Originally Tentackle has been developed for scientific and technical applications, where running the same domain logic not only in intermediate tiers but also at remote sites very often is an irrevocable requirement. However, business applications can benefit from its architecture as well, especially multi-tier Java FX desktop applications.
The Persistent Domain Object
A persistent domain object (PDO) combines persistence- and domain-related features. However, Tentackle PDOs are not ordinary POJOs but POJIs: Plain Old Java Interfaces.
The PDO’s interface extends a persistence- and a domain-interface, that are implemented separately without any dependency to each other. This design brings the best of both worlds, the rich and the anemic domain model: implement the domain- and persistence logic within the same OO hierarchy, but keep them strictly separated!
Distributed by design
Since entities and operations travel freely between JVMs, the ubiquitous language is available in all tiers.
Tentackle is a modular framework from the ground up leveraging the features introduced with Java 9 (Jigsaw).
Applications are developed against interfaces, not implementations. Especially the precious domain logic does not depend on the persistence implementation.
Maven Plugins and Wizards
Tentackle provides several maven plugins to ease the development process. PDO and Operation wizards create the interfaces and implementations within the blink of an eye.
Tentackle’s maven jlink plugin creates self-contained Java applications. No need for system-wide Java installations anymore. The plugin can be used for any kind of java application, not only Tentackle apps, even non-modularized or mixed.
The domain model is defined in comment blocks right within the sources. During the maven build the model is parsed and the source code generated or updated accordingly.
No bytecode voodoo
There is no bytecode instrumentation and no classpath scanning. All necessary steps to analyze the application are performed at build time, thus reducing the startup time significantly.
Tentackle provides an auto-update feature. Once installed the application automatically updates itself whenever a new version becomes available.
PDOs can be immutable. For example, a component PDO not loaded from within its aggregate root’s domain context is automatically immutable.
Snapshots of entities, aggregates or parts of them provide a kind of “transactions in memory”. With snapshots it’s very easy to implement undo operations, for example.
Tentackle has been successfully used in many projects, mainly technical and scientific applications. During the years it has gone through several redesigns and major refactorings. Eventually, it became Open Source for “those who where interested”. Since 2016 the sources are hosted at Bitbucket and the artifacts are available from Maven Central. Finally, in 2020 we felt that Tentackle has reached a level of maturity, usability and well working tooling to introduce it to a broader public.