Spring framework

Workshop of Spring Application Framework at Capegemini

Presented By
Rajkumar Singh

www.rajkrrsingh.blogspot.com

Agenda

Introduction
Spring Architecture
Spring Beans
Spring IOC
Setting up Spring Environment
Beans Life cycles
Spring DAO
Spring ORM
Spring AOP
Q&A


Introduction
Spring framework was initially written by Rod Johnson and
was first released under the Apache 2.0 license in June
2003.

Primary purpose is to reduce the dependencies(loose
couple)

Spring deliver many significant benefits to the developers
reducing development effort and cost while improving test
coverage and quality

Handle the infrastructure so that developer can focus on
the development only

Enables you to build application from POJOs

Spring does not recreate all the framework but make use of
the existing one like ORM,logging,JEE framework.

What Spring Offers

Dependency Injection

Aspect Oriented Programming (AOP)

Portable Serives
ORM
DAO
MVC


Application Layering

Presentation Layer
Spring MVC
Spring Web Service Layer
Gateway to expose business logic to the outside world

Persistence Layer Not well defined in many applications today or tightly
coupled in an inappropriate layer.
JDBC
ORM Manages ‘container level services’ Eg. transactions,
security, data access logic, and manipulates domain objects

Domain Layer
POJOs


Spring Architecture


Spring Architecture

Core & Beans:
Provides fundamental functionality & Dependency Injection features.
Primary component is the BeanFactory (Factory pattern )

The Context module
Builds on the base modules.
Access objects in a framework-style manner similar to a JNDI registry.
Also supports Java EE features such as EJB, JMX ,and basic remoting.
The ApplicationContext interface is the focal point of the module.

The Expression Language module
Provides a powerful expression language for querying and
manipulating an object graph at runtime.


Spring Architecture
The JDBC module
a JDBC-abstraction layer that removes tedious
JDBC coding, parsing of database-vendor specific error codes.
The ORM module
integration layers for ORM APIs, including JPA, JDO, Hibernate, & iBatis.

The OXM module supports
Object/XML mapping implementations for JAXB, Castor, XMLBeans, JiBX and X

The JMS Module
contains features for producing and consuming messages.

The Transaction module supports
programmatic and declarative transaction management


Spring Architecture
Spring's Web module
provides basic web-oriented integration features
(multipart file-upload)
initialization of the IoC container using servlet listeners
Web Servlet
Spring's model-view-controller (MVC)

The Web-Struts module
contains Support classes for integrating a classic Struts web tier within
a Spring application.

The Web-Portlet module
provides the MVC implementation to be used in a portlet environment


Spring IOC
Inversion of control is all about Object Dependencies

Traditional Object Creation Approach
Direct Object Creation new Employee()
FactoryImplementation EmpFactory().getEmp()
JNDI Services naming.lookup()

Spring Approach

Spring Container creates all the objects,
wires them together by setting the necessary
properties, and determines when methods will
be invoked.


Spring Container
Fundamental part of the framework.
Two packages provides the basis for the Spring Framework's IoC container.
– org.springframework.beans
– org.springframework.context

BeanFactory provides the configuration framework and basic functionality,
and the ApplicationContext adds more enterprise-specific functionality.

The org.springframework.beans.factory.BeanFactory is the actual representati
the Spring IoC container

Responsible for containing and managing beans.

The most commonly used BeanFactory implementation is the XmlBeanFactor

The XmlBeanFactory takes XML configuration metadata and uses it to create
configured system or application.


Spring Container

The interface org.springframework.context.ApplicationContext represents the
Spring IoC container and is responsible for instantiating, configuring, and
assembling the beans.

The container gets its instructions by reading configuration metadata.

The configuration metadata is represented in XML and Java annotations

Several implementations of the ApplicationContext interface are supplied
with Spring.

In standalone applications it is common to create an instance of
ClassPathXmlApplicationContext or FileSystemXmlApplicationContext


Ways To Initialize Spring Container


Type of Dependency Injection

Setter method Injection

Constructor Injection

Configuration File Injection


Examples for dependency Injection
Setup Enviornment for Spring

Install JAVA
If you are running Windows and installed the JDK in C:jdk1.6.0_15, you would have to
put the following line in your C:autoexec.bat file.
set PATH=C:jdk1.6.0_15bin;%PATH%
set JAVA_HOME=C:jdk1.6.0_15

Unix (Solaris, Linux, etc.), if the SDK is installed in /usr/local/jdk1.6.0_15 and you use the
C shell, you would put the following into your .cshrc file.
setenv PATH /usr/local/jdk1.6.0_15/bin:$PATH
setenv JAVA_HOME /usr/local/jdk1.6.0_15

Download Spring Jars

Install Common Logging
Download Apache Commons Logging API from http://commons.apache.org/logging

Install Eclipse and setup for Spring


Reference to Other Beans (DI)


Some More Example
Alias

Import

Initialize bean static Bean Factory Method
<bean id="mp3ply" class="com.test.Mp3Player" factory-method="factoryMethod">

</bean>

public Class Mp3Player{
private static Mp3Player mp3ply = new Mp3Player();
public Mp3Player(){}

public static Mp3Player factoryMethod(){
return mp3ply;
}
}


Some More Example

Collections

Inner Beans

Autowire

Namespaces

Depends Upon

ApplicationContextAware interface

BeanNameAware interface

InitializingBean interface


Beans Scopes

Scope Description

This scopes the bean definition to a single instance per
singleton
Spring IoC container (default).

This scopes a single bean definition to have any number of
prototype
object instances.
This scopes a bean definition to an HTTP request. Only
request valid in the context of a web-aware Spring
ApplicationContext.
This scopes a bean definition to an HTTP session. Only
session valid in the context of a web-aware Spring
ApplicationContext.
This scopes a bean definition to a global HTTP session.
global-session Only valid in the context of a web-aware Spring
ApplicationContext.


Beans Life Cycle
 When a bean is instantiated, it may be required to perform some initializatio
to get it into a usable state

When the bean is no longer required and is removed from the container,
some cleanup may be required.

Register the shutdown hook for the ApplicationContext

Callback Methods: Init and destroy methods
The init-method attribute specifies a method that is to be called
on the bean immediately upon instantiation
destroy-method specifies a method that is called just before a bean
is removed from the container.


Beans Post Processors
 The BeanPostProcessor interface defines callback methods that you can
implement to provide your own instantiation logic

You can also implement some custom logic after the Spring container finishe
instantiating, configuring, and initializing a bean by impl PostProcessors

You can have multiple Bean Post processor and can define their order of
execution

ApplicationContext automatically detects any bean as a post processor who
implements BeanPostProcessor Interface


Aspect Oriented Programming(AOP)

ObjectA ObjectC
methodA()
methodA()
.
.
.
.
methodN()
methodN()v
Logging Security

Aspect Configuration
ObjectB ObjectD
methodA() methodA()
. .
. .
methodN() methodN()


Complements OO programming

Aspect Oriented Programming entails breaking down program logic into dist
parts called so-called concerns

Cross-cutting concerns are conceptually separate from the application's
business logic, e.g. ogging, auditing, declarative transactions, security, and
caching etc

Spring AOP module provides interceptors to intercept an application,
for example, when a method is executed, you can add extra functionality
before or after the method execution.


Components of AOP
Aspect – unit of modularity for crosscutting concerns

Join point – well-defined points in the program flow

Pointcut – join point queries where advice executes

Advice – the block of code that runs based on the pointcut definition

Weaving – can be done at runtime or compile time.
Inserts the advice (crosscutting concerns) into the code (core concerns).


Setting up AOP Environment in Eclipse
AOP Dependencies
AspectJ: http://www.eclipse.org/aspectj/downloads.php
AOP Alliance: http://aopalliance.sourceforge.net/
CGILIB: http://cglib.sourceforge.net/
Spring 3 ASM: http://asm.ow2.org/

Examples…..


Spring DAO and ORM
 Built in code templates that support JDBC, Hibernate, JDO,
and iBatis SQL Maps

Simplifies data access coding by reducing redundant code and
helps avoid common errors.

 Alleviates opening and closing connections in your DAO code.

No more ThreadLocal or passing Connection/Session objects.

Transaction management is handled by a wired bean

You are dropped into the template with the resources you need
for data access – Session, PreparedStatement, etc.

Optional separate JDBC framework


JdbcTemplate
Central class in the JDBC core package

Handles the creation and release of resources.

Executes the core JDBC workflow like statement creation
and
Execution

 Executes
– SQL queries
– update statements
– stored procedure calls
– iteration over ResultSets
– extraction of returned parameter values.

Also catches JDBC exceptions


DataSource Configuration


Spring ORM : Working with Hibernate


Q&A


Thanks

if you have any query concerns
write to me
on
rajkrrsingh@gmail.com


Spring framework

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