StompSubProtocolHandler allows version 1.0

Issue: SPR-17258

Author: rstoyanchev

spring-websocket/src/main/java/org/springframework/web/socket/messaging/StompSubProtocolHandler.java

@@ -85,6 +85,8 @@ public class StompSubProtocolHandler implements SubProtocolHandler, ApplicationE
 	 */
 	public static final String CONNECTED_USER_HEADER = "user-name";
 
+	private static final String[] SUPPORTED_VERSIONS = {"1.2", "1.1", "1.0"};
+
 	private static final Log logger = LogFactory.getLog(StompSubProtocolHandler.class);
 
 	private static final byte[] EMPTY_PAYLOAD = new byte[0];
@@ -524,15 +526,12 @@ private StompHeaderAccessor convertConnectAcktoStompConnected(StompHeaderAccesso
 
 		if (connectHeaders != null) {
 			Set<String> acceptVersions = connectHeaders.getAcceptVersion();
-			if (acceptVersions.contains("1.2")) {
-				connectedHeaders.setVersion("1.2");
-			}
-			else if (acceptVersions.contains("1.1")) {
-				connectedHeaders.setVersion("1.1");
-			}
-			else if (!acceptVersions.isEmpty()) {
-				throw new IllegalArgumentException("Unsupported STOMP version '" + acceptVersions + "'");
-			}
+			connectedHeaders.setVersion(
+					Arrays.stream(SUPPORTED_VERSIONS)
+							.filter(acceptVersions::contains)
+							.findAny()
+							.orElseThrow(() -> new IllegalArgumentException(
+									"Unsupported STOMP version '" + acceptVersions + "'")));
 		}
 
 		long[] heartbeat = (long[]) connectAckHeaders.getHeader(SimpMessageHeaderAccessor.HEART_BEAT_HEADER);

spring-websocket/src/test/java/org/springframework/web/socket/messaging/StompSubProtocolHandlerTests.java

@@ -126,7 +126,7 @@ public void handleMessageToClientWithSimpConnectAck() {
 
 		StompHeaderAccessor accessor = StompHeaderAccessor.create(StompCommand.CONNECT);
 		accessor.setHeartbeat(10000, 10000);
-		accessor.setAcceptVersion("1.0,1.1");
+		accessor.setAcceptVersion("1.0,1.1,1.2");
 		Message<?> connectMessage = MessageBuilder.createMessage(EMPTY_PAYLOAD, accessor.getMessageHeaders());
 
 		SimpMessageHeaderAccessor ackAccessor = SimpMessageHeaderAccessor.create(SimpMessageType.CONNECT_ACK);
@@ -137,7 +137,7 @@ public void handleMessageToClientWithSimpConnectAck() {
 
 		assertEquals(1, this.session.getSentMessages().size());
 		TextMessage actual = (TextMessage) this.session.getSentMessages().get(0);
-		assertEquals("CONNECTED\n" + "version:1.1\n" + "heart-beat:15000,15000\n" +
+		assertEquals("CONNECTED\n" + "version:1.2\n" + "heart-beat:15000,15000\n" +
 				"user-name:joe\n" + "\n" + "\u0000", actual.getPayload());
 	}
 
@@ -146,7 +146,7 @@ public void handleMessageToClientWithSimpConnectAckDefaultHeartBeat() {
 
 		StompHeaderAccessor accessor = StompHeaderAccessor.create(StompCommand.CONNECT);
 		accessor.setHeartbeat(10000, 10000);
-		accessor.setAcceptVersion("1.0,1.1");
+		accessor.setAcceptVersion("1.0");
 		Message<?> connectMessage = MessageBuilder.createMessage(EMPTY_PAYLOAD, accessor.getMessageHeaders());
 
 		SimpMessageHeaderAccessor ackAccessor = SimpMessageHeaderAccessor.create(SimpMessageType.CONNECT_ACK);
@@ -156,7 +156,7 @@ public void handleMessageToClientWithSimpConnectAckDefaultHeartBeat() {
 
 		assertEquals(1, this.session.getSentMessages().size());
 		TextMessage actual = (TextMessage) this.session.getSentMessages().get(0);
-		assertEquals("CONNECTED\n" + "version:1.1\n" + "heart-beat:0,0\n" +
+		assertEquals("CONNECTED\n" + "version:1.0\n" + "heart-beat:0,0\n" +
 				"user-name:joe\n" + "\n" + "\u0000", actual.getPayload());
 	}