Mule ESB选择流控路由

Question

在 Mule 中，我有以下流程： 有一个选择流控制来测试输入并验证输入字符串是否等于'ctr1'。

    <flow name="mediationFlow1" doc:name="mediationFlow1">
         <file:inbound-endpoint path="C:\MuleStudio\SandBox\input" pollingFrequency="3000" responseTimeout="10000" doc:name="File"/>
        <file:file-to-string-transformer doc:name="File to String"/>
        <choice doc:name="Choice">
            <when expression="payload=='ctr1'">
                <cxf:jaxws-client operation="find" serviceClass="services.port.PortWS" port="portWSPort" enableMuleSoapHeaders="true" doc:name="Port"/>
                <http:outbound-endpoint exchange-pattern="request-response" method="POST" address="http://localhost:8080/Actors/portWS" doc:name="portWS"/>
            </when>
            <otherwise >
                <cxf:jaxws-client operation="find" serviceClass="services.douane.DouaneWS" port="douaneWSPort" enableMuleSoapHeaders="true" doc:name="Douane"/>
                <http:outbound-endpoint exchange-pattern="request-response" method="POST" address="http://localhost:8080/Actors/douaneWS" doc:name="douaneWS"/>
            </otherwise>
        </choice>
       <file:outbound-endpoint path="C:\MuleStudio\SandBox\output" outputPattern="#[function:datestamp:dd-MM-yy]_#[function:systime].xml " responseTimeout="10000" doc:name="Outgoing File"/>
    </flow>
</mule>

当我单独运行它们时，这两个 Web 服务调用都可以完美运行，但是当我添加选项 ccontrol 时，这就是我得到的：

INFO  2013-05-14 15:48:07,892 [[mediation].connector.file.mule.default.receiver.01] org.mule.transport.file.FileMessageReceiver: Lock obtained on file: C:\MuleStudio\SandBox\input\input.txt
INFO  2013-05-14 15:48:08,206 [[mediation].mediationFlow1.stage1.02] org.mule.transport.service.DefaultTransportServiceDescriptor: Loading default outbound transformer: org.mule.transport.http.transformers.ObjectToHttpClientMethodRequest
INFO  2013-05-14 15:48:08,216 [[mediation].mediationFlow1.stage1.02] org.mule.transport.service.DefaultTransportServiceDescriptor: Loading default response transformer: org.mule.transport.http.transformers.MuleMessageToHttpResponse
INFO  2013-05-14 15:48:08,253 [[mediation].mediationFlow1.stage1.02] org.mule.transport.service.DefaultTransportServiceDescriptor: Loading default outbound transformer: org.mule.transport.http.transformers.ObjectToHttpClientMethodRequest
INFO  2013-05-14 15:48:08,254 [[mediation].mediationFlow1.stage1.02] org.mule.lifecycle.AbstractLifecycleManager: Initialising: 'connector.http.mule.default.dispatcher.7073225'. Object is: HttpClientMessageDispatcher
INFO  2013-05-14 15:48:08,260 [[mediation].mediationFlow1.stage1.02] org.mule.lifecycle.AbstractLifecycleManager: Starting: 'connector.http.mule.default.dispatcher.7073225'. Object is: HttpClientMessageDispatcher
INFO  2013-05-14 15:48:09,035 [[mediation].connector.file.mule.default.dispatcher.01] org.mule.lifecycle.AbstractLifecycleManager: Initialising: 'connector.file.mule.default.dispatcher.23051110'. Object is: FileMessageDispatcher
INFO  2013-05-14 15:48:09,035 [[mediation].connector.file.mule.default.dispatcher.01] org.mule.lifecycle.AbstractLifecycleManager: Starting: 'connector.file.mule.default.dispatcher.23051110'. Object is: FileMessageDispatcher
INFO  2013-05-14 15:48:09,040 [[mediation].connector.file.mule.default.dispatcher.01] org.mule.transport.file.FileConnector: Writing file to: C:\MuleStudio\SandBox\output\14-05-13_1368539289037.xml
INFO  2013-05-14 15:48:09,043 [[mediation].connector.file.mule.default.dispatcher.01] org.mule.module.xml.transformer.jaxb.JAXBContextResolver: No common Object of type 'class javax.xml.bind.JAXBContext' configured, creating a local one for: SimpleDataType{type=services.port.Port, mimeType='text/xml'}, SimpleDataType{type=java.io.InputStream, mimeType='*/*'}
ERROR 2013-05-14 15:48:09,058 [[mediation].connector.file.mule.default.dispatcher.01] org.mule.exception.DefaultMessagingExceptionStrategy: 
********************************************************************************
Message               : An invalid return type "class java.io.InputStream" was specified for transformer "JAXBMarshallerTransformer"
Code                  : MULE_ERROR-266
--------------------------------------------------------------------------------
Exception stack is:
1. An invalid return type "class java.io.InputStream" was specified for transformer "JAXBMarshallerTransformer" (org.mule.api.transformer.TransformerException)
  org.mule.module.xml.transformer.jaxb.JAXBMarshallerTransformer:122 (http://www.mulesoft.org/docs/site/current3/apidocs/org/mule/api/transformer/TransformerException.html)
--------------------------------------------------------------------------------
Root Exception stack trace:
org.mule.api.transformer.TransformerException: An invalid return type "class java.io.InputStream" was specified for transformer "JAXBMarshallerTransformer"
    at org.mule.module.xml.transformer.jaxb.JAXBMarshallerTransformer.doTransform(JAXBMarshallerTransformer.java:122)
    at org.mule.transformer.AbstractTransformer.transform(AbstractTransformer.java:411)
    at org.mule.DefaultMuleMessage.getPayload(DefaultMuleMessage.java:362)
    + 3 more (set debug level logging or '-Dmule.verbose.exceptions=true' for everything)
********************************************************************************

我不确定它是否来自选择测试表达式？ 虽然我找不到太多关于如何详细使用选择控制流的信息。

感谢您的帮助。 谢谢。

Answer 1

默认情况下，Mule 在流中应用大量转换器将有效负载转换为所需的格式。

在没有选择路由器的情况下，它会将返回的对象转换为 xml 字符串以写入文件。 但是对于选择路由器，程序员有责任提供一个转换器来将响应对象转换为 XML 字符串。

在选择路由器之后和写入文件出站之前，将以下 mule-xml jaxb 对象添加到 xml 转换器。

 .....
    </otherwise>
 </choice>

 <xm:jaxb-object-to-xml-transformer name="ObjectToXML" jaxbContext-ref="MyJaxb"  returnClass="java.lang.String" encoding="UTF-8"/>

希望这会有所帮助。