Java EE (JSF (MVC Architecture (View (Composite component based (3rd Party…

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EJB3

Java EE

JSF

MVC Architecture

Model

View

Controller

JSF Engine

CDI Bean

Built using Facelet declaration language

xhtml page

Tags

Composite component based

Reusable snippet of code

Has various elements attached (e.g. bean validation)

Data bindings

3rd Party Pluggable component libraries

PrimeFaces

Apache MyFaces

ICEFaces

Navigation

Replaces values

The bound model

The bound view

Ajax

Supported out of the box

<f:ajax /> e.g. <f:ajax event="click" />

Facelet declaration language

HTML Tags (Not required - Can use HTML tags directly)

<h:form>

<h:inputText>

<h:commandButton>

<h:selectOneRadio>

<h:inputTextArea>

<h:outputText>

<h:commandLink>

Facelets Tags

<ui:composition>

<ui:insert>

<ui:repeat>

<ui:fragment>

<ui:debug>

<ui:decorate>

<ui:param>

<ui:define>

Repeat a section of code (i.e. loop)

Start a composite definition

Core Tags

<f:convert>

<f:convertDateTime>

<f:lengthvalidate>

<f:ajax>

<f:loadBundle>

<f:selectItem>

<f:actionListener>

CDI Scopes

for

Types

Dependent (default)

Not share between clients

Created and destroyed with the instance it belongs to

Determines which client refers to which instance of the bean

The scope of a bean determines the bean's lifecycle

ViewScope (@ViewScoped)

FlowScope (@FlowScoped)

FlowDefinition (@FlowDefinition)

Share the same lifecycle as the view which initially referenced them

Connect logically related pages together

Useful for views that make use of AJAX

Connect logically related pages together

Allow the bean lifecycle to be defined for a collection of views

JSF engine will find the view

Pass view name to the action of component

CDI

Annotations

@Produces

Mark the return value an "injectable" bean

@Inject

Mark the injection point

@Disposes

@Stereotype

Identifies the disposed parameter of a disposer method, which allows the application to perform customized clean-up of an object returned by a producer method/field

Combines a number of annotations that are repeatedly used in different places

@Named

Enables a bean to be accessible from EL

Injections

Inject by type

When type is not sufficient, use @Qualifier

Scopes

@RequestScoped

@ViewScoped

@FlowScoped

@Transaction

@SessionsScoped

@ConversationScoped

@Dependent

@CustomScoped

Bean lives as long as the HTTP request-response lives.

created upon a HTTP request

gets destroyed when the HTTP response associated with the HTTP request is finished

Bean lives as long as the user is interacting with the same JSF view in the browser window/tab

It gets created upon a HTTP request

gets destroyed once the user postbacks to a different view

Bean lives as long as the HTTP session lives

gets created upon the first HTTP request involving this bean in the session

gets destroyed when the HTTP session is invalidated

@ApplicationScoped

gets created upon the first HTTP request involving this bean in the application

Bean lives as long as the web application lives

gets destroyed when the web application shuts down.

Advanced scope. Usually used when extending CDI framework

Default scope

Interceptors

Decorator

Event Bus

Lightweight

Enables messages to be passed through the system in a very decoupled way

@Observes

Mark the event (e.g. a method parameter) to observe

Beans don't require to be marked with @Named annotation to be accessible in other part of the system. It is, however, required for them to be accessed in JSF

<f:viewParam>

Get parameter from query string

Expression language

#{not empty bean.attributeName}

EJB3

Attributes

Encapsulate business logic

Execute in container

Always run within a transaction

Container console shows data (e.g. response time) related to EJB currently running

Types

Session Bean

@Stateless

@Stateful

@Singleton

Message Driven Bean

Functions as an extension of the client - it holds distinct client client-related state data

1-1 relationship between client and bean e.g. 100 client connection means 100 instances of stateful bean in memory

Used when client state is required to be held

Can be shared among multiple clients

Attributes

Don't need to worry about how a message is delivered or consumed

It is just about messaging handling

Unlike Session bean, it cannot be accessed directly by client

Can only be interested with via message

Access modes

Specified via annotations

Types

Local (@Local)

only access within the same container

Thread safety - each EJB instance runs in a single thread context

Remote (@Remote)

Accessible from external applications

Web service

Accessible with a client using web service

Annotations

@Lock

Concurrency control

@AccessTimeout

@Transactional

@PermitAll

Every security roles are allowed to invoke the annotated method

@RolesAllowed

Specifies the security roles required to access the method

@Asychronous

Act as queue based

@Schedule

Execute using cron-style time schedule

@TransactionAttribute

Extension of the messaging system, representing endpoint functionality

Roles

Destination

Queue

Topic

Publisher/Sender

Subscriber/receiver/listener

Message

Has a payload that contains the request that needs to be passed

Types

TextMessage

ByteMessage

StreamMessage

ObjectMessage

MapMessage

Setup

Point-to-Point

Publisher/Receiver

Destinations are known as queue

Messages are delivered to a single receiver

Queues hold messages until it is processed by receiver

Destinations are known as topics

Messages are delivered (broadcast) to all registered subscribers

Topics don't hold messages

JPA

Data Modelling

Implementations

Hibernate

Toplink

Eclipselink

@Entity

@Id

@Generated

@Embeded

@OneToOne

@OneToMany

@ManyToOne

@ManyToMany

@Table

@Embeddable

@Column

@Enumerated

@Temperal

@Transient

@JoinColumn

@JoinTable

Bean validation

Annotations

Overview

Can validate

Bean's attribute

Parameter

Return value

Can be triggered by

JSF

JPA

CDI

JAX-RS

ValidatorFactory

@AssertTrue

@DecimalMax

Used to validate unmanaged POJO

@Future

@Max(100)

@NotNull

Used on boolean field

Used on date field

Exception is thrown if validation fails

@Pattern

Regular expression

@Size

Size of a field

@Digits