带有Apache骆驼的多文件I / O

我的要求如下：我需要解压缩文件并从解压缩的xml文件中读取元数据信息。这将在中完成xmlToObjectMapper。现在，我需要使用位于zip文件中的多个其他xml的数据来丰富元数据。这意味着我必须将它们拆包阅读，然后将信息附加到我的MetadataHolder对象上。我想在注释行中实现这一点pollEnrich。

from("file://{{first.directory}}?noop=true&idempotent=true")
        .split(new ZipSplitter())
            .streaming()
                .choice()
                    .when(header("zipFileName").isEqualTo("metadata.xml"))
                        .multicast()
                            .to("file://{{first.directory}}/Working?fileName=$simple{file:onlyname.noext}/${header.zipFileName}")
                            .pipeline()
                                .convertBodyTo(String.class, StandardCharsets.ISO_8859_1.name())
                                .bean("xmlToObjectMapper", "readAllRequiredMetadata")
                                //.pollEnrich("", 0, new MetadataHolderAggregationStrategy())
                            .end()
                        .end()
                .end()
            .to("file://{{first.directory}}/Working?fileName=$simple{file:onlyname.noext}/${header.zipFileName}")
        .end()
    .end()
    ;

但是现在我被卡住了，因为我得到了以下堆栈跟踪：

org.apache.camel.InvalidPayloadException: No body available of type: java.lang.String but has value: org.apache.camel.dataformat.zipfile.ZipInputStreamWrapper@2c52254b of type: org.apache.camel.dataformat.zipfile.ZipInpu
tStreamWrapper on: Message[id]. Caused by: Error during type conversion from type: java.lang.String to the required type: java.lang.String with value [Body is instance of java.io.I
nputStream] due java.io.IOException: Stream closed. Exchange[id]. Caused by: [org.apache.camel.TypeConversionException - Error during type conversion from type: java.lang.String to
 the required type: java.lang.String with value [Body is instance of java.io.InputStream] due java.io.IOException: Stream closed]

我以为多播会隐式缓存流并将其发送到所有端点...

有人能告诉我为什么会这样吗？我对需求的解决方案是有效的方法还是必须将需求分为多条路线？

编辑1：

我通过添加.streamCaching()到路由解决了异常的问题。由于其他问题，我不得不稍微更改原始路线。

from("file://{{first.directory}}?noop=true&idempotent=true")
        .streamCaching()
        .split(new ZipSplitter())
            .streaming()
                .choice()
                    .when(header("zipFileName").isEqualTo("metadata.xml"))
                        .multicast()
                            .to("file://{{first.directory}}/Working?fileName=$simple{file:onlyname.noext}/${header.zipFileName}")
                            .pipeline()
                                .convertBodyTo(String.class, StandardCharsets.ISO_8859_1.name())
                                .bean("xmlToObjectMapper", "readAllRequiredMetadata")
                                .pollEnrich("file://{{second.directory}}?&noop=true&idempotent=true", 0, new MetadataHolderAggregationStrategy())
                            .end()
                        .end()
                    .endChoice()
                    .otherwise()
                        .to("file://{{first.directory}}/Working?fileName=$simple{file:onlyname.noext}/${header.zipFileName}")
                .end()
        .end()
    .end()
    ;

但是现在我遇到了问题pollEnrich。我的newExchangeMetadataHolderAggregationStrategy始终为null。我该如何解决？

编辑2：

终于我找到了解决方案。我必须使用enrich代替pollEnrich并在java（readAllRequiredMetadata2）中实现整个I / O。我的最终解决方案如下所示：

from("file://{{first.directory}}?noop=true&idempotent=true")
        .streamCaching()
        .split(new ZipSplitter())
            .streaming()
                .choice()
                    .when(header("zipFileName").isEqualTo("metadata.xml"))
                        .multicast()
                            .to("file://{{first.directory}}/Working?fileName=$simple{file:onlyname.noext}/${header.zipFileName}")
                            .pipeline()
                                .convertBodyTo(String.class, StandardCharsets.ISO_8859_1.name())
                                .bean("xmlToObjectMapper", "readAllRequiredMetadata")
                                .enrich("direct:readResources", 0, new MetadataHolderAggregationStrategy())
                                //Go on processing the enriched metadata
                            .end()
                        .end()
                    .endChoice()
                    .otherwise()
                        .to("file://{{first.directory}}/Working?fileName=$simple{file:onlyname.noext}/${header.zipFileName}")
                .end()
        .end()
    .end()
    ;

from("direct:readResources")
   .bean("xmlToObjectMapper", "readAllRequiredMetadata2")
.end()
;