java.lang.Object
- com.networknt.kafka.common.FlinkKafkaProducer<K,V>

All Implemented Interfaces:

Closeable, AutoCloseable, org.apache.kafka.clients.producer.Producer<K,V>
```
public class FlinkKafkaProducer<K,V>
extends Object
implements org.apache.kafka.clients.producer.Producer<K,V>
```
Wrapper around KafkaProducer that allows to resume transactions in case of node failure, which allows to implement two phase commit algorithm for exactly-once semantic FlinkKafkaProducer.
For happy path usage is exactly the same as KafkaProducer. User is expected to call:
To actually implement two phase commit, it must be possible to always commit a transaction after pre-committing it (here, pre-commit is just a flush()). In case of some failure between flush() and commitTransaction() this class allows to resume interrupted transaction and commit if after a restart:
- initTransactions()
- beginTransaction()
- send(ProducerRecord)
- flush()
- getProducerId()
- getEpoch()
- node failure... restore producerId and epoch from state
- resumeTransaction(long, short)
- commitTransaction()
resumeTransaction(long, short) replaces initTransactions() as a way to obtain the producerId and epoch counters. It has to be done, because otherwise initTransactions() would automatically abort all on going transactions.
Second way this implementation differs from the reference KafkaProducer is that this one actually flushes new partitions on flush() instead of on commitTransaction().
The last one minor difference is that it allows to obtain the producerId and epoch counters via getProducerId() and getEpoch() methods (which are unfortunately private fields).
Those changes are compatible with Kafka's 0.11.0 REST API although it clearly was not the intention of the Kafka's API authors to make them possible.
Internally this implementation uses KafkaProducer and implements required changes via Java Reflection API. It might not be the prettiest solution. An alternative would be to re-implement whole Kafka's 0.11 REST API client on our own.

Constructor Summary

Constructors
Constructor Description

FlinkKafkaProducer(Map<String,Object> properties)

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`abortTransaction()`
`void`	`beginTransaction()`
`void`	`close()`
`void`	`close(Duration timeout)`
`void`	`commitTransaction()`
`void`	`flush()`
`short`	`getEpoch()`
`long`	`getProducerId()`
`String`	`getTransactionalId()`
`int`	`getTransactionCoordinatorId()`
`void`	`initTransactions()`
`Map<org.apache.kafka.common.MetricName,? extends org.apache.kafka.common.Metric>`	`metrics()`
`List<org.apache.kafka.common.PartitionInfo>`	`partitionsFor(String topic)`
`void`	`resumeTransaction(long producerId, short epoch)`	Instead of obtaining producerId and epoch from the transaction coordinator, re-use previously obtained ones, so that we can resume transaction after a restart.
`Future<org.apache.kafka.clients.producer.RecordMetadata>`	`send(org.apache.kafka.clients.producer.ProducerRecord<K,V> record)`
`Future<org.apache.kafka.clients.producer.RecordMetadata>`	`send(org.apache.kafka.clients.producer.ProducerRecord<K,V> record, org.apache.kafka.clients.producer.Callback callback)`
`void`	`sendOffsetsToTransaction(Map<org.apache.kafka.common.TopicPartition,org.apache.kafka.clients.consumer.OffsetAndMetadata> offsets, String consumerGroupId)`
`void`	`sendOffsetsToTransaction(Map<org.apache.kafka.common.TopicPartition,org.apache.kafka.clients.consumer.OffsetAndMetadata> offsets, org.apache.kafka.clients.consumer.ConsumerGroupMetadata groupMetadata)`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - FlinkKafkaProducer
```
public FlinkKafkaProducer(Map<String,Object> properties)
```
- Method Detail
  - initTransactions
```
public void initTransactions()
```
    Specified by:
    
    initTransactions in interface org.apache.kafka.clients.producer.Producer<K,V>
  - beginTransaction
```
public void beginTransaction()
                      throws org.apache.kafka.common.errors.ProducerFencedException
```
    Specified by:
    
    beginTransaction in interface org.apache.kafka.clients.producer.Producer<K,V>
    
    Throws:
    
    org.apache.kafka.common.errors.ProducerFencedException
  - commitTransaction
```
public void commitTransaction()
                       throws org.apache.kafka.common.errors.ProducerFencedException
```
    Specified by:
    
    commitTransaction in interface org.apache.kafka.clients.producer.Producer<K,V>
    
    Throws:
    
    org.apache.kafka.common.errors.ProducerFencedException
  - abortTransaction
```
public void abortTransaction()
                      throws org.apache.kafka.common.errors.ProducerFencedException
```
    Specified by:
    
    abortTransaction in interface org.apache.kafka.clients.producer.Producer<K,V>
    
    Throws:
    
    org.apache.kafka.common.errors.ProducerFencedException
  - sendOffsetsToTransaction
```
public void sendOffsetsToTransaction(Map<org.apache.kafka.common.TopicPartition,org.apache.kafka.clients.consumer.OffsetAndMetadata> offsets,
                                     String consumerGroupId)
                              throws org.apache.kafka.common.errors.ProducerFencedException
```
    Specified by:
    
    sendOffsetsToTransaction in interface org.apache.kafka.clients.producer.Producer<K,V>
    
    Throws:
    
    org.apache.kafka.common.errors.ProducerFencedException
  - sendOffsetsToTransaction
```
public void sendOffsetsToTransaction(Map<org.apache.kafka.common.TopicPartition,org.apache.kafka.clients.consumer.OffsetAndMetadata> offsets,
                                     org.apache.kafka.clients.consumer.ConsumerGroupMetadata groupMetadata)
                              throws org.apache.kafka.common.errors.ProducerFencedException
```
    Specified by:
    
    sendOffsetsToTransaction in interface org.apache.kafka.clients.producer.Producer<K,V>
    
    Throws:
    
    org.apache.kafka.common.errors.ProducerFencedException
  - send
```
public Future<org.apache.kafka.clients.producer.RecordMetadata> send(org.apache.kafka.clients.producer.ProducerRecord<K,V> record)
```
    Specified by:
    
    send in interface org.apache.kafka.clients.producer.Producer<K,V>
  - send
```
public Future<org.apache.kafka.clients.producer.RecordMetadata> send(org.apache.kafka.clients.producer.ProducerRecord<K,V> record,
                                                                     org.apache.kafka.clients.producer.Callback callback)
```
    Specified by:
    
    send in interface org.apache.kafka.clients.producer.Producer<K,V>
  - partitionsFor
```
public List<org.apache.kafka.common.PartitionInfo> partitionsFor(String topic)
```
    Specified by:
    
    partitionsFor in interface org.apache.kafka.clients.producer.Producer<K,V>
  - metrics
```
public Map<org.apache.kafka.common.MetricName,? extends org.apache.kafka.common.Metric> metrics()
```
    Specified by:
    
    metrics in interface org.apache.kafka.clients.producer.Producer<K,V>
  - close
```
public void close()
```
    Specified by:
    
    close in interface AutoCloseable
    
    Specified by:
    
    close in interface Closeable
    
    Specified by:
    
    close in interface org.apache.kafka.clients.producer.Producer<K,V>
  - close
```
public void close(Duration timeout)
```
    Specified by:
    
    close in interface org.apache.kafka.clients.producer.Producer<K,V>
  - flush
```
public void flush()
```
    Specified by:
    
    flush in interface org.apache.kafka.clients.producer.Producer<K,V>
  - resumeTransaction
```
public void resumeTransaction(long producerId,
                              short epoch)
```
    Instead of obtaining producerId and epoch from the transaction coordinator, re-use previously obtained ones, so that we can resume transaction after a restart. Implementation of this method is based on KafkaProducer.initTransactions().
    
    Parameters:
    
    producerId - producer id
    
    epoch - epoch
  - getTransactionalId
```
public String getTransactionalId()
```
  - getProducerId
```
public long getProducerId()
```
  - getEpoch
```
public short getEpoch()
```
  - getTransactionCoordinatorId
```
public int getTransactionCoordinatorId()
```

Class FlinkKafkaProducer<K,​V>

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

FlinkKafkaProducer

Method Detail

initTransactions

beginTransaction

commitTransaction

abortTransaction

sendOffsetsToTransaction

sendOffsetsToTransaction

send

send

partitionsFor

metrics

close

close

flush

resumeTransaction

getTransactionalId

getProducerId

getEpoch

getTransactionCoordinatorId

Class FlinkKafkaProducer<K,V>