KafkaTemplate.send（键，值，主题）与自定义分区程序？

Question

我看到并实现了带有默认分区程序类的方法 KafkaTemplate.send（TOPIC，message） 。

但是在这里，我没有传递密钥。我有一个简单的 自定义分区程序类 ，我也想发送到像 KafkaTemplate（TOPIC，key，message） 这样的kafka服务器。 strong>在producerConfig中我在哪里设置了我的customPartitioner类来进行分区。

我看到了这个Will send(Topic, Key, Message) method of KafkaTemplate calls Partition method if I provide custom Partitioner?，但我没有完全明白。

1. 我简单的customPartitioner类：

public class CustomPartitionar implements Partitioner {
   private PartitionMapper newMapper;
   public CustomPartitionar(){
       newMapper = new PartitionMapper();
   }
   @Override
   public void configure(Map<String, ?> configs) {

   }
   @Override
   public int partition(String topic, Object key, byte[] keyBytes, Object value, byte[] valueBytes,Cluster cluster) {
       int partition = 0;
       String userName = (String) key;
       // Find the id of current user based on the username from another mapper class
       Integer userId = newMapper.findUserId(userName);
       // If the userId not found, default partition is 0
       if (userId != null) {
           partition = userId;
       }
       return partition;
   }
   @Override
   public void close() {
   }
}

1. 将此类添加到producerFactory：

config.put(ProducerConfig.PARTITIONER_CLASS_CONFIG, CustomPartitionar.class);

1. 实际上，我的 密钥 将从 “ message.getReceiver（）” 和 < em> topic 将从 “ message.getTopic（）” 获得，因此我的邮件将转到所需的主题，并且分区属于该用户/group..so，我只想发送：

KafkaTemplate.send(message.getTopic(),message.getReceiver(),message)

这可以通过简单的方式实现还是我错过了什么？

Answer 1

KafkaTemplate有几种send方法：

/**
 * Send the data to the default topic with no key or partition.
 * @param data The data.
 * @return a Future for the {@link SendResult}.
 */
ListenableFuture<SendResult<K, V>> sendDefault(V data);

/**
 * Send the data to the default topic with the provided key and no partition.
 * @param key the key.
 * @param data The data.
 * @return a Future for the {@link SendResult}.
 */
ListenableFuture<SendResult<K, V>> sendDefault(K key, V data);

/**
 * Send the data to the default topic with the provided key and partition.
 * @param partition the partition.
 * @param key the key.
 * @param data the data.
 * @return a Future for the {@link SendResult}.
 */
ListenableFuture<SendResult<K, V>> sendDefault(Integer partition, K key, V data);

/**
 * Send the data to the default topic with the provided key and partition.
 * @param partition the partition.
 * @param timestamp the timestamp of the record.
 * @param key the key.
 * @param data the data.
 * @return a Future for the {@link SendResult}.
 * @since 1.3
 */
ListenableFuture<SendResult<K, V>> sendDefault(Integer partition, Long timestamp, K key, V data);

/**
 * Send the data to the provided topic with no key or partition.
 * @param topic the topic.
 * @param data The data.
 * @return a Future for the {@link SendResult}.
 */
ListenableFuture<SendResult<K, V>> send(String topic, V data);

/**
 * Send the data to the provided topic with the provided key and no partition.
 * @param topic the topic.
 * @param key the key.
 * @param data The data.
 * @return a Future for the {@link SendResult}.
 */
ListenableFuture<SendResult<K, V>> send(String topic, K key, V data);

/**
 * Send the data to the provided topic with the provided key and partition.
 * @param topic the topic.
 * @param partition the partition.
 * @param key the key.
 * @param data the data.
 * @return a Future for the {@link SendResult}.
 */
ListenableFuture<SendResult<K, V>> send(String topic, Integer partition, K key, V data);

/**
 * Send the data to the provided topic with the provided key and partition.
 * @param topic the topic.
 * @param partition the partition.
 * @param timestamp the timestamp of the record.
 * @param key the key.
 * @param data the data.
 * @return a Future for the {@link SendResult}.
 * @since 1.3
 */
ListenableFuture<SendResult<K, V>> send(String topic, Integer partition, Long timestamp, K key, V data);

/**
 * Send the provided {@link ProducerRecord}.
 * @param record the record.
 * @return a Future for the {@link SendResult}.
 * @since 1.3
 */
ListenableFuture<SendResult<K, V>> send(ProducerRecord<K, V> record);

/**
 * Send a message with routing information in message headers. The message payload
 * may be converted before sending.
 * @param message the message to send.
 * @return a Future for the {@link SendResult}.
 * @see org.springframework.kafka.support.KafkaHeaders#TOPIC
 * @see org.springframework.kafka.support.KafkaHeaders#PARTITION_ID
 * @see org.springframework.kafka.support.KafkaHeaders#MESSAGE_KEY
 */
ListenableFuture<SendResult<K, V>> send(Message<?> message);