Aperture Overview

Administrators: Christiaan Fluit & Leo Sauermann

Source Code: Interfaces and standard implementations of Aperture

Project name

From ​Merriam-Webster Online:

Main Entry: ap·er·ture (sounds like ​this)
Pronunciation: 'ap-&(r)-"chur, -ch&r, -"tyur, -"tur
Function: noun
Etymology: Middle English, from Latin apertura, from apertus, past participle of aperire to open
1 : an opening or open space : HOLE
2 a : the opening in a photographic lens that admits the light b : the diameter of the stop in an optical system that determines the diameter of the bundle of rays traversing the instrument c : the diameter of the objective lens or mirror of a telescope

Features

• Easy to use: easy to learn, easy to code, easy to deploy in industrial projects
• Extract fulltext from many common file formats and information systems like IMAP email servers
• Extract metadata like author, date, subject and more from the data sources and file formats
• Open data objects for viewing
• Fully configurable framework, storing and editing config files is done through a SWING gui
• Pluggable architecture: can be easily extended, can be easily integrated to other projects
• Architecture based on industry standard OSGI
• Compatible with RDF, but not solely based on it

Components

• DataSource interface
• DataSource implementations for file systems, websites (or rather hypertextual sources in general) and IMAP servers
• Near future work: OutlookSource, MozillaSource/ThunderbirdSource

• DataAccessor interface
• DataAccessor implementations for file, http(s) and imap schemes

• DataCrawler interface
• One basic DataCrawler implementation for every DataSource type
• Later maybe more specialized DataCrawler implementations, e.g. a WindowsFileSystemCrawler with OS-specific optimizations

• Extractor interface
• Extractor implementation for everything we can easily support: PDF, Word, Excel, HTML, plain text, ...
• New domain for us but also probably very doable: PNG, JPG, AVI, ...

• ArchiveExtractor interface
• ArchiveExtractor implementations for Zip and Gzip

• LinkExtractor interface
• LinkExtractor implementation for HTML and XHTML
• Later maybe PDF, Flash, ...

• MimetypeIdentifier interface
• Badic MimeTypeIdentifer implementation based on magic numbers; absolute necessity for choosing the right Extractor, LinkExtractor or ArchiveExtractor implementation for a given file

• ​OSGi bindings and connector code (can be realized so that code is also usable outside an OSGi-based application)
• Configuration gui (what needs to be configured? isn't this very application-specific?)
• Sample GUI appication showing how to use it. Can also be used as test application, e.g. when you are developing new Extractor implementations.
• Metadata format descriptions (RDFS schema) and example metadata files

Supported File Formats

Right from the beginning we will support these file formats:

• Plain text
• HTML
• XML
• PDF (Portable Document Format)
• RTF (Rich Text Format)
• Microsoft Word 97+
• Microsoft Excel 97+
• Microsoft Powerpoint 97+
• Microsoft Works
• OpenOffice 1.0+: Writer, Calc, Impress, Draw
• StarOffice 6.0+: Writer, Calc, Impress, Draw
• OpenDocument (OpenOffice 2.0+)
• WordPerfect 5.x
• Emails (.eml files)