Package org.apache.kafka.streams.processor.api

Class Record<K,V>

java.lang.Object
org.apache.kafka.streams.processor.api.Record<K,V>
Type Parameters:
K - The type of the key
V - The type of the value
public class Record<K,V> extends Object
A data class representing an incoming record for processing in a Processor or a record to forward to downstream processors via ProcessorContext. This class encapsulates all the data attributes of a record: the key and value, but also the timestamp of the record and any record headers. This class is immutable, though the objects referenced in the attributes of this class may themselves be mutable.

  • Constructor Summary

    Constructors
    Constructor
    Description
    Record(K key, V value, long timestamp)
    Convenience constructor in case you do not wish to specify any headers.
    Record(K key, V value, long timestamp, Headers headers)
    The full constructor, specifying all the attributes of the record.

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    equals(Object o)
     
    int
    hashCode()
     
    Headers
    headers()
    The headers of the record.
    K
    key()
    The key of the record.
    long
    timestamp()
    The timestamp of the record.
    String
    toString()
     
    V
    value()
    The value of the record.
    Record<K,V>
    withHeaders(Headers headers)
    A convenient way to produce a new record if you only need to change the headers.
    <NewK> Record<NewK,V>
    withKey(NewK key)
    A convenient way to produce a new record if you only need to change the key.
    Record<K,V>
    withTimestamp(long timestamp)
    A convenient way to produce a new record if you only need to change the timestamp.
    <NewV> Record<K,NewV>
    withValue(NewV value)
    A convenient way to produce a new record if you only need to change the value.

    Methods inherited from class java.lang.Object

    clone, finalize, getClass, notify, notifyAll, wait, wait, wait

  • Constructor Details

    • Record

      public Record(K key, V value, long timestamp, Headers headers)
      The full constructor, specifying all the attributes of the record. Note: this constructor makes a copy of the headers argument. See ProcessorContext.forward(Record) for considerations around mutability of keys, values, and headers.
      Parameters:
      key - The key of the record. May be null.
      value - The value of the record. May be null.
      timestamp - The timestamp of the record. May not be negative.
      headers - The headers of the record. May be null, which will cause subsequent calls to headers() to return a non-null, empty, Headers collection.
      Throws:
      IllegalArgumentException - if the timestamp is negative.
      See Also:

    • Record

      public Record(K key, V value, long timestamp)
      Convenience constructor in case you do not wish to specify any headers. Subsequent calls to headers() will return a non-null, empty, Headers collection.
      Parameters:
      key - The key of the record. May be null.
      value - The value of the record. May be null.
      timestamp - The timestamp of the record. May not be negative.
      Throws:
      IllegalArgumentException - if the timestamp is negative.

  • Method Details

    • key

      public K key()
      The key of the record. May be null.

    • value

      public V value()
      The value of the record. May be null.

    • timestamp

      public long timestamp()
      The timestamp of the record. Will never be negative.

    • headers

      public Headers headers()
      The headers of the record. Never null.

    • withKey

      public <NewK> Record<NewK,V> withKey(NewK key)
      A convenient way to produce a new record if you only need to change the key. Copies the attributes of this record with the key replaced.
      Type Parameters:
      NewK - The type of the new record's key.
      Parameters:
      key - The key of the result record. May be null.
      Returns:
      A new Record instance with all the same attributes (except that the key is replaced).

    • withValue

      public <NewV> Record<K,NewV> withValue(NewV value)
      A convenient way to produce a new record if you only need to change the value. Copies the attributes of this record with the value replaced.
      Type Parameters:
      NewV - The type of the new record's value.
      Parameters:
      value - The value of the result record.
      Returns:
      A new Record instance with all the same attributes (except that the value is replaced).

    • withTimestamp

      public Record<K,V> withTimestamp(long timestamp)
      A convenient way to produce a new record if you only need to change the timestamp. Copies the attributes of this record with the timestamp replaced.
      Parameters:
      timestamp - The timestamp of the result record.
      Returns:
      A new Record instance with all the same attributes (except that the timestamp is replaced).

    • withHeaders

      public Record<K,V> withHeaders(Headers headers)
      A convenient way to produce a new record if you only need to change the headers. Copies the attributes of this record with the headers replaced. Also makes a copy of the provided headers. See ProcessorContext.forward(Record) for considerations around mutability of keys, values, and headers.
      Parameters:
      headers - The headers of the result record.
      Returns:
      A new Record instance with all the same attributes (except that the headers are replaced).

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • equals

      public boolean equals(Object o)
      Overrides:
      equals in class Object

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object