Friday, July 7, 2017

Introduction to Spring Boot

Spring Boot is another module provided by Spring Framework which provides RAD (Rapid Application Development) feature to Spring framework. Using boot, we can create standalone Spring based application that you can “just run” in no time and Most Spring Boot applications need very little Spring configuration and it does not require any XML configuration. It uses convention over configuration software design paradigm that means it decrease the effort of developer.

Why Spring Boot?

As we know Spring framework provides flexibility to configure the beans in multiple ways such as XML, Annotations and JavaConfig. With the number of features increased the complexity also gets increased and configuring Spring applications becomes tedious and error-prone.
Spring Boot:
·         Ease the dependency Management, Java-based applications Development, Unit Test and Integration Test Process.
    • Eg: By adding springboot-starter-web dependency to pom.xml file will pull by default all the commonly used libraries such as spring-webmvc, jackson-json, validation-api and tomcat into your Spring MVC applications.
  • Do the Auto Configuration
    • Eg: By Adding above dependency will adds all these libraries but also configures the commonly registered beans like DispatcherServlet, ResourceHandlers, MessageSource etc beans with sensible defaults. Will see JDBC configuration blog in next blog.
  • Support for Embedded Servlet (Tomcat, Jetty )
    • It provides Embedded HTTP servers like Tomcat, Jetty etc. to develop and test our web applications very easily.
  • Easy to develop Spring Based applications with Java or Groovy and it reduces lots of development time and increases productivity. It also avoids writing lots of boilerplate Code, Annotations and XML Configuration.
  • Easy to integrate Spring Boot Application with its Spring Ecosystem like Spring-jdbc, Spring-orm, Spring-data-jpa, Spring security etc.

Spring Boot Components

·         Spring Boot Starter

    • Spring boot starter are just JAR Files or set of convenient dependency descriptors which we can include in our application to makes development easier and faster. It follows a naming pattern like: spring-boot-starter-*, where * is a particular type of application. This naming structure is intended to help when you need to find a starter. For example, if we want to get started using Spring and JPA for database access, just include the spring-boot-starter-data-jpa dependency in your project.

·        Spring Boot AutoConfigurator

·   It used by Spring Boot Framework to provide “Auto-Configuration. It attempts to automatically configure your Spring application based on the jar dependencies that you have added. For example, If HSQLDB is on your classpath, and you have not manually configured any database connection beans, then we will auto-configure an in-memory database.
·      You need to opt-in to auto-configuration by adding the @EnableAutoConfiguration or @SpringBootApplication annotations to one of your @Configurationclasses.

·        Spring Boot Actuator

·         It is used to expose different types of information about the running application – health, metrics, info, dump, env etc.
·         We can choose to manage and monitor our application using HTTP endpoints, with JMX or even by remote shell (SSH or Telnet). Auditing, health and metrics gathering can be automatically applied to your application.
·         To start using the existing actuators in Boot – we’ll just need to add the spring-boot-actuator dependency to the pom:
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-actuator</artifactId>
    <version>1.4.2.RELEASE</version>
</dependency>

·        Spring Boot CLI

·         Tool to run and test Spring Boot applications from command prompt. When we run Spring Boot applications using CLI, then it internally uses Spring Boot Starter and Spring Boot AutoConfigurate components to resolve all dependencies and execute the application.
·         It internally contains Groovy and Grape (JAR Dependency Manager) to add Spring Boot Defaults and resolve all dependencies automatically.

·        Spring Boot Initilizr

·         It is a web tool which is provided by Spring on official site using which Spring Boot project can be created by providing project details. Check here in depth details.


That’s it all about Spring Boot Framework. Will add few more blogs for depth details.