This spring tutorial provides in-depth concepts of Spring Framework with simplified examples.
It was developed by Rod Johnson in 2003. Spring framework makes the easy development of JavaEE application.
It is helpful for beginners and experienced persons.
Spring is a lightweight framework. It can be thought of as a framework of frameworks because it provides support to various frameworks such as Struts, Hibernate, Tapestry, EJB, JSF etc.
The framework, in broader sense, can be defined as a structure where we find solution of the various technical problems.
The Spring framework comprises several modules such as IOC, AOP, DAO, Context, ORM, WEB MVC etc. We will learn these modules in next page. Let's understand the IOC and Dependency Injection first.
Inversion Of Control (IOC) and Dependency Injection
These are the design patterns that are used to remove dependency from the programming code. They make the code easier to test and maintain.
Let's understand this with the following code:
In such case, there is dependency between the Employee and Address (tight coupling). In the Inversion of Control scenario, we do this something like this:
Thus, IOC makes the code loosely coupled. In such case, there is no need to modify the code if our logic is moved to new environment.
In Spring framework, IOC container is responsible to inject the dependency. We provide metadata to the IOC container either by XML file or annotation.
Advantage of Dependency Injection
- makes the code loosely coupled so easy to maintain
- makes the code easy to test
Advantages of Spring Framework
There are many advantages of Spring Framework. They are as follows:
1) Predefined Templates
Spring framework provides templates for JDBC, Hibernate, JPA etc. technologies. So there is no need to write too much code. It hides the basic steps of these technologies.
Let's take the example of JdbcTemplate, you don't need to write the code for exception handling, creating connection, creating statement, committing transaction, closing connection etc. You need to write the code of executing query only. Thus, it save a lot of JDBC code.
2) Loose Coupling
The Spring applications are loosely coupled because of dependency injection.
3) Easy to test
The Dependency Injection makes easier to test the application. The EJB or Struts application require server to run the application but Spring framework doesn't require server.
Spring framework is lightweight because of its POJO implementation. The Spring Framework doesn't force the programmer to inherit any class or implement any interface. That is why it is said non-invasive.
5) Fast Development
The Dependency Injection feature of Spring Framework and it support to various frameworks makes the easy development of JavaEE application.
6) Powerful abstraction
It provides powerful abstraction to JavaEE specifications such as JMS, JDBC, JPA and JTA.
7) Declarative support
It provides declarative support for caching, validation, transactions and formatting.
Topics of Spring Framework
The topics of Spring Framework covered by javatpoint is given below.