SockJsClient抛出ClassCastException

Question

我正在尝试在我的intellij IDEA插件中配置WebSocket连接，我得到

func imageIsEmpty(_ image: UIImage) -> Bool {
    guard let cgImage = image.cgImage,
          let dataProvider = cgImage.dataProvider else
    {
        return true
    }

    let pixelData = dataProvider.data
    let data: UnsafePointer<UInt8> = CFDataGetBytePtr(pixelData)
    let imageWidth = Int(image.size.width)
    let imageHeight = Int(image.size.height)
    for x in 0..<imageWidth {
        for y in 0..<imageHeight {
            let pixelIndex = ((imageWidth * y) + x) * 4
            let r = data[pixelIndex]
            let g = data[pixelIndex + 1]
            let b = data[pixelIndex + 2]
            let a = data[pixelIndex + 3]
            if a != 0 {
                if r != 0 || g != 0 || b != 0 {
                    return false
                }
            }
        }
    }

    return true 
 }

当我在独立的应用程序中使用此代码时，一切正常。

 2019-10-25 19:17:56,835 [  81159]  ERROR - roject.impl.ProjectManagerImpl - From the listener com.homework.plugin.PluginTasksProjectComponent$1@1c0e28b2 (class com.homework.plugin.PluginTasksProjectComponent$1) 
java.lang.ClassCastException: com.fasterxml.jackson.module.kotlin.KotlinModule cannot be cast to com.fasterxml.jackson.databind.Module
    at org.springframework.http.converter.json.Jackson2ObjectMapperBuilder.registerWellKnownModulesIfAvailable(Jackson2ObjectMapperBuilder.java:811)
    at org.springframework.http.converter.json.Jackson2ObjectMapperBuilder.configure(Jackson2ObjectMapperBuilder.java:650)
    at org.springframework.http.converter.json.Jackson2ObjectMapperBuilder.build(Jackson2ObjectMapperBuilder.java:633)
    at org.springframework.http.converter.json.MappingJackson2HttpMessageConverter.<init>(MappingJackson2HttpMessageConverter.java:59)
    at org.springframework.http.converter.support.AllEncompassingFormHttpMessageConverter.<init>(AllEncompassingFormHttpMessageConverter.java:76)
    at org.springframework.web.client.RestTemplate.<init>(RestTemplate.java:150)
    at org.springframework.web.socket.sockjs.client.RestTemplateXhrTransport.<init>(RestTemplateXhrTransport.java:64)
    at com.homework.plugin.chat.WebSocket.<init>(WebSocket.java:39)
    at com.homework.plugin.PluginTasksProjectComponent$1.projectOpened(PluginTasksProjectComponent.java:72)

在public class WebSocket { private static final String TOPIC_ADDED = "/topic/discussion%s/comments/added"; private static final String TOPIC_UPDATED = "/topic/discussion%s/comments/updated"; private static final String TOPIC_DELETED = "/topic/discussion%s/comments/deleted"; private static final String TOPIC_SEND = "/topic/discussion%s/comments"; private final String URL = "https://my.url/stomp-messages"; private StompSession stompSession; private StompSessionHandler sessionHandler; private StompSession.Subscription currentSubscription; public WebSocket(JTextPane messagesTextPane) { sessionHandler = new MySessionHandler(messagesTextPane); List<Transport> transports = new ArrayList<>(2); transports.add(new WebSocketTransport(new StandardWebSocketClient())); transports.add(new RestTemplateXhrTransport()); WebSocketClient client = new SockJsClient(transports); WebSocketStompClient stompClient = new WebSocketStompClient(client); stompClient.setMessageConverter(new MappingJackson2MessageConverter()); stompClient.setTaskScheduler(new ConcurrentTaskScheduler()); try { stompSession = stompClient.connect(URL, sessionHandler).get(); } catch (InterruptedException | ExecutionException e) { e.printStackTrace(); } } 对象创建所在的行抛出异常。  Jackson2ObjectMapperBuilder尝试将一些Kotlin模块转换为Module类，但我不明白为什么该代码块无法在独立应用程序中执行。

也许有人知道，问题的根源？

Answer 1

问题解决了。我应该添加此依赖项

<dependency>
    <groupId>com.fasterxml.jackson.module</groupId>
    <artifactId>jackson-module-kotlin</artifactId>
    <version>2.10.0</version>
</dependency>