {
consumer.subscribe(Arrays.asList(topic));
System.out.println("Subscribed to topic " + topic);
ConsumerRecords<String, String> records = consumer.poll(100);
System.out.println("records ::" + records);
System.out.println(records.toString());
for (ConsumerRecord<String, String> record : records) {
System.out.println("Record::" + record.offset());
System.out.println(record.key());
System.out.println(record.value());
}
consumer.commitSync();
} catch (Exception e) {
e.printStackTrace();
} finally {
consumer.commitSync();
consumer.close();
}
}
}
回复::
订阅主题Hello-Kafka记录:: org.apache.kafka.clients.consumer.ConsumerRecords@76b0bfab org.apache.kafka.clients.consumer.ConsumerRecords@76b0bfab
这里没有打印偏移,键,值控制不是为了(ConsumerRecord记录:记录){为循环它自己请帮助我 .
1 回答
您正在尝试打印空记录,因此只有records.toString()在您的代码中打印,这基本上是类的名称 .
我对您的代码进行了一些更改并使其正常工作 . 看看这是否有帮助 .