我如何使用注射给Postman拨打Stomp消息？ 我有以下... @messagemapping（“/hello”） @Sendto（“/topic/问候”） @throws（异常:: class） 有趣的问候（消息：testmessage）：问候{ 但是，当我跑步和S ...

Question

，但是，当我跑步并发送消息时，我得到了

Caused by: com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot construct instance of `org.gleason.love_monkey.model.TestMessage` (although at least one Creator exists): cannot deserialize from Object value (no delegate- or property-based Creator)
 at [Source: REDACTED (`StreamReadFeature.INCLUDE_SOURCE_IN_LOCATION` disabled); line: 1, column: 2]
    at com.fasterxml.jackson.databind.exc.MismatchedInputException.from(MismatchedInputException.java:63) ~[jackson-databind-2.18.2.jar:2.18.2]
    at com.fasterxml.jackson.databind.DeserializationContext.reportInputMismatch(DeserializationContext.java:1754) ~[jackson-databind-2.18.2.jar:2.18.2]

我试图更改为

    fun greeting(message: Any): Greeting {
        val jsonString: String
        // Log the incoming message
        if (message is ByteArray) {
            jsonString = byteArrayToString(message)
        } else {
            jsonString = objectMapper.writeValueAsString(message)
        }
        logger.info("Received message: $jsonString")

当我这样做时，我看到它是字节编码但正确的...

2025-01-31T18:40:40.006-05:00 INFO 49504 --- [love-monkey] [nboundChannel-1] o.g.l.controller.WebsocketController : Received message: {"name":"me"}

使用该过程制作框架

在此处描述

数据类是

data class TestMessage(val name: String)

我错过了什么我如何键入消息并仍然使用Postman update

我试图更改为

        val jsonString: String
        // Log the incoming message
        if (message is ByteArray) {
            jsonString = byteArrayToString(message)
        } else {
            jsonString = objectMapper.writeValueAsString(message)
        }
        logger.info("Received message: $jsonString")

        // Log the JSON string before deserialization
        logger.info("JSON string to be deserialized: ${jsonString.trim()}")

        val testMessage: TestMessage = objectMapper.readValue(jsonString.trim(), TestMessage::class.java)

当我调试到对象映射器时，它看起来正确...

但仍然抛出

com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot construct instance of `org.gleason.love_monkey.model.TestMessage` (although at least one Creator exists): cannot deserialize from Object value (no delegate- or property-based Creator)
 at [Source: REDACTED (`StreamReadFeature.INCLUDE_SOURCE_IN_LOCATION` disabled); line: 1, column: 2]
    at com.fasterxml.jackson.databind.exc.MismatchedInputException.from(MismatchedInputException.java:63) ~[jackson-databind-2.18.2.jar:2.18.2]
    at com.fasterxml.jackson.databind.DeserializationContext.reportInputMismatch(DeserializationContext.java:1754) ~[jackson-databind-2.18.2.jar:2.18.2]
    at com.fasterxml.jackson.databind.DeserializationContext.handleMissingInstantiator(DeserializationContext.java:1379) ~[jackson-databind-2.18.2.jar:2.18.2]
    at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.deserializeFromObjectUsingNonDefault(BeanDeserializerBase.java:1512) ~[jackson-databind-2.18.2.jar:2.18.2]
    at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserializeFromObject(BeanDeserializer.java:348) ~[jackson-databind-2.18.2.jar:2.18.2]
    at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:185) ~[jackson-databind-2.18.2.jar:2.18.2]
    at com.fasterxml.jackson.databind.deser.DefaultDeserializationContext.readRootValue(DefaultDeserializationContext.java:342) ~[jackson-databind-2.18.2.jar:2.18.2]
    at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:4917) ~[jackson-databind-2.18.2.jar:2.18.2]
    at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3860) ~[jackson-databind-2.18.2.jar:2.18.2]
    at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3828) ~[jackson-databind-2.18.2.jar:2.18.2]
    at org.gleason.love_monkey.controller.WebsocketController.greeting(WebsocketController.kt:35) ~[main/:na]
    at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
    at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
    at org.springframework.messaging.handler.invocation.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:169) ~[spring-messaging-6.2.2.jar:6.2.2]
    at org.springframework.messaging.handler.invocation.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:119) ~[spring-messaging-6.2.2.jar:6.2.2]
    at org.springframework.messaging.handler.invocation.AbstractMethodMessageHandler.handleMatch(AbstractMethodMessageHandler.java:568) ~[spring-messaging-6.2.2.jar:6.2.2]
    at org.springframework.messaging.simp.annotation.support.SimpAnnotationMethodMessageHandler.handleMatch(SimpAnnotationMethodMessageHandler.java:530) ~[spring-messaging-6.2.2.jar:6.2.2]
    at org.springframework.messaging.simp.annotation.support.SimpAnnotationMethodMessageHandler.handleMatch(SimpAnnotationMethodMessageHandler.java:93) ~[spring-messaging-6.2.2.jar:6.2.2]
    at org.springframework.messaging.handler.invocation.AbstractMethodMessageHandler.handleMessageInternal(AbstractMethodMessageHandler.java:522) ~[spring-messaging-6.2.2.jar:6.2.2]
    at org.springframework.messaging.handler.invocation.AbstractMethodMessageHandler.handleMessage(AbstractMethodMessageHandler.java:457) ~[spring-messaging-6.2.2.jar:6.2.2]
    at org.springframework.messaging.support.ExecutorSubscribableChannel$SendTask.run(ExecutorSubscribableChannel.java:152) ~[spring-messaging-6.2.2.jar:6.2.2]
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144) ~[na:na]
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642) ~[na:na]
    at java.base/java.lang.Thread.run(Thread.java:1583) ~[na:na]

ADD依赖关系 implementation("com.fasterxml.jackson.module:jackson-module-kotlin:2.18.2")

并用您的

ObjectMapper

实例注册Kotlin模块：val objectMapper = ObjectMapper().registerKotlinModule()

Answer 1

val string = "{\"name\":\"value\"}"
val byteArray = string.toByteArray()
val objectMapper = ObjectMapper().registerKotlinModule()
val messageFromString = objectMapper.readValue<TestMessage>(string)
val messageFromByteArray = objectMapper.readValue<TestMessage>(byteArray)