Spring overview & architecture

This is first session about high-level overview of Spring 4 framework

1. Spring
in
Practice
Version 4.0
[ Overview | Design | Architecture | DI & IoC ]
By: SAURABH SHARMA | TechShareZone Community
Source: http://javazone.techsharezone.com | [phone]
Session: 1

2. Created by Rod Jhonson
An open source framework
Spring is an light weight Dependency Injection and Aspect
Oriented Container and framework.
- Spring Overview

3. - Spring framework architecture

4. - Deprecated Methods and Packages
- Java 8 Support
- Groovy Bean Definition DSL
- Spring Core Changes
- Spring Web Module Features
Currently Spring 4.2 is the latest version and they have
enhanced event listener, hibernate, jetty and modern Java
component design with spring framework.
- Spring 4.0 Release and Features

5. Dependency Injection
Also known as IoC (Inversion of Control)
Aspect Oriented Programming
Runtime injection-based
Portable Service Abstractions
The rest of spring
ORM, DAO, Web MVC, Web, etc.
Allows access to these without knowing how they actually
work
- What does Spring offer?

6. Dependency Injection (DI) is a design pattern that removes the dependency
from the programming code so that it can be easy to manage and test the
application.
Constructor-based dependency injection
Constructor-based DI is accomplished when the container invokes a class constructor
with a number of arguments, each representing a dependency on other class.
Setter-based dependency injection
Setter-based DI is accomplished by the container calling setter methods on your
beans after invoking a no-argument constructor or no-argument static factory
method to instantiate your bean.
- Dependency Injection in Spring

7. - IoC is all about Object dependencies.
- Traditional "Pull" approach:
- Direct instantiation
- Looking up a service via JNDI
"Push" approach:
- Something outside of the Object "pushes" its
dependencies into it.
The Object has no knowledge of how it gets its dependencies, it
just assumes they are there.
- The "Push" approach is called "Dependency Injection".
- What is Inversion of Control (IoC)?

8. Typical java bean with a unique id
Beans are normally created by Spring as late as possible
- What is a bean?
Scope Description
Singleton Single instance spring IoC
Prototype Single bean definition to have any number of object instance
Request A bean definition to an HTTP request. Only valid in the context of a web
aware spring applicationContext.
Session A bean definition to an HTTP session. Only valid in the context of a web
aware spring applicationContext.
Global-sessionA bean definition to an global HTTP session. Only valid in the context of a
web aware spring applicationContext.

9. Defines a bean for Spring to manage
Key attributes
class (required): fully qualified java class name
id: the unique identifier for this bean
configuration: (singleton, init-method, etc.)
constructor-arg: arguments to pass to the constructor at creation
time
property: arguments to pass to the bean setters at creation time
Collaborators: other beans needed in this bean (a.k.a
dependencies), specified in property or constructor-arg
Typically defined in an XML file
- What is a bean definition?

10. <?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-4.0.xsd">
<bean id="expense" class="com.tsz.springfactory.model.Expense" scope="singleton“
init-method=“init” destroy-method=“destroy”>
</bean>
</beans>
- Sample bean definition

11. Thank You
“This recepie may not be tasty but it was full of
ingredients of knowledge”