Spring Boot Websocket Throws "Connection Refused" in SockJS Client Test - spring-boot

Question

I am working on a Spring Boot Server Project which offered simple REST resources until now. In order to push notifications to the client I want to add a websocket connection. To test this connection I have written a Integration Test using a SockJS Client based on this tutorial :
http://rafaelhz.github.io/testing-websockets/
Problem is that the Connection is refused with the following error:
org.springframework.web.client.ResourceAccessException: I/O error on GET request for "http://localhost:9090/websocket/info": Connection refused (Connection refused); nested exception is java.net.ConnectException: Connection refused (Connection refused)
My Websocket Configuration is as follows:
import org.springframework.context.annotation.Configuration;
import org.springframework.messaging.simp.config.MessageBrokerRegistry;
import org.springframework.web.socket.config.annotation.AbstractWebSocketMessageBrokerConfigurer;
import org.springframework.web.socket.config.annotation.EnableWebSocketMessageBroker;
import org.springframework.web.socket.config.annotation.StompEndpointRegistry;
#Configuration
#EnableWebSocketMessageBroker
public class WebSocketConfig extends AbstractWebSocketMessageBrokerConfigurer {
#Override
public void configureMessageBroker(MessageBrokerRegistry config) {
config.enableSimpleBroker("/topic");
config.setApplicationDestinationPrefixes("/app");
}
#Override
public void registerStompEndpoints(StompEndpointRegistry registry) {
registry
.addEndpoint("/websocket")
.setAllowedOrigins("*")
.withSockJS();
}
}
I can see in the that the socket endpoint is mapped int the log:
2017-07-14 15:22:59.561 INFO 13765 --- [ main] o.s.w.s.s.s.WebSocketHandlerMapping : Mapped URL path [/websocket/**] onto handler of type [class org.springframework.web.socket.sockjs.support.SockJsHttpRequestHandler]
The Server Port is set to 9090 in the application.yml file:
server:
port: 9090
The following unit test is not able to connect to the socket:
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.annotation.DirtiesContext;
import org.springframework.test.context.ActiveProfiles;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.web.socket.client.standard.StandardWebSocketClient;
import org.springframework.web.socket.messaging.WebSocketStompClient;
import org.springframework.web.socket.sockjs.client.SockJsClient;
import org.springframework.web.socket.sockjs.client.WebSocketTransport;
import org.springframework.messaging.simp.stomp.StompFrameHandler;
import org.springframework.messaging.simp.stomp.StompHeaders;
import org.springframework.messaging.simp.stomp.StompSession;
import org.springframework.messaging.simp.stomp.StompSessionHandlerAdapter;
import java.lang.reflect.Type;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.LinkedBlockingDeque;
import static java.util.Arrays.asList;
import static java.util.concurrent.TimeUnit.SECONDS;
#RunWith(SpringRunner.class)
#SpringBootTest
#ActiveProfiles("test")
//#DirtiesContext(classMode = DirtiesContext.ClassMode.AFTER_EACH_TEST_METHOD)
public class WebSocketConnectionTest {
static final String WEBSOCKET_URI = "ws://localhost:9090/websocket";
static final String WEBSOCKET_TOPIC = "/topic";
BlockingQueue<String> blockingQueue;
WebSocketStompClient stompClient;
#Before
public void setup() {
blockingQueue = new LinkedBlockingDeque<>();
stompClient = new WebSocketStompClient(new SockJsClient(
asList(new WebSocketTransport(new StandardWebSocketClient()))));
System.out.println(WEBSOCKET_URI);
}
#Test
public void shouldReceiveAMessageFromTheServer() throws Exception {
StompSession session = stompClient
.connect(WEBSOCKET_URI, new StompSessionHandlerAdapter() {})
.get(1, SECONDS);
session.subscribe(WEBSOCKET_TOPIC, new DefaultStompFrameHandler());
String message = "MESSAGE TEST";
session.send(WEBSOCKET_TOPIC, message.getBytes());
Assert.assertEquals(message, blockingQueue.poll(1, SECONDS));
}
class DefaultStompFrameHandler implements StompFrameHandler {
#Override
public Type getPayloadType(StompHeaders stompHeaders) {
return byte[].class;
}
#Override
public void handleFrame(StompHeaders stompHeaders, Object o) {
blockingQueue.offer(new String((byte[]) o));
}
}
}
The connection is refused. Im fairly certain that this happens because the URI endpoint does not exist, but I don't know why. Does somebody know if there is a error in the URI or if something else leads to the refused connection ?

Answer 1

I found out the cause of the problem. The endpoint did not exist on PORT 9090. That is because the #SpringBootTest Annotation sets the WebEnvironment to WebEnvironment.MOCK by default. In this configuration No Embedded Servlet is started and therefor and no port exists, only MockMvc-based testing is possible. In order to start an Embedded servlet
the Environment has to be set to WebEnvironment.RANDOM_PORT or WebEnvironment.DEFINED_PORT. I set it to DEFINED_PORT so that the port 9090 from my application.yml is used. By Setting the Environment the test runs correctly.
#RunWith(SpringRunner.class)
#SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.DEFINED_PORT)//!!!!!
#ActiveProfiles("test")
#DirtiesContext(classMode = DirtiesContext.ClassMode.AFTER_EACH_TEST_METHOD)
public class WebSocketConnectionTest {
String WEBSOCKET_URI = "ws://localhost:9090/websocket";
String WEBSOCKET_TOPIC = "/topic";
.
.
.