Spring Boot

Spring Boot!!!!! WHAT & WHY?

Spring boot helps developer to concentrate more on Business logic than configurations.

Spring boot is best assistant to developer reducing efforts to develop application without required to write same boilerplate configuration again and again.

If you have developed application in traditional way you would understand the pain of building project adding dependencies.

How it Assists or Why its Popular ?

Lets discuss some of the features or why to use Spring Boot.

1. Managing the dependencies made easy.

As I said above in old applications if you need to add jars it was not so easy task because other dependent jars would trouble you.

This was simplified here by just adding starters

Something it looks like this

Spring-boot-starter-*

Where * can be any dependencies like

  Spring-boot-starter-web  ->This commonly used for Spring MVC.

  Spring-boot-starter-jpa  -> This pulls jpa + hibernate .

  So on…

It looks like this :

Pom.xml

<parent>

              <groupId>org.springframework.boot</groupId>

              <artifactId>spring-boot-starter-parent</artifactId>

       </parent>

2.Almost made zero configuration.

Spring-boot-starter-* will not only add dependencies but also configures commonly registered bean like Dispatcher Servlet, Resource handler, Message source etc.

This was mainly introduced to achieve Boiler plate config by automatic configuration of registering beans.

Registering beans based on

• ·         Class should be available in particular path
• ·         Presence or absence of bean.
• ·         Presence of System properties.
• ·         Absence of configuration file.

3.Spring boot has Embedded Servlet container.

No need to do any extra configuration for servlet container like traditional way just add -web in starter then spring-boot-starter-tomcat automatically pulled it has embedded container.

4.Actuator

Key features provides several web end points.

By Actuator you can find out how beans are wired through spring application context

Spring-boot-starter-actuator to be added in pom.xml

Some of them listed below

/health               : This is get method which displays health of application

/env                   : This is get method which displays health of environment properties.

/shutdown         : This is post method which shutdowns the application.

FAQs:

1.For Datasource, EMF transaction manager beans automatically created HOW???

Ans: If we have in memory D.B driver like H2 or HSQL automatically creates in memory data source and do automatically with sensible defaults

2 How connection established for Mysql ?

Ans: App.properties files will have connection. Boot creates Data Source with this properties.

3.How it has Embedded Servlet Container?

Ans: Spring-boot-starter-web 

When web is added  then spring-boot-starter-tomcat is automatically pulled. It has embedded container.

4.How to change to jetty server instead of tomcat?

Ans: Exclude Spring-boot-starter-tomcat and include Spring-boot-starter-jetty

5.What is Fat jar

Ans: Spring-boot-maven plugin creates single deployment unit which runs in production without IDE that’s nothing but fat jar.

Thanks for Reading!!!Comments and Suggestions always welcome