Group items tagged

 ActionScript 3 Reflection API

describeType

method returns

Mapping JPA Entities To SQL View

return a different “view” to the client

Especially in the context of pagination, where the data is mostly retrieved for read-only purposes, database views are the easier and more efficient alternative. Instead of implementing a lot of plumbing on the “Java-side” all the work could be easily done in the database

differences between CDI beans and EJBs is that EJBs are : Transactional Remote or local Able to passivate stateful beans freeing up resources Able to make use of timers Can be asynchronous

Stateless EJBs can be thought of as thread safe single-use beans that don’t maintain any state between two web requests

Stateful EJBs do hold state and can be created and sit around for as long as they are needed until they are disposed of

Entity-Control-Boundary (ECB) architectural pattern matches perfectly with our pattern language

domain structure is an Entity, the Control is a service, and the Boundary is realized with a facade

In simpler cases the facade and service can collapse, and a service would be realized only as a facade's method in that case

DAOs aren't dead, but they cannot be considered as a general best practice any more. They should be created in a bottom-up, rather than a top-down, fashion. If you discover data-access code duplication in your service layer, just factor it out to a dedicated DAO and reuse it. Otherwise it is just fine to delegate to an EntityManager from a service. The enforcement of an empty DAO layer is even more harmful, because it requires you to write dumb code for even simple use cases. The more code is produced, the more time you must spend to write tests and to maintain it.

With JDK 1.5 and the advent of generics, it is possible to build and deploy a generic, convenient, and typesafe DAO once and reuse it from variety of services

key ingredients of a service-oriented component: Facade: Provides simplified, centralized access to the component and decouples the client from the concrete services. It is the network and transaction boundary. Service: The actual implementation of business logic. Domain structure: This is a structure rather than an object. It implements the component's persistence and exposes all of its state to the services, without encapsulation.

This convention not only standardizes the structure and improves maintainability, but also allows automatic dependency validation with frameworks like JDepend, Checkstyle,  Dependometer, SonarJ, or XRadar. You can even perform the validation at build time. If you do, the continuous build would break on violation of defined dependencies. The rules are clearly defined with strict layering: a facade may access a service, and the service a domain object, but not vice versa

Arquillian Testing Framework

Arquillian is an integration and functional testing platform that can be used for Java middleware testing. With the main goal of making integration (and functional) tests as simple to write as unit tests, it brings the tests to the runtime environment, freeing developers from managing the runtime from within the test.