com.amazonaws.greengrass.streammanager.client

Interface StreamManagerClient

All Superinterfaces:

AutoCloseable

All Known Implementing Classes:

StreamManagerClientImpl

public interface StreamManagerClient
extends AutoCloseable

Method Summary

Modifier and Type	Method and Description
long	appendMessage(String stream, byte[] data) Append a message into the specified message stream.
void	createMessageStream(MessageStreamDefinition definition) Create a message stream with a given definition.
void	deleteMessageStream(String stream) Delete a message stream, including the data.
MessageStreamInfo	describeMessageStream(String stream) Describe a message stream to get metadata including the stream's definition, size, and exporter statuses.
List<String>	listStreams() List the streams in StreamManager.
List<Message>	readMessages(String stream, ReadMessagesOptions options) Read message(s) from a chosen stream with options.
void	updateMessageStream(MessageStreamDefinition definition) Updates a message stream with a given definition.

Methods inherited from interface java.lang.AutoCloseable

close

Method Detail

createMessageStream

void createMessageStream(MessageStreamDefinition definition)
                  throws StreamManagerException

Create a message stream with a given definition.

Parameters:

definition - the message stream definition

Throws:

StreamManagerException - StreamManagerException

updateMessageStream

void updateMessageStream(MessageStreamDefinition definition)
                  throws StreamManagerException

Updates a message stream with a given definition. Minimum version requirements: StreamManager server version 1.1 (or AWS IoT Greengrass Core 1.11.0)

Parameters:

definition - the message stream definition

Throws:

StreamManagerException - StreamManagerException

deleteMessageStream

void deleteMessageStream(String stream)
                  throws StreamManagerException

Delete a message stream, including the data. Deleting a stream will stop all ongoing exports.

Parameters:

stream - stream name

Throws:

StreamManagerException - StreamManagerException

describeMessageStream

MessageStreamInfo describeMessageStream(String stream)
                                 throws StreamManagerException

Describe a message stream to get metadata including the stream's definition, size, and exporter statuses.

Parameters:

stream - stream name

Returns:

MessageStreamInfo object containing information about the stream

Throws:

StreamManagerException - StreamManagerException

appendMessage

long appendMessage(String stream,
                   byte[] data)
            throws StreamManagerException

Append a message into the specified message stream. Returns the sequence number of the message if it was successfully appended.

Parameters:

stream - The name of the stream.

data - The binary payload of the message.

Returns:

the sequence number of the appended message.

Throws:

StreamManagerException - StreamManagerException

readMessages

List<Message> readMessages(String stream,
                           ReadMessagesOptions options)
                    throws StreamManagerException

Read message(s) from a chosen stream with options. If no options are specified it will try to read 1 message from the stream.

Default options used when reading from the stream: desiredStartSequenceNumber: 0, minMessageCount: 1, maxMessageCount: 1, readTimeoutMillis: 0 // Where 0 here represents that the server will immediately return the messages // or an exception if there were not enough messages available.

If desiredStartSequenceNumber is specified in the options and is less than the current beginning of the stream, returned messages will start at the beginning of the stream and not necessarily the desiredStartSequenceNumber.

Parameters:

stream - the name of the stream.

options - the options of readMessages() operation.

Returns:

a list of messages. empty if there is no message to read.

Throws:

StreamManagerException - if any error is returned from the server

listStreams

List<String> listStreams()
                  throws StreamManagerException

List the streams in StreamManager. Returns a list of their names.

Returns:

a list of stream names. empty if there are no streams.

Throws:

StreamManagerException - if any error is returned from the server.