JarCastingStream client
Resilient client for Server sent events (SSE) and WebSockets based on Undertow
Maven
<dependency>
<groupId>io.joshworks.stream</groupId>
<artifactId>stream-client</artifactId>
<version>0.3</version>
</dependency>
Server sent events
Using fluent interface to connect to a SSE endpoint
public class App {
public static void main(final String[] args) {
SSEConnection connection = StreamClient.sse("http://my-service/sse")
.onEvent((data) -> System.out.println("New event: " + data))
.connect();
//onClose
//onOpen
//OnError
//then...
String lastEventId = connection.close();
}
}
Using dedicated handler to connect to a SSE endpoint
public class StreamHandler extends SseClientCallback {
@Override
public void onEvent(EventData event) {
System.out.println("New event: " + event);
}
@Override
public void onOpen() {
System.out.println("Connected");
}
@Override
public void onClose(String lastEventId) {
System.out.println("Closed, last event id: " + lastEventId);
}
@Override
public void onError(Exception e) {
System.err.println(e.getMessage());
}
}
public class App {
public static void main(final String[] args) {
SSEConnection connection = StreamClient.connect("http://my-service/sse", new StreamHandler());
//then...
String lastEventId = connection.close();
}
}
Websockets
Using fluent interface to connect to a WebSocket endpoint
public class App {
public static void main(final String[] args) {
WsConnection ws = StreamClient.ws("http://my-service/ws")
.onText((channel, message) -> System.out.println("Message received: " + message))
.connect();
//...
ws.close(new CloseMessage(CloseMessage.NORMAL_CLOSURE, "Bye"));
}
}
Using dedicated handler to connect to a WebSocket endpoint
public class MyEndpoint extends WebSocketClientEndpoint {
//..method signatures for brevity
protected void onConnect(WebSocketChannel channel, WebSocketHttpExchange exchange);
protected void onClose(WebSocketChannel channel, CloseMessage message) ;
protected void onPing(WebSocketChannel channel, BufferedBinaryMessage message);
protected void onPong(WebSocketChannel channel, BufferedBinaryMessage message);
protected void onText(WebSocketChannel channel, BufferedTextMessage message);
protected void onBinary(WebSocketChannel channel, BufferedBinaryMessage message);
protected void onError(WebSocketChannel channel, Exception error);
}
public class App {
public static void main(final String[] args) {
StreamClient.connect("http://my-service/ws", new MyEndpoint());
}
}
Sending message to a server
public class App {
public static void main(final String[] args) {
WsConnection ws = StreamClient.connect(...);
//undertow API
WebSockets.sendText("Hello", ws.channel(), null);
WebSockets.sendBinary(new byte[]{1}, ws.channel(), null);
//...etc
}
}
Connection retry
Disabled by default, to enable use maxRetries(int retries), optionally use .retryInterval(long intervalMillis) (default is 2000)
public class App {
public static void main(final String[] args) {
StreamClient.ws("http://my-service/ws")
.maxRetries(100)
.retryInterval(5000)
.connect();
}
}
XnioWorker configuration
The XnioWorker is shared across all clients (SSE and WS), in case of many connections, the thread pool can be tuned
public class App {
public static void main(final String[] args) {
OptionMap options = OptionMap.builder()
.set(Options.WORKER_IO_THREADS, 10)
.set(Options.TCP_NODELAY, true)
.set(Options.WORKER_NAME, "client-threads")
.set(Options.KEEP_ALIVE, true)
.getMap();
StreamClient.configure(options);
StreamClient.sse(...);
StreamClient.ws(...);
//...
}
}
Closing all connections
public class App {
public static void main(final String[] args) {
//...
StreamClient.shutdown();
}
}