Question

我们根据存储在数据库中的配置参数动态构建camel路由。我们有通用类来构建所有驼峰路由。一些参数只是作为原始Camel Spring XML呈现。构建camel路由的类扩展了RouteBuilder，这里是构建Camel路由的代码的一部分：

@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\"/>";

当我们启动camel上下文时，它会在创建setHeader处理器时产生异常。

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Camel（版本2.17.0）中源代码 - 类DefaultManagementObjectStrategy：

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

在转换（SetHeaderDefinition）定义

时失败

然而，我的第一个活动 - convertBodyXml没有问题。在同一个Camel类中：

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

在这种情况下，Camel代码不需要转换定义来创建托管对象：...，定义）

DefaultManagementObjectStrategy类在创建某个托管对象时执行特定定义，但在其他托管对象上没有。

请问您如何绕过ClassCastException，但仍然可以从通用的ProcessorDefinition对象构建路由。

提前致谢。

Answer 1

不是从Processor构建ProcessorDefinition并在ChoiceDefinition上调用流程方法，而是可以在{{addOutput参数上调用ProcessorDefinition方法1}}直接。

基本上，ChoiceDefinition

这是更新的代码段：

choice.addOutput(processorDefinition);

我希望它会帮助某人

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

1 个答案: