Hi friend,


The Spring Framework provides solutions to many technical challenges faced by Java developers and organizations wanting to create applications based on the Java platform. Because of the size and complexity of the functionality offered, it can be hard to distinguish the major building blocks from which the framework is composed. The Spring Framework is not exclusively linked to the Java Enterprise platform, although its far-reaching integration in this area is an important reason for its popularity.


With inversion of control , instead of executing application code at startup, a library called a framework is called. The framework then invokes the application code. The goal of inversion of control is to create a separation between the code itself and how the various pieces of code are connected together. It makes code much more readable.

There are two types of inversion of control: dependency injection and dependency lookup. In both cases, the framework instantiates the applications? objects. In the case of dependency injection, the framework knows how the dependencies of the objects are to be set. In the case of dependency lookup, the framework will ask the objects itself how their dependencies are to be set.

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Spring reads the dependencies from an xml file, usually called applicationContext.xml, that (appart from the formatting which I can?t get right) looks as follows:


<bean id="frontend" class="com.soccer.frontend.FrontendImpl">
<property name="matchService" ref="matchService"/>
<property name="clubService" ref="clubService"/>
</bean>

<bean id="matchService" class="com.soccer.service.MatchServiceImpl">
<property name="matchDao" ref="matchDao"/>
</bean>

<bean id="clubService" class="com.soccer.service.clubServiceImpl">
< property name="clubDao" ref="clubDao"/>
</bean>

<bean id="matchDao" class="com.soccer.data.dao.matchDaoImpl">
< property name="database" ref="database"/>
</bean>

<bean id="clubDao" class="com.soccer.data.dao.clubDaoImpl">
< property name="database" ref="database"/>
</bean>

<bean id="database" class="com.soccer.data.database.DatabaseImpl">
< property name="username" value="user"/>
< property name="password" value="secret"/>
< property name="url" value="jdbc:mysql://localhost:3306/soccer_db"/>;
</bean>

Aspect-Oriented Programming(AOP) complements Object-Oriented Programming (OOP) by providing another way of thinking about program structure. In addition to classes, AOP gives you aspects. Aspects enable modularization of concerns such as transaction management that cut across multiple types and objects. (Such concerns are often termed crosscutting concerns.)

One of the key components of Spring is the AOP framework. While the Spring IoC container does not depend on AOP, meaning you don't need to use AOP if you don't want to, AOP complements Spring IoC to provide a very capable middleware solution.



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http://www.roseindia.net/spring/

Thanks.