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json - Springboot Websockets：无法读取 JSON：无法从 START_ARRAY 令牌中反序列化“someclass”实例

问题描述

我正在尝试通过 SpringBoot 中的 websockets 发送 JSON 对象，但是在我的控制器上出现以下错误：

org.springframework.messaging.converter.MessageConversionException: Could not read JSON: Cannot deserialize instance of `com.websocket.demo.bean.MessageBean` out of START_ARRAY token
 at [Source: (byte[])"[object Object]"; line: 1, column: 1]; nested exception is com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot deserialize instance of `com.websocket.demo.bean.MessageBean` out of START_ARRAY token
 at [Source: (byte[])"[object Object]"; line: 1, column: 1]
    at org.springframework.messaging.converter.MappingJackson2MessageConverter.convertFromInternal(MappingJackson2MessageConverter.java:235) ~[spring-messaging-5.0.10.RELEASE.jar:5.0.10.RELEASE]
    at org.springframework.messaging.converter.AbstractMessageConverter.fromMessage(AbstractMessageConverter.java:181) ~[spring-messaging-5.0.10.RELEASE.jar:5.0.10.RELEASE]
    at org.springframework.messaging.converter.CompositeMessageConverter.fromMessage(CompositeMessageConverter.java:70) ~[spring-messaging-5.0.10.RELEASE.jar:5.0.10.RELEASE]
    at org.springframework.messaging.handler.annotation.support.PayloadArgumentResolver.resolveArgument(PayloadArgumentResolver.java:137) ~[spring-messaging-5.0.10.RELEASE.jar:5.0.10.RELEASE]
    at org.springframework.messaging.handler.invocation.HandlerMethodArgumentResolverComposite.resolveArgument(HandlerMethodArgumentResolverComposite.java:116) ~[spring-messaging-5.0.10.RELEASE.jar:5.0.10.RELEASE]
    at org.springframework.messaging.handler.invocation.InvocableHandlerMethod.getMethodArgumentValues(InvocableHandlerMethod.java:137) ~[spring-messaging-5.0.10.RELEASE.jar:5.0.10.RELEASE]
    at org.springframework.messaging.handler.invocation.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:109) ~[spring-messaging-5.0.10.RELEASE.jar:5.0.10.RELEASE]
    at org.springframework.messaging.handler.invocation.AbstractMethodMessageHandler.handleMatch(AbstractMethodMessageHandler.java:517) [spring-messaging-5.0.10.RELEASE.jar:5.0.10.RELEASE]
    at org.springframework.messaging.simp.annotation.support.SimpAnnotationMethodMessageHandler.handleMatch(SimpAnnotationMethodMessageHandler.java:495) [spring-messaging-5.0.10.RELEASE.jar:5.0.10.RELEASE]
    at org.springframework.messaging.simp.annotation.support.SimpAnnotationMethodMessageHandler.handleMatch(SimpAnnotationMethodMessageHandler.java:88) [spring-messaging-5.0.10.RELEASE.jar:5.0.10.RELEASE]
    at org.springframework.messaging.handler.invocation.AbstractMethodMessageHandler.handleMessageInternal(AbstractMethodMessageHandler.java:475) [spring-messaging-5.0.10.RELEASE.jar:5.0.10.RELEASE]
    at org.springframework.messaging.handler.invocation.AbstractMethodMessageHandler.handleMessage(AbstractMethodMessageHandler.java:411) [spring-messaging-5.0.10.RELEASE.jar:5.0.10.RELEASE]
    at org.springframework.messaging.support.ExecutorSubscribableChannel$SendTask.run(ExecutorSubscribableChannel.java:138) [spring-messaging-5.0.10.RELEASE.jar:5.0.10.RELEASE]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_181]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_181]
    at java.lang.Thread.run(Thread.java:748) [na:1.8.0_181]

这就是我的控制器的样子：

 //This is intended to particular user;
   @MessageMapping("/message")
   public void processMessage( MessageBean message/* @DestinationVariable int id, @DestinationVariable int targetUserId*/ )
   {
      String channel = userService.generateConnectionString( message.getRecieverId() );
      boolean isError = false;
      if ( channel == null )
      {
         isError = true;
      }
      Map< String, Object > response = generateResponse( isError, channel, "Connection Request Sent Successfuly" );
      messagingTemplate.convertAndSend( "/queue/greeting/" + message.getRecieverId(), response);
   }

我尝试发送的请求对象：

$scope.sendMessage1 = function()
    {   
        $scope.subscribe(1);
        $scope.message = {};
        $scope.message.senderId = 2;
        $scope.message.recieverId = 1;
        $scope.message.text = "Hello from user 2";
        var sendObject = JSON.stringify($scope.message);
        //sendObject = "{"senderId":1,"recieverId":2,"text":"Hello from user 1"}"
        console.log(sendObject);
        client.send("/app/message",{},sendObject);
    };

有人能告诉我如何解决这个异常吗？

标签： jsonspring-bootjacksonspring-websocket

解决方案

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