一、生产者,开启事务。
package com.cisdi.dsp.modules.metaAnalysis.rest.kafka2023;
import org.apache.kafka.clients.producer.KafkaProducer;
import org.apache.kafka.clients.producer.ProducerConfig;
import org.apache.kafka.clients.producer.ProducerRecord;
import org.apache.kafka.clients.producer.RecordMetadata;
import org.apache.kafka.common.serialization.StringSerializer;
import java.util.Date;
import java.util.Properties;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
public class KafkaTest22 {
public static void main(String[] args) {
Properties properties= new Properties();
properties.setProperty(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
properties.setProperty(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
properties.setProperty(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG,"xx.xx.xx.xx:9092");
properties.setProperty(ProducerConfig.ENABLE_IDEMPOTENCE_CONFIG, "true");
properties.setProperty(ProducerConfig.RETRIES_CONFIG, "2");
properties.setProperty(ProducerConfig.MAX_IN_FLIGHT_REQUESTS_PER_CONNECTION, "4");
properties.setProperty(ProducerConfig.TRANSACTIONAL_ID_CONFIG, "myTransaction");
KafkaProducer<String,String> kafkaProducer=new KafkaProducer<String, String>(properties);
ProducerRecord<String,String> producerRecord=new ProducerRecord<>("study2024",0,"fff","hello sister,now is: "+ new Date());
kafkaProducer.initTransactions();
kafkaProducer.beginTransaction();
try{
Future<RecordMetadata> future = kafkaProducer.send(producerRecord);
long offset = 0;
try {
offset = future.get().offset();
} catch (InterruptedException e) {
e.printStackTrace();
} catch (ExecutionException e) {
e.printStackTrace();
}
System.out.println(offset);
Thread.sleep(60000);
kafkaProducer.commitTransaction();
} catch (Exception ex){
kafkaProducer.abortTransaction();
}
kafkaProducer.close();
}
}
二、消费者,设置隔离级别为"read_committed"文章来源:https://www.toymoban.com/news/detail-682757.html
package com.cisdi.dsp.modules.metaAnalysis.rest.kafka2023;
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 org.apache.kafka.clients.producer.ProducerConfig;
import org.apache.kafka.common.TopicPartition;
import org.apache.kafka.common.serialization.StringDeserializer;
import org.apache.kafka.common.serialization.StringSerializer;
import java.time.Duration;
import java.time.temporal.TemporalUnit;
import java.util.Arrays;
import java.util.Properties;
import java.util.concurrent.TimeUnit;
public class KafkaTest23 {
private static Properties getProperties(){
Properties properties=new Properties();
properties.setProperty(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
properties.setProperty(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
properties.setProperty(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG,"xx.xx.xx.xx:9092");
properties.setProperty(ConsumerConfig.GROUP_ID_CONFIG,"testGroup");
properties.setProperty(ConsumerConfig.ISOLATION_LEVEL_CONFIG, "read_committed");
//properties.setProperty(ConsumerConfig.ISOLATION_LEVEL_CONFIG, "read_uncommitted");
return properties;
}
public static void main(String[] args) {
KafkaConsumer<String,String> myConsumer=new KafkaConsumer<String, String>(getProperties());
String topic="study2024";
myConsumer.subscribe(Arrays.asList(topic));
while(true){
ConsumerRecords<String,String> consumerRecords=myConsumer.poll(Duration.ofMillis(5000));
for(ConsumerRecord record: consumerRecords){
System.out.println(record.value());
System.out.println("record offset is: "+record.offset());
}
}
}
}
三、运行结果,按照上述配置,当生产者发送消息并从kafka broker获取到offset后就会sleep,在生产者sleep的时候,消费者是获取不到消息的,只有sleep完成并提交事务之后,消费者才会获取到消息文章来源地址https://www.toymoban.com/news/detail-682757.html
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