com.amazonaws.greengrass.streammanager.client

Class StreamManagerClientImpl

java.lang.Object

com.amazonaws.greengrass.streammanager.client.StreamManagerClientImpl

All Implemented Interfaces:

StreamManagerClient, AutoCloseable

public class StreamManagerClientImpl
extends Object
implements StreamManagerClient

StreamManagerClientImpl is a client that communicates with StreamManager server.

Method Summary

Modifier and Type	Method and Description
long	appendMessage(String stream, byte[] data) Append a message into the specified message stream.
void	close() Close the client socket.
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 class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

createMessageStream

public void createMessageStream(MessageStreamDefinition definition)
                         throws StreamManagerException

Create a message stream with a given definition.

Specified by:

createMessageStream in interface StreamManagerClient

Parameters:

definition - the message stream definition

Throws:

StreamManagerException - StreamManagerException

updateMessageStream

public 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)

Specified by:

updateMessageStream in interface StreamManagerClient

Parameters:

definition - the message stream definition

Throws:

StreamManagerException - StreamManagerException

deleteMessageStream

public void deleteMessageStream(String stream)
                         throws StreamManagerException

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

Specified by:

deleteMessageStream in interface StreamManagerClient

Parameters:

stream - stream name

Throws:

StreamManagerException - StreamManagerException

describeMessageStream

public MessageStreamInfo describeMessageStream(String stream)
                                        throws StreamManagerException

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

Specified by:

describeMessageStream in interface StreamManagerClient

Parameters:

stream - stream name

Returns:

MessageStreamInfo object containing information about the stream

Throws:

StreamManagerException - StreamManagerException

appendMessage

public 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.

Specified by:

appendMessage in interface StreamManagerClient

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

public 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.

Specified by:

readMessages in interface StreamManagerClient

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

public List<String> listStreams()
                         throws StreamManagerException

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

Specified by:

listStreams in interface StreamManagerClient

Returns:

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

Throws:

StreamManagerException - if any error is returned from the server.

close

public void close()

Close the client socket.

Specified by:

close in interface AutoCloseable