Group items tagged

Entity–attribute–value model

Entity–attribute–value model (EAV) is a data model to describe entities where the number of attributes (properties, parameters) that can be used to describe them is potentially vast, but the number that will actually apply to a given entity is relatively modest

also known as object–attribute–value model, vertical database model and open schema

CDI + JPA + EJB + JTA + JSF: Login quickstart

displayed using JSF views, business logic is encapsulated in CDI beans, information is persisted using JPA, and transactions can be controlled manually or using EJB

Deploying the Login example using Eclipse

Dependency Injection in Java EE 6 - Part 1

high-level look at CDI, see how it fits with Java EE overall and discuss basic dependency management as well as scoping.

CDI is designed to solve

Java EE 7 Roadmap

support for use in cloud environments

Web Sockets

think in structs. Try to as frictionless as possible export/generate the JPA-entities from the existing database

Implement a very thin facade / transaction boundary

@Stateless Bean (EJB 3)

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

In JEE the EntityManager or EntityManagerFactory can

injected into a SessionBean

A managed EntityManager should never be closed, and integrates with JTA transactions

used for: Strategy Pattern: there are already several implementations of an algorithm or concept Layering: there is a clear need to hide e.g. an ugly implementation of a legacy framework API (not very common): you have to expose a API, which gets implemented by SPI (e.g. JDBC)

EJB beans cannot be directly exposed to JSF or JSP without a little help from CDI

CDI doesn't provide any transactional, monitoring, or concurrency aspect out of the box

stateless EJB 3.1 bean as boundary (Facade)

boundary, which main responsibilities are:Providing coarser granularityEnsuring consistencyProviding a defined entry point which can be easily decorated with aspects / interceptorsExposure of components (what components are we will cover later) functionality to remote clients via IIOP, REST, SOAP, JMS, Hessian etc...

ServiceFacade - the facade to Services. The Services just rely on a certain amount of cross cutting aspects and concentrate on the realization of business logic

only invokes Services in consistent way, mostly using transactions

What Is The @Interceptors Overhead?

two, empty, interceptors

TypeAverageMinMaxTransactions/Sec Plain EJB 3.11082833.66 Intercepted EJB 3.11092818.88

In fact people still love those books without realizing that the world has changed dramatically ever since

The reality check here is to wonder whether the rhetorics set forth by Rod Johnson in his 2003/2004 books are still actual today

So if you still care about those books, the best way to show your appreciation is probably to use them as your monitor stand

TomEE is a superset of OpenEJB

Tomcat

TomEE

Set break points in my Java code Start up the Java application server with the appropriate debug JVM properties set (e.g. -Xdebug -Xrunjdwp:transport=dt_socket,address=8000,server=y,suspend=n) From Eclipse, I attach a remote debugger to the app server on the default port 8000. The Java Debugger will open up when a break point is hit. Set breakpoints in my Flex application (or one of its modules). From Eclipse (with Flash Builder) I launch a debug configuration for my Flex app. The Flex Debugger will open up when a break point is hit. At this point I have two debuggers open and everything work great. Two other things I do: a) extend the transaction system timeout, so it doesn't get trigger while I am sitting there think for a few minutes b) use Charles Proxy (in reverse proxy mode) inbetween the client and server to watch the AMF traffic and view payloads, etc.