Spring Boot

✓ Spring Boot

Spring Boot is a Spring module that provides the RAD (Rapid Application Development) feature to the Spring framework. Spring Boot provides an easier and faster way to set up, configure, and run both Java Based and Web Based Applications. Spring Boot is an opinionated, easy to get-started addition to the Spring platform – highly useful for creating stand-alone, production-grade applications with minimum effort.

✓ Difference Between Spring and Spring Boot

Spring	Spring Boot
Spring Framework is a widely used Java EE framework for building applications.	Spring Boot Framework is widely used to develop REST APIs.
Spring aims to simplify Java EE development that makes developers more productive.	Spring Boot aims to shorten the code length and provide the easiest way to develop Web Applications.
The primary feature of the Spring Framework is dependency injection.	The primary feature of Spring Boot is Autoconfiguration. Spring Boot automatically configures the classes based on the requirement.
Spring helps to make things simpler by allowing us to develop loosely coupled applications.	Spring Boot helps to create a stand-alone application with less configuration.
The developer writes a lot of code (boilerplate code) to do the minimal task.	Spring Boot reduces boilerplate code.
To test the Spring project, we need to set up the sever explicitly.	Spring Boot offers embedded server such as Jetty and Tomcat, etc.
Spring does not provide support for an in-memory database.	Spring Boot offers several plugins for working with an embedded and in-memory database such as H2.
Developers manually define dependencies for the Spring project in pom.xml.	Spring Boot comes with the concept of starter in pom.xml file that internally takes care of downloading the dependencies JARs based on Spring Boot Requirement.

✓ Difference Between Spring MVC and Spring Boot

Spring MVC	Spring Boot
Spring MVC is a model view controller-based web framework under the Spring framework.	Spring Boot is a module of Spring for packaging the Spring-based application with sensible defaults.
Spring MVC provides ready to use features for building a web application.	Spring Boot provides default configurations to build Spring-powered framework.
Spring MVC requires build configuration manually.	There is no need to build configuration manually.
A Deployment descriptor is required.	There is no requirement for a deployment descriptor.
Spring MVC specifies each dependency separately.	Spring Boot avoids boilerplate code and wraps dependencies together in a single unit.
Spring MVC takes more time to achieve the same.	Spring Boot reduces development time and increases productivity.

✓ Spring Boot Annotation

Annotation	Description
SpringBootApplication	We can mark the main class of a Spring Boot application.
EnableAutoConfiguration	Spring Boot looks for auto-configuration beans on its classpath and automatically applies.
ConditionalOnProperty	We can make conditions on the values of properties.
ConditionalOnBean	We want to define conditions based on the presence or absence of a specific bean.
ConditionalOnMissingBean	We want to define conditions based on the presence or absence of a specific bean.
ConditionalOnResource	We can make Spring to use a definition only when a specific resource is present.
ConditionalExpression	Spring will use the marked definition when the SpEL expression is evaluated to true.
ConditionalOnWebApplication	We can create conditions based on if the current application is a web application
ConditionalOnNotWebApplication	We can create conditions based on if the current application isn't a web application
Conditional	We can create a class evaluating the custom condition. We tell Spring to use this custom condition with @Conditional
ConditionalOnClass	Spring will only use the marked auto-configuration bean if the class in the annotation's argument is present/absent
ConditionalOnMissingClass	Spring will only use the marked auto-configuration bean if the class in the annotation's argument is present/absent
GetMapping	GetMapping Annotation is used for mapping HTTP GET requests onto specific handler methods. @GetMapping is a composed Annotation that acts as a shortcut for @RequestMapping(method = RequestMethod.GET)
PostMapping	PostMapping Annotation is used for mapping HTTP POST requests onto specific handler methods. @PostMapping is a composed annotation that acts as a shortcut for @RequestMapping(method = RequestMethod.POST)
PutMapping	PutMapping Annotation is used for mapping HTTP PUT requests onto specific handler methods. @PutMapping is a composed annotation that acts as a shortcut for @RequestMapping(method = RequestMethod.PUT)
PatchMapping	PatchMapping Annotation is used for mapping HTTP PUT requests onto specific handler methods. @PutMapping is a composed annotation that acts as a shortcut for @RequestMapping(method = RequestMethod.PUT)
DeleteMapping	DeleteMapping Annotation is used for mapping HTTP PATCH requests onto specific handler methods. @PatchMapping is a composed annotation that acts as a shortcut for @RequestMapping(method = RequestMethod.PATCH)

✓ Spring Boot Starters

Spring Boot provides a number of starters that allow us to add jars in the classpath. Spring Boot built-in starters make development easier and rapid. Spring Boot Starters are the dependency descriptors.

Starters Name	Description
spring-boot-starter-thymeleaf	It is used to build MVC web applications using Thymeleaf views.
spring-boot-starter-data-couchbase	It is used for the Couchbase document-oriented database and Spring Data Couchbase.
spring-boot-starter-artemis	It is used for JMS messaging using Apache Artemis.
spring-boot-starter-web-services	It is used for Spring Web Services.
spring-boot-starter-mail	It is used to support Java Mail and Spring Framework's email sending.
spring-boot-starter-data-redis	It is used for Redis key-value data store with Spring Data Redis and the Jedis client.
spring-boot-starter-web	It is used for building the web application, including RESTful applications using Spring MVC. It uses Tomcat as the default embedded container.
spring-boot-starter-data-gemfire	It is used to GemFire distributed data store and Spring Data GemFire.
spring-boot-starter-activemq	It is used in JMS messaging using Apache ActiveMQ.
spring-boot-starter-data-elasticsearch	It is used in Elasticsearch search and analytics engine and Spring Data Elasticsearch.
spring-boot-starter-integration	It is used for Spring Integration.
spring-boot-starter-test	It is used to test Spring Boot applications with libraries, including JUnit, Hamcrest, and Mockito.
spring-boot-starter-jdbc	It is used for JDBC with the Tomcat JDBC connection pool.
spring-boot-starter-mobile	It is used for building web applications using Spring Mobile.
spring-boot-starter-validation	It is used for Java Bean Validation with Hibernate Validator.
spring-boot-starter-hateoas	It is used to build a hypermedia-based RESTful web application with Spring MVC and Spring HATEOAS.
spring-boot-starter-jersey	It is used to build RESTful web applications using JAX-RS and Jersey. An alternative to spring-boot-starter-web.
spring-boot-starter-data-neo4j	It is used for the Neo4j graph database and Spring Data Neo4j.
spring-boot-starter-data-ldap	It is used for Spring Data LDAP.
spring-boot-starter-websocket	It is used for building the WebSocket applications. It uses Spring Framework's WebSocket support.
spring-boot-starter-aop	It is used for aspect-oriented programming with Spring AOP and AspectJ.
spring-boot-starter-amqp	It is used for Spring AMQP and Rabbit MQ.
spring-boot-starter-data-cassandra	It is used for Cassandra distributed database and Spring Data Cassandra.
spring-boot-starter-social-facebook	It is used for Spring Social Facebook.
spring-boot-starter-jta-atomikos	It is used for JTA transactions using Atomikos.
spring-boot-starter-security	It is used for Spring Security.
spring-boot-starter-mustache	It is used for building MVC web applications using Mustache views.
spring-boot-starter-data-jpa	It is used for Spring Data JPA with Hibernate.
spring-boot-starter	It is used for core starter, including auto-configuration support, logging, and YAML.
spring-boot-starter-groovy-templates	It is used for building MVC web applications using Groovy Template views.
spring-boot-starter-freemarker	It is used for building MVC web applications using FreeMarker views.
spring-boot-starter-batch	It is used for Spring Batch.
spring-boot-starter-social-linkedin	It is used for Spring Social LinkedIn.
spring-boot-starter-cache	It is used for Spring Framework's caching support.
spring-boot-starter-data-solr	It is used for the Apache Solr search platform with Spring Data Solr.
spring-boot-starter-data-mongodb	It is used for MongoDB document-oriented database and Spring Data MongoDB.
spring-boot-starter-jooq	It is used for jOOQ to access SQL databases. An alternative to spring-boot-starter-data-jpa or spring-boot-starter-jdbc.
spring-boot-starter-jta-narayana	It is used for Spring Boot Narayana JTA Starter.
spring-boot-starter-logging	It is used for logging using Logback. Default logging starter.
spring-boot-starter-jta-bitronix	It is used for JTA transactions using Bitronix.
spring-boot-starter-social-twitter	It is used for Spring Social Twitter.
spring-boot-starter-data-rest	It is used for exposing Spring Data repositories over REST using Spring Data REST.
spring-boot-starter-actuator	It is used for Spring Boot's Actuator that provides production-ready features to help you monitor and manage your application.
spring-boot-starter-cloud-connectors	It is used for Spring Cloud Connectors that simplifies connecting to services in cloud platforms like Cloud Foundry and Heroku.
spring-boot-starter-remote-shell	It is used for the CRaSH remote shell to monitor and manage your application over SSH. Deprecated since 1.5.
spring-boot-starter-undertow	It is used for Undertow as the embedded servlet container. An alternative to spring-boot-starter-tomcat.
spring-boot-starter-jetty	It is used for Jetty as the embedded servlet container. An alternative to spring-boot-starter-tomcat.
spring-boot-starter-tomcat	It is used for Tomcat as the embedded servlet container. Default servlet container starter used by spring-boot-starter-web.
spring-boot-starter-log4j2	It is used for Log4j2 for logging. An alternative to spring-boot-starter-logging.

✓ Creating a Spring Boot Project

Step 1 :	Open the Spring Initializr web site : https://start.spring.io
Step 2 :	Provide the Group Name. We have provided Group Name com.jst
Step 3 :	Provide the Artifact Name. We have provided Artifact Name spring-boot-addition.
Step 4 :	Next, Click on the Generate Button.
Step 5 :	Open Download Folder then Extract spring-boot-addition.rar zip file.
Step 6 :	Open any IDE like Eclipse, STS, IntelliJ, NetBeans etc..
Step 7 :	Click File -> Import -> Maven Existing Project -> Next -> Browse -> Select the Project -> Finish .

✓ Run Spring Boot App using Command Line C:\Java\addition-app\target> java -jar addition-app-0.0.1-SNAPSHOT.jar
C:\Java\addition-app\target> java -jar addition-app-0.0.1-SNAPSHOT.jar --server.port=9080
C:\Java\addition-app\target> java -jar addition-app-0.0.1-SNAPSHOT.jar --server.port=9080 --spring.profile.active=dev
C:\Java\addition-app\target> java -jar -Dspring.config.location = C:\Java\addition-app\src/main/resources\application.properties addition-app-0.0.1-SNAPSHOT.jar
C:\Java\addition-app\target> java -jar -Dspring.config.location = C:\Java\addition-app\src\main\resources\application.properties addition-app-0.0.1-SNAPSHOT.jar