Difference between revisions of "SMILA/Documentation/TikaPipelet"

Revision as of 04:21, 14 January 2013

This pipelet is not yet available in our repository. We are currently in the process of creating CQs for required third party components and hopefully get permission to use it in our project.

Bundle: org.eclipse.smila.tika

Description

The TikaPipelet converts various document formats (such as PDF, Microsoft Office formats, OpenOffice formats, etc.) to plain text using Tika technology: A binary attachment content can thus be converted to plain text and stored in an attribute. In addition to that, metadata properties of the document (like title, author, etc) can be extracted and written to record attibutes. To improve the Tika parsing process it is possible to optionally pass the content-type and filename of the document stored in other Record attributes via parameters contentTypeAttribute and fileNameAttribute.

The TikaPipelet supports the configurable error handling as described in SMILA/Development_Guidelines/How_to_write_a_Pipelet#Implementation. When used in jobmanager workflows, records causing errors are dropped.

Supported document types

By default, SMILA contains only a subset of Tika that supports the conversion of:

• plain text documents
• HTML/XML documents
• RTF documents
• Microsoft Office documents
• OpenOffice documents (OpenDocument formats)

See below on hints how to add Tika extractors for further formats

Configuration

Configuring the Property Mapping

In addition to the plain text content, Tika can extract metadata properties from documents like title, author, publisher, dates of publication etc, ... The names of these properties depend very much on the documents and what is actually extracted. Some well known names like Dublin Core (dc, dcterms) are used. For a complete list please refer to the Tika documentation. To check with your documents you can download Tika and use the Tika Application to see all extracted metadata.

To store such metadata properties in SMILA records, you must specify the names of the properties you want to store in the extractProperties parameter. Usually this parameter contains a sequence of maps. The map values have the following format:

Example

The following example shows how to configure the pipelet to extract the text from the attachment called Content and stores the extracted text in the attribute Text. Additionally the eventually contained metadata properties Company, Creator and Title will be stored in properties.

E.g. if a word document with the value "ACME" as company and "John Doe" as creator, the resulting record would contain the plain text in the attribute Text, the value ACME in the attribute Company, as well as the value John Doe in an attribute Creator.

<proc:configuration>
  <rec:Val key="inputName">Content</rec:Val>
  <rec:Val key="inputType">ATTACHMENT</rec:Val>
  <rec:Val key="outputName">Text</rec:Val>
  <rec:Val key="outputType">ATTRIBUTE</rec:Val>
  <rec:Val key="contentTypeAttribute">MimeType</rec:Val>
  <rec:Val key="fileNameAttribute">FileName</rec:Val>
  <rec:Val key="exportAsHtml">false</rec:Val>
  <rec:Val key="pageBreak">falsec</rec:Val>
  <rec:Val key="keepHyphens">false</rec:Val>
  <rec:Val key="maxLength">100000</rec:Val>
  <rec:Seq key="extractProperties">					    
     <rec:Map>					    
        <rec:Val key="metadataName">company</rec:Val>
        <rec:Val key="targetAttribute">Company</rec:Val>			    					    
        <rec:Val key="singleResult">false</rec:Val>			    					    
     </rec:Map>
     <rec:Map>					    
        <rec:Val key="metadataName">creator</rec:Val>
        <rec:Val key="targetAttribute">Creator</rec:Val>			    					    
        <rec:Val key="singleResult">false</rec:Val>			    					    
     </rec:Map>
     <rec:Map>					    
        <rec:Val key="metadataName">title</rec:Val>
        <rec:Val key="targetAttribute">Title</rec:Val>			    					    
        <rec:Val key="singleResult">true</rec:Val>			    					    
     </rec:Map>		
  </rec:Seq>
</proc:configuration>

Typical Property-Names

• Generic
  • "contributor"
  • "coverage"
  • "creator"
  • "description"
  • "format"
  • "identifier"
  • "language"
  • "modified"
  • "publisher"
  • "relation"
  • "rights"
  • "source"
  • "subject"
  • "title"
  • "type"

• MS- Office
  • "Application-Name"
  • "Application-Version"
  • "Author"
  • "Category"
  • "Comments"
  • "Company"
  • "Content-Status"
  • "Edit-Time"
  • "Keywords"
  • "Last-Author"
  • "Manager"
  • "Notes"
  • "Presentation-Format"
  • "Revision-Number"
  • "Security"
  • "Template"
  • "Total-Time"
  • "custom:"
  • "Version"

Extending Tika

SMILA does not contain the complete Tika distribution, because some converters need third party libraries with problematic licenses that we are not allowed to distribute. However, it should be easy to include those parts of Tika into your SMILA installation yourself:

TODO