Spring Framework Tutorial

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 Framework

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.

4) Lightweight

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.

Prerequisites to Learn Spring Framework

Before learning Spring Framework, you should have a basic understanding of Java programming, Object-Oriented Programming (OOP) concepts, collections, exception handling, JDBC, and relational databases. Familiarity with web technologies such as HTML, CSS, HTTP, Servlets, and JSP will also help you understand Spring-based web applications more effectively.

Audience to Learn Spring Framework

This Spring Framework tutorial is designed for students, beginners, Java developers, software engineers, and professionals who want to develop enterprise-level Java applications. It is also suitable for anyone interested in learning dependency injection, inversion of control (IoC), web development, microservices, and modern Java application development.

Career Opportunities After Learning Spring Framework

After learning Spring Framework, you can pursue roles such as Java Developer, Spring Developer, Spring Boot Developer, Backend Developer, Full Stack Developer, Software Engineer, Enterprise Application Developer, and Microservices Developer. Since Spring is one of the most widely used Java frameworks in the industry, it is a highly valuable skill for building scalable and enterprise-grade applications.

Spring Framework MCQs

1. In Spring, what is the primary purpose of the @Component annotation?

1. To indicate that a class is a repository
2. To define a class as a Spring bean
3. To configure aspect-oriented programming
4. To manage transaction boundaries

2. What is the primary difference between @RequestMapping and @GetMapping annotations in Spring MVC?

1. @RequestMapping is used for HTTP GET requests only, while @GetMapping can handle all HTTP methods.
2. @GetMapping is a specialized version of @RequestMapping for handling HTTP GET requests only.
3. @RequestMapping is used within service layers, while @GetMapping is used in controller layers.
4. @RequestMapping does not support path variables, while @GetMapping does.

3. In Spring Boot, which file is commonly used to configure properties such as database URLs, server ports, and other environment-specific settings?

1. application.properties
2. config.xml
3. settings.yml
4. bootstrap.json

4. Which of the following annotations in Spring is used to handle exceptions at the controller level?

1. @ExceptionHandler
2. @RestController
3. @ControllerAdvice
4. @ResponseStatus

5. In Spring Data JPA, what is the purpose of the @Query annotation?

1. To mark a class as a query service
2. To define a JPQL or SQL query directly on a repository method
3. To configure caching for query results
4. To establish a connection to the database