Sender (Reactor Kafka 1.0.0.M1)

Type Parameters:

K - outgoing record key type

V - outgoing record value type
```
public interface Sender<K,V>
```
Reactive producer that sends outgoing records to topic partitions of a Kafka cluster. The producer is thread-safe and can be used to publish records to multiple partitions. It is recommended that a single Sender is shared for each record type in a client application.

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method and Description
`void`	`close()` Closes this sender and the underlying Kafka producer and releases all resources allocated to it.
`static <K,V> Sender<K,V>`	`create(SenderOptions<K,V> options)` Creates a Kafka sender that appends records to Kafka topic partitions.
`<T> Mono<T>`	`doOnProducer(Function<Producer<K,V>,? extends T> function)` Invokes the specified function on the Kafka `Producer` associated with this Sender.
`Mono<Void>`	`send(Publisher<ProducerRecord<K,V>> records)` Sends a sequence of producer records to Kafka.
`<T> Flux<SenderResult<T>>`	`send(Publisher<SenderRecord<K,V,T>> records, boolean delayError)` Sends a sequence of records to Kafka and returns a `Flux` of response record metadata including partition and offset of each send request.

- Method Detail
  - create
```
static <K,V> Sender<K,V> create(SenderOptions<K,V> options)
```
    Creates a Kafka sender that appends records to Kafka topic partitions.
    
    Parameters:
    
    options - Configuration options of this sender. Changes made to the options after the sender is created will not be used by the sender.
    
    Returns:
    
    new instance of Kafka sender
  - send
```
<T> Flux<SenderResult<T>> send(Publisher<SenderRecord<K,V,T>> records,
                               boolean delayError)
```
    Sends a sequence of records to Kafka and returns a Flux of response record metadata including partition and offset of each send request. Ordering of responses is guaranteed for partitions, but responses from different partitions may be interleaved in a different order from the requests. Additional correlation metadata may be passed through in the SenderRecord that is not sent to Kafka, but is included in the response Flux to enable matching responses to requests.
    Results are published when the send is acknowledged based on the acknowledgement mode configured using the option ProducerConfig.ACKS_CONFIG. If acks=0, records are acknowledged after the requests are buffered without waiting for any server acknowledgements. In this case the requests are not retried and the offset returned in SenderResult will be -1. For other ack modes, requests are retried up to the configured ProducerConfig.RETRIES_CONFIG times. If the request does not succeed after these attempts, the request fails and an exception indicating the reason for failure is returned in SenderResult.exception().
    Example usage:
```
 
     source = Flux.range(1, count)
                  .map(i -> SenderRecord.create(new ProducerRecord<>(topic, key(i), message(i)), i));
     sender.send(source, true)
           .doOnNext(r -> System.out.println("Message #" + r.correlationMetadata() + " metadata=" + r.recordMetadata()));
 
 
```
    Parameters:
    
    records - Outbound records along with additional correlation metadata to be included in response
    
    delayError - If false, send terminates when a response indicates failure, otherwise send is attempted for all records
    
    Returns:
    
    Flux of Kafka producer response record metadata along with the corresponding request correlation metadata. For records that could not be sent, the response contains an exception that indicates reason for failure.
  - send
```
Mono<Void> send(Publisher<ProducerRecord<K,V>> records)
```
    Sends a sequence of producer records to Kafka. No metadata is returned for individual producer records on success or failure. The returned Mono is failed immediately if a record cannot be delivered to Kafka after the configured number of retries in ProducerConfig.RETRIES_CONFIG.
    
    Parameters:
    
    records - Outbound producer records
    
    Returns:
    
    Mono that succeeds if all records are delivered successfully to Kafka and fails if any of the sends fail.
  - doOnProducer
```
<T> Mono<T> doOnProducer(Function<Producer<K,V>,? extends T> function)
```
    Invokes the specified function on the Kafka Producer associated with this Sender. The function is invoked when the returned Mono is subscribed to.
    Example usage:
```
 
     sender.doOnProducer(producer -> producer.partitionsFor(topic))
           .doOnSuccess(partitions -> System.out.println("Partitions " + partitions));
 
 
```
    Functions that are directly supported on the reactive Sender interface (eg. send) should not be invoked from function. The methods supported by doOnProducer are:
    Parameters:
    
    function - A function that takes Kafka Producer as parameter
    
    Returns:
    
    Mono that completes with the value returned by function
  - close
```
void close()
```
    Closes this sender and the underlying Kafka producer and releases all resources allocated to it.

Interface Sender<K,V>

Method Summary

Method Detail

create

send

send

doOnProducer

close