Message (NATS.IO Java API)

```
public interface Message
```
The NATS library uses a Message object to encapsulate incoming messages. Applications publish and send requests with raw strings and byte[] but incoming messages can have a few values, so they need a wrapper.
The byte[] returned by getData() is not shared with any library code and is safe to manipulate. NOTICE: This interface is intended only to be implemented internally, although since it is public it is technically available to anyone and breaking changes should be avoided. For instance: - Signatures should not be changed. - If methods are added, a default implementation should be provided.

Method Summary

All Methods Instance Methods Abstract Methods Default Methods Deprecated Methods
Modifier and Type	Method and Description
`void`	`ack()` ack acknowledges a JetStream messages received from a Consumer, indicating the message should not be received again later.
`void`	`ackSync(java.time.Duration timeout)` ack acknowledges a JetStream messages received from a Consumer, indicating the message should not be received again later.
`default long`	`consumeByteCount()` The number of bytes the server counts for the message when calculating byte counts.
`Connection`	`getConnection()` the connection which can be used for publishing, will be null if the subscription is null
`byte[]`	`getData()` the data from the message
`io.nats.client.impl.Headers`	`getHeaders()` the headers object for the message
`java.lang.String`	`getReplyTo()` the subject the application is expected to send a reply message on
`java.lang.String`	`getSID()` the id associated with the subscription, used by the connection when processing an incoming message from the server
`io.nats.client.support.Status`	`getStatus()` the status object message if this is a status message
`java.lang.String`	`getSubject()` the subject that this message was sent to
`Subscription`	`getSubscription()` the Subscription associated with this message, may be owned by a Dispatcher
`boolean`	`hasHeaders()` true if there are headers
`void`	`inProgress()` Indicates that this message is being worked on and reset redelivery timer in the server.
`boolean`	`isJetStream()` Checks if a message is from JetStream or is a standard message.
`boolean`	`isStatusMessage()` true if there is status
`boolean`	`isUtf8mode()` Deprecated. because the mode doesn't matter if is utf8Mode
`io.nats.client.impl.AckType`	`lastAck()` the last ack that was done with this message the last ack or null
`io.nats.client.impl.NatsJetStreamMetaData`	`metaData()` Gets the metadata associated with a JetStream message.
`void`	`nak()` nak acknowledges a JetStream message has been received but indicates that the message is not completely processed and should be sent again later.
`void`	`nakWithDelay(java.time.Duration nakDelay)` nak acknowledges a JetStream message has been received but indicates that the message is not completely processed and should be sent again later, after at least the delay amount.
`void`	`nakWithDelay(long nakDelayMillis)` nak acknowledges a JetStream message has been received but indicates that the message is not completely processed and should be sent again later, after at least the delay amount.
`void`	`term()` term instructs the server to stop redelivery of this message without acknowledging it as successfully processed.

- Method Detail
  - getSubject
```
java.lang.String getSubject()
```
    the subject that this message was sent to
    
    Returns:
    
    the subject
  - getReplyTo
```
java.lang.String getReplyTo()
```
    the subject the application is expected to send a reply message on
    
    Returns:
    
    the reply to
  - hasHeaders
```
boolean hasHeaders()
```
    true if there are headers
    
    Returns:
    
    the flag
  - getHeaders
```
io.nats.client.impl.Headers getHeaders()
```
    the headers object for the message
    
    Returns:
    
    the headers
  - isStatusMessage
```
boolean isStatusMessage()
```
    true if there is status
    
    Returns:
    
    the flag
  - getStatus
```
io.nats.client.support.Status getStatus()
```
    the status object message if this is a status message
    
    Returns:
    
    the status object
  - getData
```
byte[] getData()
```
    the data from the message
    
    Returns:
    
    the data
  - isUtf8mode
```
@Deprecated
boolean isUtf8mode()
```
    Deprecated. because the mode doesn't matter if is utf8Mode
    
    Returns:
    
    always false
  - getSubscription
```
Subscription getSubscription()
```
    the Subscription associated with this message, may be owned by a Dispatcher
    
    Returns:
    
    the subscription
  - getSID
```
java.lang.String getSID()
```
    the id associated with the subscription, used by the connection when processing an incoming message from the server
    
    Returns:
    
    the SID
  - getConnection
```
Connection getConnection()
```
    the connection which can be used for publishing, will be null if the subscription is null
    
    Returns:
    
    the connection
  - metaData
```
io.nats.client.impl.NatsJetStreamMetaData metaData()
```
    Gets the metadata associated with a JetStream message. metadata or null if the message is not a JetStream message.
    
    Returns:
    
    the metadata
  - lastAck
```
io.nats.client.impl.AckType lastAck()
```
    the last ack that was done with this message the last ack or null
    
    Returns:
    
    the last ack
  - ack
```
void ack()
```
    ack acknowledges a JetStream messages received from a Consumer, indicating the message should not be received again later.
  - ackSync
```
void ackSync(java.time.Duration timeout)
      throws java.util.concurrent.TimeoutException,
             java.lang.InterruptedException
```
    ack acknowledges a JetStream messages received from a Consumer, indicating the message should not be received again later. Duration.ZERO does not confirm the acknowledgement.
    
    Parameters:
    
    timeout - the duration to wait for an ack confirmation
    
    Throws:
    
    java.util.concurrent.TimeoutException - if a timeout was specified and the NATS server does not return a response
    
    java.lang.InterruptedException - if the thread is interrupted
  - nak
```
void nak()
```
    nak acknowledges a JetStream message has been received but indicates that the message is not completely processed and should be sent again later.
  - nakWithDelay
```
void nakWithDelay(java.time.Duration nakDelay)
```
    nak acknowledges a JetStream message has been received but indicates that the message is not completely processed and should be sent again later, after at least the delay amount.
    
    Parameters:
    
    nakDelay - tell the server how long to delay before processing the ack
  - nakWithDelay
```
void nakWithDelay(long nakDelayMillis)
```
    nak acknowledges a JetStream message has been received but indicates that the message is not completely processed and should be sent again later, after at least the delay amount.
    
    Parameters:
    
    nakDelayMillis - tell the server how long to delay before processing the ack
  - term
```
void term()
```
    term instructs the server to stop redelivery of this message without acknowledging it as successfully processed.
  - inProgress
```
void inProgress()
```
    Indicates that this message is being worked on and reset redelivery timer in the server.
  - isJetStream
```
boolean isJetStream()
```
    Checks if a message is from JetStream or is a standard message.
    
    Returns:
    
    true if the message is from JetStream.
  - consumeByteCount
```
default long consumeByteCount()
```
    The number of bytes the server counts for the message when calculating byte counts. Only applies to JetStream messages received from the server.
    
    Returns:
    
    the consumption byte count or -1 if the message implementation does not support this method

Interface Message

Method Summary

Method Detail

getSubject

getReplyTo

hasHeaders

getHeaders

isStatusMessage

getStatus

getData

isUtf8mode

getSubscription

getSID

getConnection

metaData

lastAck

ack

ackSync

nak

nakWithDelay

nakWithDelay

term

inProgress

isJetStream

consumeByteCount