enables reconnect including REST GET for abnormally closed websockets

Enables the use of the re-connector code for abnormally closed websocket
connections. The (re-)connector searches for Subscription resources,
downloads existing Task and QuestionnaireResponse resources before
establishing the Task and QuestionnaireResponse websocket connections.

Fixes #233

dsf-fhir/dsf-fhir-websocket-client/src/main/java/dev/dsf/fhir/client/ClientEndpoint.java

@@ -1,5 +1,6 @@
 package dev.dsf.fhir.client;
 
+import java.util.EnumSet;
 import java.util.function.Consumer;
 import java.util.function.Supplier;
 
@@ -80,7 +81,8 @@ public void onClose(Session session, CloseReason closeReason)
 		logger.warn("Websocket closed, session {}: {} - {}", session.getId(), closeReason.getCloseCode().getCode(),
 				closeReason.getReasonPhrase());
 
-		if (CloseReason.CloseCodes.CANNOT_ACCEPT.equals(closeReason.getCloseCode()))
+		if (EnumSet.of(CloseReason.CloseCodes.CANNOT_ACCEPT, CloseReason.CloseCodes.CLOSED_ABNORMALLY)
+				.contains(closeReason.getCloseCode()))
 		{
 			logger.info("Trying to reconnect websocket");
 			reconnector.run();

dsf-fhir/dsf-fhir-websocket-client/src/main/java/dev/dsf/fhir/client/WebsocketClientTyrus.java

@@ -90,8 +90,8 @@ public boolean onDisconnect(CloseReason closeReason)
 	private final String userAgentValue;
 	private final ClientEndpoint endpoint;
 
-	private ClientManager manager;
-	private Session connection;
+	private volatile ClientManager manager;
+	private volatile Session connection;
 	private volatile boolean closed;
 
 	public WebsocketClientTyrus(Runnable reconnector, URI wsUri, KeyStore trustStore, KeyStore keyStore,
@@ -131,6 +131,8 @@ public void connect()
 		if (manager != null)
 			throw new IllegalStateException("Allready connecting/connected");
 
+		closed = false;
+
 		manager = ClientManager.createClient();
 		manager.getProperties().put(ClientProperties.RECONNECT_HANDLER, reconnectHandler);
 		manager.getProperties().put(ClientProperties.SSL_ENGINE_CONFIGURATOR, new SslEngineConfigurator(sslContext));