All Implemented Interfaces:


public final class JetStreamMessage<T extends Object>

Wrapper for JetStream messages with acknowledgment controls

Provides type-safe access to message payload and metadata, along with coroutine-friendly acknowledgment operations.

Example usage:

js.subscribe<OrderEvent>(stream = "ORDERS", filterSubject = "orders.*").collect { msg ->
    try {
        processOrder(msg.payload)
        msg.ack()
    } catch (e: Exception) {
        if (msg.delivered >= 3) {
            msg.term() // Terminal failure after 3 attempts
        } else {
            msg.nak(delay = 5.seconds) // Retry with backoff
        }
    }
}

Nested Class Summary

Nested Classes
Modifier and Type	Class	Description

Field Summary

Fields
Modifier and Type	Field	Description
`private final T`	`payload`
`private final String`	`subject`
`private final String`	`stream`
`private final String`	`consumer`
`private final Long`	`delivered`
`private final Long`	`streamSequence`
`private final Long`	`consumerSequence`
`private final Instant`	`timestamp`
`private final Headers`	`headers`
`private final Long`	`pendingCount`

Constructor Summary

Constructors
Constructor	Description
`JetStreamMessage(T payload, String subject, String stream, String consumer, Long delivered, Long streamSequence, Long consumerSequence, Instant timestamp, Headers headers, Long pendingCount, Message msg)`

Enum Constant Summary

Enum Constants
Enum Constant	Description

Method Summary

Modifier and Type	Method	Description
`final T`	`getPayload()`	The decoded message payload
`final String`	`getSubject()`	The NATS subject the message was published to
`final String`	`getStream()`	The JetStream stream name
`final String`	`getConsumer()`	The consumer name (null for ephemeral consumers without explicit names)
`final Long`	`getDelivered()`	Number of times this message has been delivered
`final Long`	`getStreamSequence()`	Sequence number in the stream
`final Long`	`getConsumerSequence()`	Sequence number for this consumer
`final Instant`	`getTimestamp()`	When the message was originally published
`final Headers`	`getHeaders()`	Optional NATS headers attached to the message
`final Long`	`getPendingCount()`	Number of messages pending for this consumer (0 if unknown)
`final Unit`	`ack()`	Acknowledge successful processing of the messageTells JetStream that the message has been successfully processed and should not be redelivered.
`final Unit`	`nak(Duration delay)`	Negatively acknowledge the message (request redelivery)Tells JetStream that processing failed and the message should be redelivered.
`final Unit`	`term()`	Terminate processing of the messageTells JetStream that the message cannot be processed and should not be redelivered, regardless of maxDeliver setting.
`final Unit`	`inProgress()`	Signal that processing is still in progressExtends the acknowledgment deadline for long-running message processing.
`final Boolean`	`isRedelivered()`	Check if this message is a redelivery
`final Long`	`remainingDeliveries(Long maxDeliver)`	Calculate remaining delivery attempts
`final Boolean`	`hasPending()`	Check if this message has more pending messages after it
`String`	`toString()`

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

- Constructor Detail
  - JetStreamMessage
```
JetStreamMessage(T payload, String subject, String stream, String consumer, Long delivered, Long streamSequence, Long consumerSequence, Instant timestamp, Headers headers, Long pendingCount, Message msg)
```
- Method Detail
  - getPayload
```
 final T getPayload()
```
    The decoded message payload
  - getSubject
```
 final String getSubject()
```
    The NATS subject the message was published to
  - getStream
```
 final String getStream()
```
    The JetStream stream name
  - getConsumer
```
 final String getConsumer()
```
    The consumer name (null for ephemeral consumers without explicit names)
  - getDelivered
```
 final Long getDelivered()
```
    Number of times this message has been delivered
  - getStreamSequence
```
 final Long getStreamSequence()
```
    Sequence number in the stream
  - getConsumerSequence
```
 final Long getConsumerSequence()
```
    Sequence number for this consumer
  - getTimestamp
```
 final Instant getTimestamp()
```
    When the message was originally published
  - getHeaders
```
 final Headers getHeaders()
```
    Optional NATS headers attached to the message
  - getPendingCount
```
 final Long getPendingCount()
```
    Number of messages pending for this consumer (0 if unknown)
  - ack
```
 final Unit ack()
```
    Acknowledge successful processing of the message
    Tells JetStream that the message has been successfully processed and should not be redelivered. This is the standard acknowledgment for successful processing.
    Thread-safe, and it does not wait for the server: the acknowledgement goes onto the connection's outgoing queue exactly as a publish does - including what happens when that queue is full, see eu.vstoyanov.natsy.NatsKlient.publishBytes. No I/O dispatcher needed. This operation is also idempotent - calling it multiple times on the same message is safe (though subsequent calls will have no effect).
  - nak
```
 final Unit nak(Duration delay)
```
    Negatively acknowledge the message (request redelivery)
    Tells JetStream that processing failed and the message should be redelivered. Optionally specify a delay before redelivery to implement backoff strategies.
    If the message has already been delivered the maximum number of times (as configured by maxDeliver), it will not be redelivered again.
    Thread-safe, and it does not wait for the server: the negative acknowledgement goes onto the connection's outgoing queue exactly as a publish does - including what happens when that queue is full, see eu.vstoyanov.natsy.NatsKlient.publishBytes. No I/O dispatcher needed.
    
    Parameters:
    
    delay - Optional delay before redelivery (null for immediate redelivery)
  - term
```
 final Unit term()
```
    Terminate processing of the message
    Tells JetStream that the message cannot be processed and should not be redelivered, regardless of maxDeliver setting. Use this for messages that are malformed or will never be processable.
    This is different from ack() in that it indicates failure rather than success, which can be useful for monitoring and alerting.
    Thread-safe, and it does not wait for the server: the termination goes onto the connection's outgoing queue exactly as a publish does - including what happens when that queue is full, see eu.vstoyanov.natsy.NatsKlient.publishBytes. No I/O dispatcher needed.
  - inProgress
```
 final Unit inProgress()
```
    Signal that processing is still in progress
    Extends the acknowledgment deadline for long-running message processing. Call this periodically during processing to prevent the message from being redelivered due to ackWait timeout.
    Typically used in a loop for operations that take longer than the configured ackWait duration.
    Thread-safe, and it does not wait for the server: the in-progress signal goes onto the connection's outgoing queue exactly as a publish does - including what happens when that queue is full, see eu.vstoyanov.natsy.NatsKlient.publishBytes. No I/O dispatcher needed.
  - isRedelivered
```
 final Boolean isRedelivered()
```
    Check if this message is a redelivery
    
    Returns:
    
    true if the message has been delivered more than once
  - remainingDeliveries
```
 final Long remainingDeliveries(Long maxDeliver)
```
    Calculate remaining delivery attempts
    
    Parameters:
    
    maxDeliver - The maximum delivery count configured for the consumer
    
    Returns:
    
    Number of remaining delivery attempts, or -1 if unlimited
  - hasPending
```
 final Boolean hasPending()
```
    Check if this message has more pending messages after it
    
    Returns:
    
    true if there are messages pending for delivery
  - toString
```
 String toString()
```

Class JetStreamMessage

Nested Class Summary

Field Summary

Constructor Summary

Enum Constant Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

JetStreamMessage

Method Detail

getPayload

getSubject

getStream

getConsumer

getDelivered

getStreamSequence

getConsumerSequence

getTimestamp

getHeaders

getPendingCount

ack

nak

term

inProgress

isRedelivered

remainingDeliveries

hasPending

toString