Spring Framework
The core features of the Spring Framework
can be used by any Java application, but there are extensions for building web
applications on top of the Java EE platform. Although the Spring Framework does not
impose any specific programming model, it has become popular in the
Java community as an alternative to, replacement for, or even addition to the Enterprise JavaBean (EJB) model.
The Spring Framework comprises several modules that
provide a range of services:
DAO & JDBC
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ORM
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JEE
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WEB MVC Module
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AOP
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IOC
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IOC
(Inversion Of Control:
For all modules IOC (Inversion Of Control)
is the base Module.
IOC will take care of creating an object to
the class and setting values of the attributes of the object.
IOC container mainly used for
configuration. Data is supplied to the framework through xml file. Whatever we
set inside xml file, will be used inside java program.
The IOC module provides configuration to
the other modules of spring framework.
AOP(Aspect
Oriented Programming):
It is anti Object oriented programming. Oop
concepts mainly used for hierarchical (inherited) classes, the classes which
are under one hierarchy. AOP is for any classes, horizontally no relation is
required among the classes. After developing we the aspect we can apply that
aspect horizontally to any of the classes. No relation is required among the
classes.
JDBC
DAO (Java Enterprise Edition and Data Access Object) module:
Used for interacting with the database
using JDBC API. In order to minimize development work while interacting with
the database by using JDBC, we use DAO module. DAO module internally uses pure
JDBC API.
No additional features like ORM or cache
Mechanisms are used. It receives just the SQL query and does all the necessary
steps to send the query to the database.
ORM
(Object Relational Mapping):
If we are using
hibernate framework to interact with the database from a java program, then the
interaction procedure is simplified by using Spring ORM. The ORM tools
popularly used today are hibernate and iBatis. The ORM tools usage is
simplified by the ORM module.
ORM module
straightaway gives Session object by starting the Transaction to the java
program.
WEB
MVC (Model View Controller) module:
Almost similar to
struts and JSF. Used only for developing web applications.
JEE:
Simplifying development of EJB, JMS (Java
Messaging Service).
IOC Module
In eclipse go to FileàNew àProjectàJava project: app1
First let’s see one simple program without
using Spring framework.
app1/src/com/lara/Person.java
packagecom.lara;
publicclass
Person {
private
String firstName, lastName;
public
Person()
{
System.out.println("Person");
}
public
String getFirstName() {
System.out.println("getFirstName");
returnfirstName;
}
publicvoidsetFirstName(String
firstName) {
System.out.println("setFirstName");
this.firstName =
firstName;
}
public
String getLastName() {
System.out.println("getLastName");
returnlastName;
}
publicvoidsetLastName(String
lastName) {
System.out.println("setLastName");
this.lastName =
lastName;
}
}
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Manager.java
packagecom.lara;
publicclass
Manager {
publicstaticvoid
main(String[] args) {
Person p1 = new
Person();
p1.setFirstName("Ramu");
p1.setLastName("B");
System.out.println("object
is ready withteh state");
System.out.println(p1.getFirstName());
System.out.println(p1.getLastName());
}
}
Output:
Person
setFirstName
setLastName
object is
ready withteh state
getFirstName
Ramu
getLastName
B
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Without framework
we are managing one object to bean class
Create a xml file
to store the configuration data.
Right click on srcàNewàFile: create on .xml file, Eg. beans.xml (can be any name).
beans.xml
<?xmlversion="1.0"encoding="UTF-8"?>
<!--
- DispatcherServlet application context for
the image database.
-->
<beansxmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-2.5.xsd">
<beanid="person1"class="com.lara.Person">
<propertyname="firstName"value="Sagar"/>
<propertyname="lastName"value="B"/>
</bean>
</beans>
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Manager2.java
packagecom.lara;
importorg.springframework.beans.factory.BeanFactory;
importorg.springframework.beans.factory.xml.XmlBeanFactory;
importorg.springframework.core.io.ClassPathResource;
publicclass
Manager2 {
publicstaticvoid
main(String[] args) {
BeanFactory factory = newXmlBeanFactory(newClassPathResource("beans.xml"));
Person p1 = (Person)
factory.getBean("person1");
System.out.println("Object
is ready with the state");
System.out.println(p1.getFirstName());
System.out.println(p1.getLastName());
}
}
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