Kafka3.0.0版本——消费者（自动提交 offset）

迈不过友情╰ 2024-03-04 08:03 65阅读 0赞

#### 目录 ####

*   *  一、自动提交offset的相关参数
     *  二、消费者（自动提交 offset）代码示例

### 一、自动提交offset的相关参数 ###

*  **官网文档**  
    ![在这里插入图片描述][2bc4eece1aee4a588dda0c9aa5cf1b43.png]
 *  **参数解释**
    
    <table> 
     <thead> 
      <tr> 
       <th>参数</th> 
       <th>描述</th> 
      </tr> 
     </thead> 
     <tbody> 
      <tr> 
       <td>enable.auto.commi</td> 
       <td>默认值为 true，消费者会自动周期性地向服务器提交偏移量。</td> 
      </tr> 
      <tr> 
       <td>auto.commit.interval.ms</td> 
       <td>如果设置了 enable.auto.commit 的值为 true， 则该值定义了消费者偏移量向 Kafka 提交的频率，默认 5s。</td> 
      </tr> 
     </tbody> 
    </table>
 *  **图解分析**
    
    ![在这里插入图片描述][e3bf29455e214aeb95a3ded76305015b.png]

### 二、消费者（自动提交 offset）代码示例 ###

*  **消费者自动提交 offset代码**
    
        // 自动提交
        properties.put(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG,true);
        // 提交时间间隔 1秒
        properties.put(ConsumerConfig.AUTO_COMMIT_INTERVAL_MS_CONFIG,1000);
 *  **消费者自动提交 offset代码完整代码**
    
        package com.xz.kafka.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 org.apache.kafka.common.serialization.StringDeserializer;
        
        import java.time.Duration;
        import java.util.ArrayList;
        import java.util.Properties;
        
        public class CustomConsumerAutoOffset {
              
        
            public static void main(String[] args) {
              
        
                // 配置
                Properties properties = new Properties();
        
                // 连接 bootstrap.servers
                properties.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG,"192.168.136.27:9092,192.168.136.28:9092,192.168.136.29:9092");
        
                // 反序列化
                properties.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
                properties.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
        
                // 配置消费者组id
                properties.put(ConsumerConfig.GROUP_ID_CONFIG,"test3");
        
                // 自动提交
                properties.put(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG,true);
        
                // 提交时间间隔 1秒
                properties.put(ConsumerConfig.AUTO_COMMIT_INTERVAL_MS_CONFIG,1000);
        
                // 1 创建一个消费者  "", "hello"
                KafkaConsumer<String, String> kafkaConsumer = new KafkaConsumer<>(properties);
        
                // 2 订阅主题 first
                ArrayList<String> topics = new ArrayList<>();
                topics.add("sevenTopic");
                kafkaConsumer.subscribe(topics);
        
                // 3 消费数据
                while (true){
              
        
                    ConsumerRecords<String, String> consumerRecords = kafkaConsumer.poll(Duration.ofSeconds(1));
        
                    for (ConsumerRecord<String, String> consumerRecord : consumerRecords) {
              
                        System.out.println(consumerRecord);
                    }
                }
            }
        }

[2bc4eece1aee4a588dda0c9aa5cf1b43.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/04/96f26a787cff4da3a15cefa10ac42910.png
[e3bf29455e214aeb95a3ded76305015b.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/04/b21a07870c264ee0ae3fcfdc373ddbcd.png