Apache Camel java.lang.ClassCastException当从Spring XML配置组件动态构建路由时

Question

我们基于存储在数据库中的配置参数动态构建骆驼路由。我们有建立所有骆驼路线的泛型类。一些参数仅作为原始Camel Spring XML提供。该构建骆驼路由类扩展和RouteBuilder这里是代码构建骆驼路线的一部分：

@Override 
    public void configure() throws Exception { 
     RouteDefinition route = from(inputFile); 
     configureSpringXMLActivity(0, route, convertBodyXml); 
     configureSpringXMLActivity(5, route, setHeaderXml); 
    } 

    void configureSpringXMLActivity(final Integer seq, final RouteDefinition route, final String xmlConfig) 
      throws Exception { 
     ActivityIdentifier identifier = new CamelActivityIdentifier(seq); 
     route.process(new ActivityHandoverProcessor(identifier)); 
     final ChoiceDefinition choice = route.choice().when(new ActivityPredicate(identifier)); 

     RouteContext routeContext = new DefaultRouteContext(camelContext, route, route.getInputs().get(0), 
       camelContext.getRoutes()); 

     final StringReader reader = new StringReader(xmlConfig); 
     Object result = esb.getConfigUnmarshaller().unmarshal(reader); 
     if (result != null) { 
      ProcessorDefinition<?> processorDefinition = (ProcessorDefinition<?>) result; 
      Processor processor = processorDefinition.createProcessor(routeContext); 
      choice.process(processor); 
     } 

其中

/** setHeader xml. */ 
    private final String setHeaderXml = "<setHeader headerName=\"extractFileName\" xmlns=\"http://camel.apache.org/schema/spring\"><simple>${body}</simple></setHeader>"; 

    /** convertBody xml. */ 
    private final String convertBodyXml = "<convertBodyTo xmlns=\"http://camel.apache.org/schema/spring\" type=\"java.lang.String\"/>"; 

当我们开始骆驼上下文它产生于创建处理器的setHeader例外。

java.lang.ClassCastException: org.apache.camel.model.ProcessDefinition cannot be cast to org.apache.camel.model.SetHeaderDefinition 
    at org.apache.camel.management.DefaultManagementObjectStrategy.getManagedObjectForProcessor(DefaultManagementObjectStrategy.java:355) 
    at org.apache.camel.management.DefaultManagementLifecycleStrategy.getManagedObjectForProcessor(DefaultManagementLifecycleStrategy.java:515) 
    at org.apache.camel.management.DefaultManagementLifecycleStrategy.getManagedObjectForService(DefaultManagementLifecycleStrategy.java:467) 
    at org.apache.camel.management.DefaultManagementLifecycleStrategy.onServiceAdd(DefaultManagementLifecycleStrategy.java:378) 
    at org.apache.camel.impl.RouteService.startChildService(RouteService.java:338) 
    at org.apache.camel.impl.RouteService.warmUp(RouteService.java:182) 
    at org.apache.camel.impl.DefaultCamelContext.doWarmUpRoutes(DefaultCamelContext.java:3496) 
    at org.apache.camel.impl.DefaultCamelContext.safelyStartRouteServices(DefaultCamelContext.java:3426) 
    at org.apache.camel.impl.DefaultCamelContext.doStartOrResumeRoutes(DefaultCamelContext.java:3203) 
    at org.apache.camel.impl.DefaultCamelContext.doStartCamel(DefaultCamelContext.java:3059) 
    at org.apache.camel.impl.DefaultCamelContext.access$000(DefaultCamelContext.java:175) 
    at org.apache.camel.impl.DefaultCamelContext$2.call(DefaultCamelContext.java:2854) 
    at org.apache.camel.impl.DefaultCamelContext$2.call(DefaultCamelContext.java:2850) 
    at org.apache.camel.impl.DefaultCamelContext.doWithDefinedClassLoader(DefaultCamelContext.java:2873) 
    at org.apache.camel.impl.DefaultCamelContext.doStart(DefaultCamelContext.java:2850) 
    at org.apache.camel.support.ServiceSupport.start(ServiceSupport.java:61) 
    at org.apache.camel.impl.DefaultCamelContext.start(DefaultCamelContext.java:2819) 

在骆驼（版本2.17.0）的源代码 - 类DefaultManagementObjectStrategy：

.......... 
    } else if(target1 instanceof SetHeaderProcessor) { 
        answer = new ManagedSetHeader(context, (SetHeaderProcessor)target1, (SetHeaderDefinition)definition); 
......... 

铸造失败时（SetHeaderDefinition）定义

但是，我的第一个活动没有任何问题 - convertBodyXml。在同一骆驼类：

if(target1 instanceof ConvertBodyProcessor) { 
        answer = new ManagedConvertBody(context, (ConvertBodyProcessor)target1, definition); 

在这种情况下，骆驼代码并不需要转换定义来创建管理对象：......，定义）

DefaultManagementObjectStrategy该类创建一些管理铸造时的具体定义客体，而不是其他人。

请问您能否推荐如何解决ClassCastException，但仍然从通用ProcessorDefinition对象中构建路由。

在此先感谢。

Answer 1

而是从ProcessorDefinition上ChoiceDefinition构建Processor和呼叫处理方法，有可能只是ChoiceDefinition直接调用addOutput法ProcessorDefinition参数。

基本上，choice.addOutput(processorDefinition);

这里被更新的代码片段：

@Override 
    public void configure() throws Exception { 
     RouteDefinition route = from(inputFile); 
     configureSpringXMLActivity(0, route, convertBodyXml); 
     configureSpringXMLActivity(5, route, setHeaderXml); 
    } 

    void configureSpringXMLActivity(final Integer seq, final RouteDefinition route, final String xmlConfig) 
      throws Exception { 
     ActivityIdentifier identifier = new CamelActivityIdentifier(seq); 
     route.process(new ActivityHandoverProcessor(identifier)); 
     final ChoiceDefinition choice = route.choice().when(new ActivityPredicate(identifier)); 


     final StringReader reader = new StringReader(xmlConfig); 
     Object result = esb.getConfigUnmarshaller().unmarshal(reader); 
     if (result != null) { 
      ProcessorDefinition<?> processorDefinition = (ProcessorDefinition<?>) result; 
      choice.addOutput(result); 
     } 

我希望这会帮助别人