Question

I need to post a JSON Camel Servlet, then duplicate the message and split the list. Process each splitted message and finally aggregate and return the servlet response.

However, as soon as the splitter is introduced in the route, I see the Input Stream is being closed and the Servlet cannot write the response back.

Please note that stream caching is enabled as well.

from("servlet:sample")
                .log(LoggingLevel.INFO, "Message Received: JSON RQ")
                .to("direct:samplejson");
from("direct:samplejson")
    .streamCaching()
    .setHeader("sampleId", simple("${id}"))
    .log(LoggingLevel.INFO, SampleID in Header: ${header.sampleId}")
    .unmarshal().json(JsonLibrary.Jackson, Sample.class)
    .log(LoggingLevel.INFO, "Converted to JSON: ${body.toString}")
    .process("sampleProcessor")
    .split().body().streaming()
        .choice()
        .when().method("sampleProcessor", "isTypeA")
            .marshal().jacksonxml(Sample.class)
        .endChoice()
        .otherwise()
            .marshal().jacksonxml(Sample.class)
    .end()
    .aggregate(SampleAggregationStrategy).header("sampleId").completionSize(2).completionTimeout(1000L)
    .to("direct:samplexml");
from("direct:samplexml").marshal().jacksonxml(List.class).log("FINISHED PROCESSING");

Exception:

2017-06-12 12:22:25,311 [apr-8080-exec-2] INFO  route1                         - FINISHED PROCESSING
2017-06-12 12:22:25,321 [apr-8080-exec-2] ERROR CamelHttpTransportServlet      - Error processing request
java.io.IOException: Stream closed
        at org.apache.catalina.connector.InputBuffer.read(InputBuffer.java:372) ~[catalina.jar:8.0.30]
        at org.apache.catalina.connector.CoyoteInputStream.read(CoyoteInputStream.java:156) ~[catalina.jar:8.0.30]
        at org.apache.camel.util.IOHelper.copy(IOHelper.java:196) ~[camel-core-2.19.0.jar:2.19.0]
        at org.apache.camel.http.common.DefaultHttpBinding.copyStream(DefaultHttpBinding.java:432) ~[camel-http-common-2.19.0.jar:2.19.0]
        at org.apache.camel.http.common.DefaultHttpBinding.doWriteDirectResponse(DefaultHttpBinding.java:496) ~[camel-http-common-2.19.0.jar:2.19.0]
        at org.apache.camel.http.common.DefaultHttpBinding.doWriteResponse(DefaultHttpBinding.java:395) ~[camel-http-common-2.19.0.jar:2.19.0]
        at org.apache.camel.http.common.DefaultHttpBinding.writeResponse(DefaultHttpBinding.java:322) ~[camel-http-common-2.19.0.jar:2.19.0]
        at org.apache.camel.http.common.CamelServlet.doService(CamelServlet.java:210) [camel-http-common-2.19.0.jar:2.19.0]
        at org.apache.camel.http.common.CamelServlet.service(CamelServlet.java:74) [camel-http-common-2.19.0.jar:2.19.0]
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:729) [servlet-api.jar:?]
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291) [catalina.jar:8.0.30]
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) [catalina.jar:8.0.30]
        at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) [tomcat-websocket.jar:8.0.30]
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) [catalina.jar:8.0.30]
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) [catalina.jar:8.0.30]
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212) [catalina.jar:8.0.30]
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106) [catalina.jar:8.0.30]
        at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502) [catalina.jar:8.0.30]
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141) [catalina.jar:8.0.30]
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) [catalina.jar:8.0.30]
        at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616) [catalina.jar:8.0.30]
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88) [catalina.jar:8.0.30]
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:521) [catalina.jar:8.0.30]
        at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1096) [tomcat-coyote.jar:8.0.30]
        at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:674) [tomcat-coyote.jar:8.0.30]
        at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2500) [tomcat-coyote.jar:8.0.30]
        at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2489) [tomcat-coyote.jar:8.0.30]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [?:1.8.0_74]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [?:1.8.0_74]
        at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-util.jar:8.0.30]
        at java.lang.Thread.run(Thread.java:745) [?:1.8.0_74]

If I remove the splitter and aggregator, I see the Servlet response coming back.

Many Thanks in advance for all the help provided!.

Answer 1

请参阅堆肥消息处理器EIP模式（http://camel.apache.org/composed-message-processor.html）和仅使用拆分器的示例，它允许您在同一工作单元中执行fork / join，并且能够在servlet中返回响应。仅拆分器支持AggregationStrategy，您可以配置聚合响应的位置。换句话说，不要同时使用拆分器和聚合器，而只使用拆分器。

Apache camel servlet stream closed after split()

1 个答案: