java - Spring boot Test fails saying, Unable to start ServletWebServerApplicationContext due to missing ServletWebServerFactory bean

Question

Test Class:-

@RunWith(SpringRunner.class)
@SpringBootTest(classes = { WebsocketSourceConfiguration.class,
        WebSocketSourceIntegrationTests.class }, webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT, properties = {
                "websocket.path=/some_websocket_path", "websocket.allowedOrigins=*",
                "spring.cloud.stream.default-binder=kafka" })
public class WebSocketSourceIntegrationTests {

    private String port = "8080";

    @Test
    public void testWebSocketStreamSource() throws IOException, InterruptedException {
        StandardWebSocketClient webSocketClient = new StandardWebSocketClient();
        ClientWebSocketContainer clientWebSocketContainer = new ClientWebSocketContainer(webSocketClient,
                "ws://localhost:" + port + "/some_websocket_path");
        clientWebSocketContainer.start();
        WebSocketSession session = clientWebSocketContainer.getSession(null);
        session.sendMessage(new TextMessage("foo"));
        System.out.println("Done****************************************************");
    }

}

I have seen same issue here but nothing helped me. May I know what I'm missing ?

I have spring-boot-starter-tomcat as compile time dependency in the dependency Hierarchy.

Answer 1

This message says: You need to configure at least 1 ServletWebServerFactory bean in the ApplicationContext, so if you already have spring-boot-starter-tomcat you need to either autoconfigure that bean or to do it manually.

So, in the test there are only 2 configuration classes to load the applicationContext, these are = { WebsocketSourceConfiguration.class, WebSocketSourceIntegrationTests.class }, then at least in one of these classes there should be a @Bean method returning an instance of the desired ServletWebServerFactory.

* SOLUTION *

Make sure to load all the beans within your configuration class

WebsocketSourceConfiguration {
  @Bean 
  ServletWebServerFactory servletWebServerFactory(){
  return new TomcatServletWebServerFactory();
  }
}

OR also enable the AutoConfiguration to do a classpath scanning and auto-configuration of those beans.

@EnableAutoConfiguration
WebsocketSourceConfiguration

Can be done also at the Integration Test class.

@EnableAutoConfiguration
WebSocketSourceIntegrationTests

For more information check the SpringBootTest annotation documentation https://docs.spring.io/spring-boot/docs/current/api/org/springframework/boot/test/context/SpringBootTest.html