Websocket的单元测试返回Null

Question

我正在尝试用JUnit在Springboot中实现Websocket的单元测试。

我正在关注这个链接，它运行良好，但结果为null，当我用浏览器测试我的websocket时，它会发送期望的结果。

让我展示一下我的测试课

@ExtendWith(SpringExtension.class)
@SpringBootTest(classes =Main.class)
@WebAppConfiguration
public class WebSocketTest {
static final String WEBSOCKET_URI = "http://localhost:8080/api/realtimedata";
static final String WEBSOCKET_TOPIC = "/realtimedata";
BlockingQueue<WebSocketData> blockingQueue;
WebSocketStompClient stompClient;
@BeforeEach
public void setup() {
blockingQueue = new LinkedBlockingDeque<>();
stompClient = new WebSocketStompClient(new SockJsClient(
asList(new WebSocketTransport(new StandardWebSocketClient()))));
}
@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 = "{"groupId":"grp-1", "accountId":"acc-1", "userId":"usr-1"}";
session.send(WEBSOCKET_TOPIC, message.getBytes()); 
Assertions.assertEquals("trying to figureout", blockingQueue.poll(1, SECONDS));
}
class DefaultStompFrameHandler implements StompFrameHandler {
@Override
public Type getPayloadType(StompHeaders stompHeaders) {
return WebSocketData.class;
}
@Override
public void handleFrame(StompHeaders stompHeaders, Object o) {
blockingQueue.offer((WebSocketData) o);
}
}

}

这是我的WebSocketConfiguration级

@Configuration
@EnableWebSocketMessageBroker
public class WebSocketConfiguration implements WebSocketMessageBrokerConfigurer {
@Override
public void configureMessageBroker(MessageBrokerRegistry registry) {
registry.enableSimpleBroker("/realtimedata");
registry.setApplicationDestinationPrefixes("/wsconn");
}
@Override
public void registerStompEndpoints(StompEndpointRegistry registry) {
registry.addEndpoint("/realtimedata")
.setAllowedOrigins("*")
.withSockJS();
}

}

这是我从服务器得到的响应

org.opentest4j.AssertionFailedError: 
Expected :trying to figureout
Actual   :null

更新：

在下面的答案中添加了Rieckpil建议的更改后，经过进一步的研究，我的测试课现在看起来是这样的

@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
public class ServerWebSocketTest {
@LocalServerPort
private Integer port;
static final String WEBSOCKET_TOPIC = "/realtimedata";
BlockingQueue<WebSocketData> blockingQueue;
WebSocketStompClient stompClient;
@BeforeEach
public void setup() {
blockingQueue = new LinkedBlockingDeque<>();
stompClient = new WebSocketStompClient(new SockJsClient(
asList(new WebSocketTransport(new StandardWebSocketClient()))));
// might be required
stompClient.setMessageConverter(new MappingJackson2MessageConverter());
}
@Test
public void shouldReceiveAMessageFromTheServer() throws Exception {
StompSession session = stompClient
.connect(getWsPath(), **new DefaultStompFrameHandler()** {
})
.get(1, TimeUnit.SECONDS);
session.subscribe(WEBSOCKET_TOPIC, new DefaultStompFrameHandler());
String message = "{"groupId":"grp-1", "accountId":"acc-1", "userId":"usr-1"}";
session.send(WEBSOCKET_TOPIC, message.getBytes());
Assertions.assertEquals("trying to figureout", blockingQueue.poll(1, TimeUnit.SECONDS));
}
class DefaultStompFrameHandler **extends StompSessionHandlerAdapter**{   
@Override
public Type getPayloadType(StompHeaders stompHeaders) {
return WebSocketData.class;
}
@Override
public void handleFrame(StompHeaders stompHeaders, Object o) {
blockingQueue.offer((WebSocketData) o);
}
**@Override
public void handleException(StompSession session, StompCommand command, StompHeaders headers, byte[] payload, Throwable exception) {
exception.printStackTrace();
}**
}
private String getWsPath() {
return String.format("ws://localhost:%d/location_services/realtimedata", port);
}

}

在这些更改之后，我现在可以在日志中打印堆栈

这是我在这些改变后得到的例外

org.springframework.messaging.converter.MessageConversionException: Could not read JSON: Cannot construct instance of `com.convo.locationservices.websocket.WebSocketData` (although at least one Creator exists): no String-argument constructor/factory method to deserialize from String value ('eyJncm91cElkIjoiZ3JwLTEiLCAiYWNjb3VudElkIjoiYWNjLTEiLCAidXNlcklkIjoidXNyLTEifQ==')
at [Source: (byte[])""eyJncm91cElkIjoiZ3JwLTEiLCAiYWNjb3VudElkIjoiYWNjLTEiLCAidXNlcklkIjoidXNyLTEifQ==""; line: 1, column: 1]; nested exception is com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot construct instance of `com.convo.locationservices.websocket.WebSocketData` (although at least one Creator exists): no String-argument constructor/factory method to deserialize from String value ('eyJncm91cElkIjoiZ3JwLTEiLCAiYWNjb3VudElkIjoiYWNjLTEiLCAidXNlcklkIjoidXNyLTEifQ==')
at [Source: (byte[])""eyJncm91cElkIjoiZ3JwLTEiLCAiYWNjb3VudElkIjoiYWNjLTEiLCAidXNlcklkIjoidXNyLTEifQ==""; line: 1, column: 1], failedMessage=GenericMessage [payload=byte[82], headers={simpMessageType=MESSAGE, stompCommand=MESSAGE, nativeHeaders={destination=[/realtimedata], content-type=[application/json], subscription=[0], message-id=[cc55448f0b4f447d8f6bc7662acd15db-0], content-length=[82]}, simpSubscriptionId=0, contentType=application/json, simpSessionId=2df73ca0-e13b-c479-4591-37e9f7e8d689, simpDestination=/realtimedata}]
at org.springframework.messaging.converter.MappingJackson2MessageConverter.convertFromInternal(MappingJackson2MessageConverter.java:235)
at org.springframework.messaging.converter.AbstractMessageConverter.fromMessage(AbstractMessageConverter.java:197)
at org.springframework.messaging.converter.AbstractMessageConverter.fromMessage(AbstractMessageConverter.java:188)
at org.springframework.messaging.simp.stomp.DefaultStompSession.invokeHandler(DefaultStompSession.java:477)
at org.springframework.messaging.simp.stomp.DefaultStompSession.handleMessage(DefaultStompSession.java:429)
at org.springframework.web.socket.messaging.WebSocketStompClient$WebSocketTcpConnectionHandlerAdapter.handleMessage(WebSocketStompClient.java:340)
at org.springframework.web.socket.handler.WebSocketHandlerDecorator.handleMessage(WebSocketHandlerDecorator.java:75)
at org.springframework.web.socket.handler.LoggingWebSocketHandlerDecorator.handleMessage(LoggingWebSocketHandlerDecorator.java:56)
at org.springframework.web.socket.sockjs.client.AbstractClientSockJsSession.handleMessageFrame(AbstractClientSockJsSession.java:294)
at org.springframework.web.socket.sockjs.client.AbstractClientSockJsSession.handleFrame(AbstractClientSockJsSession.java:230)
at org.springframework.web.socket.sockjs.client.WebSocketTransport$ClientSockJsWebSocketHandler.handleTextMessage(WebSocketTransport.java:163)
at org.springframework.web.socket.handler.AbstractWebSocketHandler.handleMessage(AbstractWebSocketHandler.java:43)
at org.springframework.web.socket.adapter.standard.StandardWebSocketHandlerAdapter.handleTextMessage(StandardWebSocketHandlerAdapter.java:114)
at org.springframework.web.socket.adapter.standard.StandardWebSocketHandlerAdapter.access$000(StandardWebSocketHandlerAdapter.java:43)
at org.springframework.web.socket.adapter.standard.StandardWebSocketHandlerAdapter$3.onMessage(StandardWebSocketHandlerAdapter.java:85)
at org.springframework.web.socket.adapter.standard.StandardWebSocketHandlerAdapter$3.onMessage(StandardWebSocketHandlerAdapter.java:82)
at org.apache.tomcat.websocket.WsFrameBase.sendMessageText(WsFrameBase.java:395)
at org.apache.tomcat.websocket.WsFrameBase.processDataText(WsFrameBase.java:495)
at org.apache.tomcat.websocket.WsFrameBase.processData(WsFrameBase.java:294)
at org.apache.tomcat.websocket.WsFrameBase.processInputBuffer(WsFrameBase.java:133)
at org.apache.tomcat.websocket.WsFrameClient.processSocketRead(WsFrameClient.java:95)
at org.apache.tomcat.websocket.WsFrameClient.resumeProcessing(WsFrameClient.java:209)
at org.apache.tomcat.websocket.WsFrameClient.access$300(WsFrameClient.java:31)
at org.apache.tomcat.websocket.WsFrameClient$WsFrameClientCompletionHandler.doResumeProcessing(WsFrameClient.java:186)
at org.apache.tomcat.websocket.WsFrameClient$WsFrameClientCompletionHandler.completed(WsFrameClient.java:163)
at org.apache.tomcat.websocket.WsFrameClient$WsFrameClientCompletionHandler.completed(WsFrameClient.java:148)
at java.base/sun.nio.ch.Invoker.invokeUnchecked(Invoker.java:127)
at java.base/sun.nio.ch.Invoker$2.run(Invoker.java:219)
at java.base/sun.nio.ch.AsynchronousChannelGroupImpl$1.run(AsynchronousChannelGroupImpl.java:112)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot construct instance of `com.convo.locationservices.websocket.WebSocketData` (although at least one Creator exists): no String-argument constructor/factory method to deserialize from String value ('eyJncm91cElkIjoiZ3JwLTEiLCAiYWNjb3VudElkIjoiYWNjLTEiLCAidXNlcklkIjoidXNyLTEifQ==')
at [Source: (byte[])""eyJncm91cElkIjoiZ3JwLTEiLCAiYWNjb3VudElkIjoiYWNjLTEiLCAidXNlcklkIjoidXNyLTEifQ==""; line: 1, column: 1]
at com.fasterxml.jackson.databind.exc.MismatchedInputException.from(MismatchedInputException.java:63)
at com.fasterxml.jackson.databind.DeserializationContext.reportInputMismatch(DeserializationContext.java:1432)
at com.fasterxml.jackson.databind.DeserializationContext.handleMissingInstantiator(DeserializationContext.java:1062)
at com.fasterxml.jackson.databind.deser.ValueInstantiator._createFromStringFallbacks(ValueInstantiator.java:371)
at com.fasterxml.jackson.databind.deser.std.StdValueInstantiator.createFromString(StdValueInstantiator.java:323)
at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.deserializeFromString(BeanDeserializerBase.java:1373)
at com.fasterxml.jackson.databind.deser.BeanDeserializer._deserializeOther(BeanDeserializer.java:171)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:161)
at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:4218)
at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3309)
at org.springframework.messaging.converter.MappingJackson2MessageConverter.convertFromInternal(MappingJackson2MessageConverter.java:219)
... 31 more
            
org.opentest4j.AssertionFailedError: 
Expected :trying to figureout
Actual   :null

有人能告诉我我做错了什么吗？

谢谢。

Answer 1

您应该将集成测试配置为使用启动的Spring上下文，而不是硬编码8080。

此外，请确保为您的WebSocketStompClient配置了适合您的用例的MessageConverter。默认值为SimpleMessageConverter。当您发送byte[]时，ByteArrayMessageConverter应该适合。

您的测试可以重构为以下内容：

@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
public class Test {
@LocalServerPort
private Integer port;

static final String WEBSOCKET_TOPIC = "/realtimedata";
BlockingQueue<WebSocketData> blockingQueue;
WebSocketStompClient stompClient;
@BeforeEach
public void setup() {
blockingQueue = new LinkedBlockingDeque<>();
stompClient = new WebSocketStompClient(new SockJsClient(
asList(new WebSocketTransport(new StandardWebSocketClient()))));
webSocketStompClient.setMessageConverter(new ByteArrayMessageConverter()); 
}
@Test
public void shouldReceiveAMessageFromTheServer() throws Exception {
StompSession session = stompClient
.connect(getWsPath(), new StompSessionHandlerAdapter() {
})
.get(1, SECONDS);
session.subscribe(WEBSOCKET_TOPIC, new DefaultStompFrameHandler());
String message = "{"groupId":"grp-1", "accountId":"acc-1", "userId":"usr-1"}";
session.send(WEBSOCKET_TOPIC, message.getBytes());
Assertions.assertEquals("trying to figureout", blockingQueue.poll(1, SECONDS));
}
class DefaultStompFrameHandler implements StompFrameHandler {
@Override
public Type getPayloadType(StompHeaders stompHeaders) {
return WebSocketData.class;
}
@Override
public void handleFrame(StompHeaders stompHeaders, Object o) {
blockingQueue.offer((WebSocketData) o);
}
}

private String getWsPath() {
return String.format("ws://localhost:%d/api/realtimedata", port);
}
}

该测试将启动整个Spring上下文，即随机端口上的嵌入式servlet容器，并尝试连接到您的端点。

Answer 2

我也遇到过同样的问题。在我的情况下，我忘记添加默认构造函数和所有参数构造函数

请检查您的WebSocketData类以添加构造函数