Spring Framework is a powerful open-source Java application development framework that makes it easy to create robust, high-performance applications.
Open-source refers to something people can access, modify and share freely as the source code is freely available.
An open-source application framework is a template for software development created by a group of software developers. There exist different types of templates used for different purposes, such as creating user interfaces, websites, and basic software applications.
If you’re new to application development, getting started with Spring Framework might be a great start for you. In this article, you’ll learn what it is and how to use it.
What is Spring Framework?
Spring Framework is an open-source framework that developers use to create enterprise Java applications. This framework was created by Rod Johnson and released in 2003 under the Apache 2.0 license.
Some programmers usually bash Java and claim it’s cumbersome to create basic applications. Spring Framework aims to simplify the cumbersome and complex process of developing enterprise Java applications.
Spring is wide. It is thus advisable that you first understand what the Spring framework is before start using other Spring-based projects such as Spring Boot, Spring GraphQL, and Spring Cloud.
Why use Spring Framework?
- Flexible. This framework offers technologies such as Aspect-oriented programming (AOP), Dependency injection (DI), and Plain Old Java Object (POJO). You can thus use Spring to achieve different goals.
- Spring is fast. Despite having all these technologies, Spring Framework is still lightweight, making it ideal to create scalable and robust enterprise web applications.
- Awesome community. Spring has a diverse community, and you can trust it to help with various solutions in your hour of need.
- Secure. Spring is known for its security measures, and vulnerabilities are always fixed through frequent patches. Third party dependencies are always monitored to ensure that their vulnerabilities don’t interfere with the core process.
- Productive. Spring Framework streamlines the experience of developing Java enterprise applications.
Supports aspect-oriented programming
Aspect-oriented programming provides more modularity to crosscutting concerns. AOP also compliments Object-oriented programming.
The main unit of modularity in AOP is a cross-cutting concern (Aspect). Developers can thus create declarative enterprise services and custom aspects.
Inversion of Control (IoC) Container
IoC container offers a streamlined way of managing and configuring Java objects. The lifecycle of a defined Java object is managed by this container, which significantly increases the reconfigurability of a Spring-based application.
Inversion of Control utilizes dependency lookup or dependency injection patterns to offer the object reference runtime. IoC container comes with assembler code needed for configuration management.
Data access framework
The data communication process is simplified as Spring has direct support for Hibernate, JDBC, and Java Persistence API (JPA), some of the most popular data access frameworks in Java. You can also bank on this framework to offer features such as resource wrapping, exception handling, and resource management for all the supported data access frameworks.
Spring MVC Framework
Developers can use this request-based framework to create customized MVC implementations that suit their needs.
The DispatcherServlet class, tasked with handling users’ requests and then forwarding them to the right controller, sits at the core of Spring MVC. The controller can thus process a request, create a model and offer information to the end user through a specified view.
Has several test frameworks
You can test your Spring-based applications as you develop them through Mock objects, the TestContext framework, or the Spring MVC Test.
Spring framework supports Groovy and Kotlin.
The Spring Framework comes with about 20 modules. The good thing with this framework is that it allows you to pick modules that are applicable to your use case. These modules are grouped into Core Container, AOP (Aspect Oriented Programming), Data Access/Integration, Web, Instrumentation, and Test.
#1. Core Container
The Core Container of Spring Framework contains Core, Beans, Context, and Expression Language models. These language models are useful in the following ways;
- The Core module is the fundamental part of the framework. You will find IoC and Dependency Injection features at the Core.
- The Bean module is known for BeanFactory, a sophisticated implementation of the factory pattern.
- The Context module is built on the Core and Bean Modules. This module inherits its features from the Bean module but adds support for internationalization.
- The Expression Language module offers a powerful expression language for manipulating and querying an object graph at runtime.
#2. Data Access/Integration
JDBC, ORM, OXM, JMS, and Transaction modules make up the Data Access/Integration layer. These modules perform the following;
- The JDBC module has a JBDC-abstraction layer that eliminates the need to do tedious JDBC coding as well as parsing of database-vendor-specific error codes.
- The ORM is an integration layer for some of the popular object-relational mapping APIs such as JPA, JDO, Hibernate, and iBatis. ‘
- The OXM module is an abstraction layer supporting Object/XML mapping implementations for XStream, JAXB, JiBX, Castor, and XMLBeans.
- The Transaction module supports declarative and programmatic transaction management for classes implementing special interfaces.
- The Java Messaging Service (JMS) module has features that produce and consume messages.
#3. AOP (Aspect Oriented Programming) and Instrumentation
This module comes with AOP Alliance-compliant aspect-oriented programming implementation, which makes it easy to define things such as method interceptors. On the other hand, the Instrumentation module offers classloader and class instrumentation support to be used in certain application servers.
Web, Web-Servlet, Web-Struts, and Web-Portlet modules make up the Web layer.
- The Web module is responsible for basic web-oriented integration features like multipart file-upload functionality.
- The Web-Servlet module features Spring’s MVC implementation for web applications.
- The Web-Portlet module mirrors the functionality of the Web-Servlet module. The Web-Portlet module offers MVC implementation to be used in a portlet environment.
- The Web-Socket module supports two-way communication between the server and client in web applications.
The Test module is the last part of Spring’s architecture. It is the module that supports the testing of Spring components with TestNG or JUnit.
Install Spring Framework
Check that Java is installed
Before learning how Spring Framework works, we must install Spring on our PC. Spring documentation has extensive resources on how to get started depending on your operating system.
For our case, we shall use Ubuntu 20.04.5, a Linux-based operating system.
Before installing Spring, ensure that you have Java installed using this command
If you have Java installed, you will have an output similar to this screenshot.
If you don’t have it on your PC, there are several approaches to install Java based on your needs.
Install Spring framework
There are several approaches to installing the Spring framework, as highlighted on Spring docs.
For our case, we will use GVM (the Groovy Environment Manager). You can get GVM using GVMtool or install it on the command line.
Once you have GVM, use the following commands to install and check whether the Spring framework is installed
gvm install springboot
You are likely to get an output that looks like this if Spring is installed
Important terms associated with the Spring framework
Dependency Injection is a feature that allows developers to create independent objects outside of class. DI also allows users to provide those objects to a class in different ways.
Inversion of Control (IoC)
IoC is a concept that transfers the control of portions of a program or objects to a framework or container. In traditional programming, our custom code makes calls to a library. On the other hand, IoC allows a framework (Spring in this case) to make calls to our custom code and control the flow of the program.
Aspect-Oriented Programming (AOP)
AOP is a technique for building common and reusable routines that can be applied in the entire application. Such an approach separates repeatable tasks (like input validation, logging, and error handling) from the core application logic.
Spring Framework Learning Resources
#1. Reactive Programming with Spring Framework 5
This Spring course is made up of videos, articles, and downloadable resources. The course teaches functional programming with Java, how to microservices with Spring WebFlux and how to leverage Reactive types in Spring Data MongoDB.
#2. Spring Framework Master Class
Spring Framework Master Class is paid course which teaches the real way that Java projects use Spring Framework. You will learn how to use various tools such as Spring Boot, JUnit & Mockito, Spring JDBC, Spring AOP, and Hibernate.
#3. Spring Framework In Easy Steps
Spring Framework In Easy Steps is an ideal premium course to take if you want to create End to End Java EE Web Applications using Spring Framework. Some of the things you will learn are how to develop web applications using Spring MVC, how to make Ajax Call Using JQuery and Spring MVC, and how to use Spring JDBC to perform database operations, to mention a few.
#4. Spring Framework 5
Spring Framework 5 course is ideal if you want to learn Learn Spring Framework 5, Spring Data MongoDB, Spring Boot 2, Spring MVC, Spring Data JPA, and Hibernate. You can bank on the 57 hours of on-demand videos, 13 articles, and a lot of downloadable materials.
Java remains to be one of the most popular programming languages in the modern world. Even though new languages are being introduced, frameworks such as Spring bring new life to Java and expand its usefulness. We are thus likely to continue having demand for Java engineers as they are needed to maintain legacy code and also create new applications.
Spring ranks high among Java EE frameworks, and we hope you now understand what Spring Framework is, its features, architecture, and working process. When combined with other Spring projects, Spring Framework offers developers various development tools that can be used across different development environments.