io.nats.client

Interface BaseConsumerContext

All Known Subinterfaces:

ConsumerContext, OrderedConsumerContext

public interface BaseConsumerContext

The Consumer Context provides a convenient interface around a defined JetStream Consumer

Note: ConsumerContext requires a pull consumer.

Method Summary

Modifier and Type	Method and Description
@NonNull MessageConsumer	consume(@NonNull ConsumeOptions consumeOptions, @Nullable Dispatcher dispatcher, @NonNull MessageHandler handler) Start a long-running MessageConsumer with custom ConsumeOptions.
@NonNull MessageConsumer	consume(@NonNull ConsumeOptions consumeOptions, @NonNull MessageHandler handler) Start a long-running MessageConsumer with custom ConsumeOptions.
@NonNull MessageConsumer	consume(@Nullable Dispatcher dispatcher, @NonNull MessageHandler handler) Start a long-running MessageConsumer with default ConsumeOptions.
@NonNull MessageConsumer	consume(@NonNull MessageHandler handler) Start a long-running MessageConsumer with default ConsumeOptions.
@NonNull FetchConsumer	fetch(@NonNull FetchConsumeOptions fetchConsumeOptions) Start a one-use Fetch Consumer with custom FetchConsumeOptions.
@NonNull FetchConsumer	fetchBytes(int maxBytes) Start a one use Fetch Consumer using all defaults other than the number of bytes.
@NonNull FetchConsumer	fetchMessages(int maxMessages) Start a one use Fetch Consumer using all defaults other than the number of messages.
@Nullable java.lang.String	getConsumerName() Gets the consumer name that was used to create the context.
@NonNull IterableConsumer	iterate() Start a long-running IterableConsumer with default ConsumeOptions.
@NonNull IterableConsumer	iterate(@NonNull ConsumeOptions consumeOptions) Start a long-running IterableConsumer with custom ConsumeOptions.
@Nullable Message	next() Read the next message with max wait set to ms
@Nullable Message	next(@Nullable java.time.Duration maxWait) Read the next message with provided max wait
@Nullable Message	next(long maxWaitMillis) Read the next message with provided max wait
boolean	unpin(java.lang.String group) Unpins this consumer

Method Detail

getConsumerName

@Nullable java.lang.String getConsumerName()

Gets the consumer name that was used to create the context. Some implementations do not guarantee that the name is available.

Returns:

the consumer name

next

@Nullable Message next()
                throws java.io.IOException,
                       java.lang.InterruptedException,
                       JetStreamStatusCheckedException,
                       JetStreamApiException

Read the next message with max wait set to ms

Returns:

the next message or null if the max wait expires

Throws:

java.io.IOException - covers various communication issues with the NATS server, such as timeout or interruption

java.lang.InterruptedException - if one is thrown, to propagate it up

JetStreamStatusCheckedException - an exception representing a status that requires attention, such as the consumer was deleted on the server in the middle of use.

JetStreamApiException - the request had an error related to the data

next

@Nullable Message next(@Nullable java.time.Duration maxWait)
                throws java.io.IOException,
                       java.lang.InterruptedException,
                       JetStreamStatusCheckedException,
                       JetStreamApiException

Read the next message with provided max wait

Parameters:

maxWait - duration of max wait. If null, zero or negative, will be used. If greater than zero, it cannot be less than milliseconds.

Returns:

the next message or null if the max wait expires

Throws:

java.io.IOException - covers various communication issues with the NATS server, such as timeout or interruption

java.lang.InterruptedException - if one is thrown, to propagate it up

JetStreamStatusCheckedException - an exception representing a status that requires attention, such as the consumer was deleted on the server in the middle of use.

JetStreamApiException - the request had an error related to the data

java.lang.IllegalArgumentException - if maxWait is provided and less than

next

@Nullable Message next(long maxWaitMillis)
                throws java.io.IOException,
                       java.lang.InterruptedException,
                       JetStreamStatusCheckedException,
                       JetStreamApiException

Read the next message with provided max wait

Parameters:

maxWaitMillis - the max wait value in milliseconds. Cannot be less than milliseconds.

Returns:

the next message or null if the max wait expires

Throws:

java.io.IOException - covers various communication issues with the NATS server, such as timeout or interruption

java.lang.InterruptedException - if one is thrown, to propagate it up

JetStreamStatusCheckedException - an exception representing a status that requires attention, such as the consumer was deleted on the server in the middle of use.

JetStreamApiException - the request had an error related to the data

java.lang.IllegalArgumentException - if maxWait is provided and less than

fetchMessages

@NonNull FetchConsumer fetchMessages(int maxMessages)
                              throws java.io.IOException,
                                     JetStreamApiException

Start a one use Fetch Consumer using all defaults other than the number of messages. See FetchConsumer

Parameters:

maxMessages - the maximum number of messages to consume

Returns:

the FetchConsumer instance

Throws:

java.io.IOException - covers various communication issues with the NATS server, such as timeout or interruption

JetStreamApiException - the request had an error related to the data

fetchBytes

@NonNull FetchConsumer fetchBytes(int maxBytes)
                           throws java.io.IOException,
                                  JetStreamApiException

Start a one use Fetch Consumer using all defaults other than the number of bytes. See FetchConsumer

Parameters:

maxBytes - the maximum number of bytes to consume

Returns:

the FetchConsumer instance

Throws:

java.io.IOException - covers various communication issues with the NATS server, such as timeout or interruption

JetStreamApiException - the request had an error related to the data

fetch

@NonNull FetchConsumer fetch(@NonNull FetchConsumeOptions fetchConsumeOptions)
                      throws java.io.IOException,
                             JetStreamApiException

Start a one-use Fetch Consumer with custom FetchConsumeOptions. See FetchConsumeOptions

Parameters:

fetchConsumeOptions - the custom fetch consume options.

Returns:

the FetchConsumer instance

Throws:

java.io.IOException - covers various communication issues with the NATS server, such as timeout or interruption

JetStreamApiException - the request had an error related to the data

iterate

@NonNull IterableConsumer iterate()
                           throws java.io.IOException,
                                  JetStreamApiException

Start a long-running IterableConsumer with default ConsumeOptions. See IterableConsumer and ConsumeOptions IterableConsumer require the developer calls nextMessage.

Returns:

the IterableConsumer instance

Throws:

java.io.IOException - covers various communication issues with the NATS server, such as timeout or interruption

JetStreamApiException - the request had an error related to the data

iterate

@NonNull IterableConsumer iterate(@NonNull ConsumeOptions consumeOptions)
                           throws java.io.IOException,
                                  JetStreamApiException

Start a long-running IterableConsumer with custom ConsumeOptions. See IterableConsumer and ConsumeOptions IterableConsumer requires the developer calls nextMessage.

Parameters:

consumeOptions - the custom consume options

Returns:

the IterableConsumer instance

Throws:

java.io.IOException - covers various communication issues with the NATS server, such as timeout or interruption

JetStreamApiException - the request had an error related to the data

consume

@NonNull MessageConsumer consume(@NonNull MessageHandler handler)
                          throws java.io.IOException,
                                 JetStreamApiException

Start a long-running MessageConsumer with default ConsumeOptions. See MessageConsumer and ConsumeOptions and the default dispatcher for this consumer context.

Parameters:

handler - the MessageHandler used for receiving messages.

Returns:

the MessageConsumer instance

Throws:

java.io.IOException - covers various communication issues with the NATS server, such as timeout or interruption

JetStreamApiException - the request had an error related to the data

consume

@NonNull MessageConsumer consume(@Nullable Dispatcher dispatcher,
                                 @NonNull MessageHandler handler)
                          throws java.io.IOException,
                                 JetStreamApiException

Start a long-running MessageConsumer with default ConsumeOptions. See MessageConsumer and ConsumeOptions

Parameters:

dispatcher - The dispatcher to handle this subscription. If null, the default dispatcher will be used.

handler - the MessageHandler used for receiving messages.

Returns:

the MessageConsumer instance

Throws:

java.io.IOException - covers various communication issues with the NATS server, such as timeout or interruption

JetStreamApiException - the request had an error related to the data

consume

@NonNull MessageConsumer consume(@NonNull ConsumeOptions consumeOptions,
                                 @NonNull MessageHandler handler)
                          throws java.io.IOException,
                                 JetStreamApiException

Start a long-running MessageConsumer with custom ConsumeOptions. See MessageConsumer and ConsumeOptions and the default dispatcher for this consumer context.

Parameters:

consumeOptions - the custom consume options

handler - the MessageHandler used for receiving messages.

Returns:

the MessageConsumer instance

Throws:

java.io.IOException - covers various communication issues with the NATS server, such as timeout or interruption

JetStreamApiException - the request had an error related to the data

consume

@NonNull MessageConsumer consume(@NonNull ConsumeOptions consumeOptions,
                                 @Nullable Dispatcher dispatcher,
                                 @NonNull MessageHandler handler)
                          throws java.io.IOException,
                                 JetStreamApiException

Start a long-running MessageConsumer with custom ConsumeOptions. See MessageConsumer and ConsumeOptions

Parameters:

consumeOptions - the custom consume options

dispatcher - The dispatcher to handle this subscription. If null, the default dispatcher will be used.

handler - the MessageHandler used for receiving messages.

Returns:

the MessageConsumer instance

Throws:

java.io.IOException - covers various communication issues with the NATS server, such as timeout or interruption

JetStreamApiException - the request had an error related to the data

unpin

boolean unpin(java.lang.String group)
       throws java.io.IOException,
              JetStreamApiException

Unpins this consumer

Parameters:

group - the group name of the consumer's group

Returns:

true if the delete succeeded

Throws:

java.io.IOException - covers various communication issues with the NATS server such as timeout or interruption

JetStreamApiException - the request had an error related to the data