Package markets.alpaca.client.ws

Class AlpacaTradingStream

java.lang.Object

markets.alpaca.client.ws.internal.AbstractAlpacaStream

markets.alpaca.client.ws.AlpacaTradingStream

All Implemented Interfaces:

AutoCloseable

public final class AlpacaTradingStream
extends AbstractAlpacaStream

WebSocket client for the Alpaca real-time trading stream (/stream).

Provides real-time order lifecycle events (trade_updates) for the authenticated brokerage account. The trading stream uses a different wire protocol than the market data streams: authentication uses action: authenticate with credentials nested under data, and subscriptions use action: listen.

Usage

 var stream = AlpacaClientFactory.tradingStream(
     creds,
     TradingEnvironment.PAPER,
     new TradingStreamListener() {
         @Override public void onAuthenticated() {
             // subscribe to trade updates right after auth
         }
         @Override public void onTradeUpdate(TradeUpdate u) { System.out.println(u); }
     });

 stream.connect(TradingSubscription.TRADE_UPDATES);
 

The client reconnects with jittered exponential backoff and re-listens to the previously active streams after re-authentication.

Callbacks are dispatched on OkHttp's reader thread by default. Use the overloads that accept an Executor to offload listener work. The paper endpoint sends binary frames, which are transparently decoded as UTF-8 text.

Constructor Summary

Constructors

Constructor	Description
AlpacaTradingStream(okhttp3.OkHttpClient httpClient, AlpacaCredentials credentials, String url, TradingStreamListener listener)	Creates a new trading stream client for a custom WebSocket URL.
AlpacaTradingStream(okhttp3.OkHttpClient httpClient, AlpacaCredentials credentials, TradingEnvironment environment, TradingStreamListener listener)	Creates a new trading stream client.
AlpacaTradingStream(okhttp3.OkHttpClient httpClient, AlpacaCredentials credentials, TradingEnvironment environment, TradingStreamListener listener, AlpacaStreamReconnectPolicy reconnectPolicy)	Creates a new trading stream client with a custom reconnect policy.
AlpacaTradingStream(okhttp3.OkHttpClient httpClient, AlpacaCredentials credentials, TradingEnvironment environment, TradingStreamListener listener, AlpacaStreamReconnectPolicy reconnectPolicy, Executor callbackExecutor)	Creates a new trading stream client with a custom reconnect policy and listener executor.

Method Summary

Modifier and Type	Method	Description
protected okhttp3.Request	buildRequest()	Builds the WebSocket upgrade request (URL + any auth headers).
void	connect(TradingSubscription subscription)	Opens the stream and starts listening after authentication completes.
protected void	handleClose(int code, String reason, boolean willReconnect)	Called when the connection closes, either cleanly or due to an error.
protected void	handleOpen(okhttp3.WebSocket ws)	Called when the WebSocket connection is open.
protected void	handleText(okhttp3.WebSocket ws, String text)	Called for each text frame received from the server.
void	listen(TradingSubscription subscription)	Subscribes to (or replaces) the active set of trading streams.
protected void	notifyReconnecting(int attempt)	Called just before a reconnect attempt is initiated.

Methods inherited from class markets.alpaca.client.ws.internal.AbstractAlpacaStream

authenticationFuture, authenticationResultFuture, close, closeTerminal, closeTerminal, completeAuthentication, completeAuthentication, connect, handleBytes, invokeCallback, isClosed, isReconnecting, notifyReconnected, requireOpenForCommand, resetReconnectAttempts, send, waitForAuthentication, waitForAuthenticationResult

Methods inherited from class java.lang.Object

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

Constructor Details

AlpacaTradingStream

public AlpacaTradingStream(okhttp3.OkHttpClient httpClient,
 AlpacaCredentials credentials,
 TradingEnvironment environment,
 TradingStreamListener listener)

Creates a new trading stream client. Use AlpacaClientFactory.tradingStream(markets.alpaca.client.AlpacaCredentials, markets.alpaca.client.ws.TradingEnvironment, markets.alpaca.client.ws.TradingStreamListener) rather than calling this constructor directly.

AlpacaTradingStream

public AlpacaTradingStream(okhttp3.OkHttpClient httpClient,
 AlpacaCredentials credentials,
 TradingEnvironment environment,
 TradingStreamListener listener,
 AlpacaStreamReconnectPolicy reconnectPolicy)

Creates a new trading stream client with a custom reconnect policy. Use AlpacaClientFactory.tradingStream(markets.alpaca.client.AlpacaCredentials, markets.alpaca.client.ws.TradingEnvironment, markets.alpaca.client.ws.TradingStreamListener) rather than calling this constructor directly.

AlpacaTradingStream

public AlpacaTradingStream(okhttp3.OkHttpClient httpClient,
 AlpacaCredentials credentials,
 TradingEnvironment environment,
 TradingStreamListener listener,
 AlpacaStreamReconnectPolicy reconnectPolicy,
 Executor callbackExecutor)

Creates a new trading stream client with a custom reconnect policy and listener executor. Use AlpacaClientFactory.tradingStream(markets.alpaca.client.AlpacaCredentials, markets.alpaca.client.ws.TradingEnvironment, markets.alpaca.client.ws.TradingStreamListener) rather than calling this constructor directly.

AlpacaTradingStream

public AlpacaTradingStream(okhttp3.OkHttpClient httpClient,
 AlpacaCredentials credentials,
 String url,
 TradingStreamListener listener)

Creates a new trading stream client for a custom WebSocket URL.

Method Details

buildRequest

protected okhttp3.Request buildRequest()

Description copied from class: AbstractAlpacaStream

Builds the WebSocket upgrade request (URL + any auth headers).

Specified by:

buildRequest in class AbstractAlpacaStream

handleOpen

protected void handleOpen(okhttp3.WebSocket ws)

Description copied from class: AbstractAlpacaStream

Called when the WebSocket connection is open.

Specified by:

handleOpen in class AbstractAlpacaStream

handleText

protected void handleText(okhttp3.WebSocket ws,
 String text)

Description copied from class: AbstractAlpacaStream

Called for each text frame received from the server.

Specified by:

handleText in class AbstractAlpacaStream

handleClose

protected void handleClose(int code,
 String reason,
 boolean willReconnect)

Description copied from class: AbstractAlpacaStream

Called when the connection closes, either cleanly or due to an error.

Specified by:

handleClose in class AbstractAlpacaStream

Parameters:

code - WebSocket close code, or -1 for transport failures

reason - human-readable close reason

notifyReconnecting

protected void notifyReconnecting(int attempt)

Description copied from class: AbstractAlpacaStream

Called just before a reconnect attempt is initiated.

Overrides:

notifyReconnecting in class AbstractAlpacaStream

Parameters:

attempt - 1-based attempt counter

listen

public void listen(TradingSubscription subscription)

Subscribes to (or replaces) the active set of trading streams.

The streams list is authoritative: to stop a stream, send the list without it. Can be called before authentication — the request is queued and sent after auth completes.

connect

public void connect(TradingSubscription subscription)

Opens the stream and starts listening after authentication completes.

This is equivalent to calling listen(TradingSubscription) before AbstractAlpacaStream.connect(); the requested streams are replayed when the server authorizes the connection.