topic XML metadata extraction in Alfresco Archive

XML metadata extraction

swithun — Thu, 22 Apr 2010 14:20:38 GMT

I know this question gets asked a lot, and I've read the other threads, but without success. Most other people seemed to be trying to get XML metadata extraction within the web content management system. I don't know if my situation is significantly different.I would like to be able to import multip

Re: XML metadata extraction

derek — Thu, 22 Apr 2010 17:39:13 GMT

Hi,

At first glance, your config looks correct. Where have you placed your *-context.xml files?
Do you get interesting stuff when you turn on debug?
log4j.logger.org.alfresco.repo.content.metadata.xml=DEBUG

Regards

Re: XML metadata extraction

swithun — Fri, 23 Apr 2010 09:50:33 GMT

My *-context.xml files are in /opt/alfresco/tomcat/shared/classes/alfresco/extension/, as is my model document. I think this is the right place for them.

When I turn on debugging, this is all that I get on startup:


10:15:06,981  DEBUG [metadata.xml.XPathMetadataExtracter] Added mapping from rpsDate to /TEI.2/teiHeader/fileDesc/publicationStmt/date/text()
10:15:06,982  DEBUG [metadata.xml.XPathMetadataExtracter] Added mapping from rpsSession to /TEI.2/teiHeader/fileDesc/editionStmt/edition[@n='session']/text()
10:15:06,982  DEBUG [metadata.xml.XPathMetadataExtracter] Added mapping from rpsReign to /TEI.2/teiHeader/fileDesc/titleStmt/title/text()
10:15:06,983  DEBUG [metadata.xml.XPathMetadataExtracter] Added mapping from rpsID to /TEI.2/@id
10:15:06,992  DEBUG [metadata.xml.XPathMetadataExtracter] Added mapping from version to /model/version/text()
10:15:06,992  DEBUG [metadata.xml.XPathMetadataExtracter] Added mapping from author to /model/author/text()
10:15:06,993  DEBUG [metadata.xml.XPathMetadataExtracter] Added mapping from description to /model/description/text()
10:15:06,993  DEBUG [metadata.xml.XPathMetadataExtracter] Added mapping from title to /model/@name
10:15:06,999  WARN  [springframework.beans.GenericTypeAwarePropertyDescriptor] Invalid JavaBean property 'overwritePolicy' being accessed! Ambiguous write methods found next to actually used [public void org.alfresco.repo.content.metadata.AbstractMappingMetadataExtracter.setOverwritePolicy(java.lang.String)]: [public void org.alfresco.repo.content.metadata.AbstractMappingMetadataExtracter.setOverwritePolicy(org.alfresco.repo.content.metadata.MetadataExtracter$OverwritePolicy)]
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This indicates that my custom stuff is being picked up. There isn't any more output if I ingest an XML document (and add the aspect which defines the custom metadata fields and run the extract common metadata action). Could the WARNing message be relevant? It has always been there, even before I started trying to customise things. And commenting out the offending bean property makes no difference, apart from removing the log file entry.

Namespace issues are always complicated. I have a NS defined for my custom aspect, type and metadata fields. But the actual documents I want to ingest have no namespace defined, not even an empty one.

I have read posts saying that you need to comment out metadataExtracterRegistry property of the avmMetadataExtracter bean. I've tried this, with no effect.

Thanks for the quick reply. I'm sure I'm very close.

Re: XML metadata extraction

derek — Fri, 23 Apr 2010 11:25:02 GMT

Hi,
The problem must lie with the wcm-xml-metadata-extracter-context.xml file, which is specifically tailored to work with WCM. I'm guessing that the registry used there is not the correct one.

Re: XML metadata extraction

swithun — Wed, 12 May 2010 09:02:41 GMT

In the end, I got what I wanted by writing a pair of Java classes. One extends org.alfresco.repo.content.metadata.AbstractMappingMetadataExtracter, and is registered as a bean in content-services-context.xml. The other extends org.xml.sax.helpers.DefaultHandler, and is called by the first to parse the XML files and return a HashMap of metadata properties which can then be put into rawProperties using putRawValue.

Probably not the most elegant way, but it works.

Re: XML metadata extraction

derek — Wed, 12 May 2010 10:26:39 GMT

@swithum
It seems elegant to me! The generalized XML metadata extraction is quite nasty; I imagine that extracting specific values based on your expected XML is much neater - and deterministic.
Regards