Eobject.org's open-source Java framework MetaModel implements a unified API for the access, exploration, and query of different datastores. It supports a spectrum of different persistence providers such as relational databases, XML files, or Excel spreadsheets.
The Java-based datastore engine mainly focuses on reusability and is provided under LPGL licence. Eobjects.org, both a website and an open source software organization dedicated to “the development of Open Source software related to Business Intelligence and Data Warehousing”, has recently published version 1.5 of MetaModel with features structured into three areas:
- Better compliance with datastores such as inclusion of Excel 2007 as a new datastore type, support of composite datastores, and Excel formula calculation.
- A Query Builder API offering a new layer of abstraction on top of the existing Query API in order to hide complexity and reduce programming errors.
- Emphasis on interfaces and immutability, i.e., almost all parts of the library are provided as interfaces for better testability, integration and deployment, and safety is addressed by exposing only immutable variants of data structures.
The coarse grained architecture of MetaModel is:
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MetaModel is used in applications such as the data ware house generation system Quipu, and the open source data profiling application DataCleaner which also denotes a project of eobjects.org.
The open source directory ohloh evaluates MetaModel with a high community rating, but also mentions that MetaModel was implemented by a single active developer, Kasper Sørensen.
Recently, the company Human Inference has acquired eobjects.org as published in a press announcement.
According to eobjects.org
all projects of eobjects.org, including MetaModel, will remain Open Source, but heavily enforced by the invested time and resources that Human Inference is adding to these projects.
Interested software engineers may obtain MetaModel 1.5 via the organization’s download site.