Spring boot
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The document provides an overview of Spring Boot, explaining its purpose as a simplified framework for creating Spring applications, emphasizing features like no code generation, standalone applications, and automatic configuration. It also covers rapid prototyping using Spring CLI, managing dependencies with Gradle, and the integration of Spring Data libraries for database interactions. Additionally, it discusses various packaging options and best practices for developing applications with Spring Boot.
![What
Just
happened?
//
import
org.springframework.web.bind.annotation.Controller
//
other
imports
...
//
@Grab("org.springframework.boot:spring-‐boot-‐web-‐starter:0.5.0")
//
@EnableAutoConfiguration
@Controller
class
Example
{
@RequestMapping("/")
@ResponseBody
public
String
hello()
{
return
"Hello
World!";
}
//
public
static
void
main(String[]
args)
{
//
SpringApplication.run(Example.class,
args);
//
}
}](https://image.slidesharecdn.com/nitocwzq42o0cdcaz3pr-signature-319cfcc8620e7d9e0f5388051cfd90b5f4296773f7c184b947f7eebd1a52d787-poli-141128125009-conversion-gate02/85/Spring-boot-7-320.jpg)
![GSP
continued...
• Sample
request
handler
22
@RequestMapping("/show/{id}")
public
ModelAndView
show(@PathVariable
Long
id)
{
Person
person
=
Person.read(id)
if
(person)
{
//render(view:"/person/show",
model:[personInstance:personInstance])
new
ModelAndView("/person/show",
[personInstance:
Person.get(id)])
}
else
{
log.info
"No
entity
fount
for
id
:
"
+
id
//redirect(controller:"person",
action:"list")
new
ModelAndView("redirect:/person/list")
}
}](https://image.slidesharecdn.com/nitocwzq42o0cdcaz3pr-signature-319cfcc8620e7d9e0f5388051cfd90b5f4296773f7c184b947f7eebd1a52d787-poli-141128125009-conversion-gate02/85/Spring-boot-22-320.jpg)
![Grails
Taglib
23
@grails.gsp.TagLib
@org.springframework.stereotype.Component
class
ApplicationTagLib
{
static
namespace
=
"app"
def
paginate
=
{
attrs
-‐>
String
action
=
attrs.action
Integer
total
=
attrs.total
Integer
currentPage
=
attrs.currentPage
?:
1
Integer
pages
=
(total
/
10)
+
1
out
<<
render(template:
"/shared/pagination",
model:
[action:
action,
total:
total,
currentPage:
currentPage,
pages:
pages]
)
}
}
<app:paginate
total="${personInstanceCount
?:
0}"
currentPage="${currentPage}"
action="/person/list"/>](https://image.slidesharecdn.com/nitocwzq42o0cdcaz3pr-signature-319cfcc8620e7d9e0f5388051cfd90b5f4296773f7c184b947f7eebd1a52d787-poli-141128125009-conversion-gate02/85/Spring-boot-23-320.jpg)
Spring boot
- 1. Spring Boot By Bhagwat Kumar
- 2. Agenda • What and Why? • Key features of Spring boot • Prototyping using CLI. • Gradle primer • Managing profiles aka environment in grails • Using Spring data libraries e.g. MongoDB • Using GORM • Presentation layer • Using GSP 2
- 3. What and why? • Its not a replacement for Spring framework but it presents a small surface area for users to approach and extract value from the rest of Spring. • Spring-‐boot provides a quick way to create a Spring based application from dependency management to convention over configuration. • Grails 3.0 will be based on Spring Boot. image source : http://spring.io/blog/2013/08/06/spring-‐boot-‐simplifying-‐spring-‐for-‐everyone 3
- 4. Key Features • Stand-‐alone Spring applications • No code generation/ No XML Config • Automatic configuration by creating sensible defaults • Starter dependencies • Structure your code as you like • Supports Gradle and Maven • Common non-‐functional requirements for a "real" application – embedded servers, – security, metrics, health checks – externalised configuration
- 5. Rapid Prototyping : Spring CLI • Quickest way to get a spring app off the ground • Allows you to run groovy scripts without much boilerplate code • Not recommended for production Install using GVM $ gvm install springboot Running groovy scripts $ spring run app.groovy $ spring run --watch app.groovy $ spring test tests.groovy
- 6. A quick web application using spring boot app.groovy @Controller class Example { @RequestMapping("/") @ResponseBody public String helloWorld() { "Hello Spring boot audience!!!" } } $ spring run app.groovy
- 7. What Just happened? // import org.springframework.web.bind.annotation.Controller // other imports ... // @Grab("org.springframework.boot:spring-‐boot-‐web-‐starter:0.5.0") // @EnableAutoConfiguration @Controller class Example { @RequestMapping("/") @ResponseBody public String hello() { return "Hello World!"; } // public static void main(String[] args) { // SpringApplication.run(Example.class, args); // } }
- 8. Starter POMs • One-‐stop-‐shop for all the Spring and related technology • A set of convenient dependency descriptors • Contain a lot of the dependencies that you need to get a project up and running quickly • All starters follow a similar naming pattern; – spring-‐boot-‐starter-‐* • Examples – spring-‐boot-‐starter-‐web – spring-‐boot-‐starter-‐data-‐rest – spring-‐boot-‐starter-‐security – spring-‐boot-‐starter-‐amqp – spring-‐boot-‐starter-‐data-‐jpa – spring-‐boot-‐starter-‐data-‐elasticsearch – spring-‐boot-‐starter-‐data-‐mongodb – spring-‐boot-‐starter-‐actuator
- 9. Demo : Starter POMs @Grab('spring-‐boot-‐starter-‐security') @Grab('spring-‐boot-‐starter-‐actuator') @Controller class Example { @RequestMapping("/") @ResponseBody public String helloWorld() { return "Hello Audience!!!" } } //security.user.name : default 'user' //security.user.password : see log for auto generated password //actuator endpoints: /beans, /health, /mappings, /metrics etc.
- 10. Building using Gradle 10
- 11. Lets go beyond prototyping : Gradle Image source : http://www.drdobbs.com/jvm/why-‐build-‐your-‐java-‐projects-‐with-‐gradle/240168608
- 12. build.gradle task hello << { println "Hello !!!!" } task greet <<{ println "Welocome Mr. Kumar" } task intro(dependsOn: hello) << { println "I'm Gradle" } hello << { println "Hello extended!!!!" } greet.dependsOn hello, intro // gradle tasks :list all the available tasks // gradle intro :executes intro task // gradle -‐q greet :bare build output // gradle -‐-‐daemon hello :subsequent execution will be fast
- 13. build.gradle : using plugin and adding dependencies apply plugin: "groovy" //look for sources in src/main/groovy folder //inherits java plugin: src/main/java folder // tasks compileJava, compileGroovy, build, clean sourceCompatibility = 1.6 repositories { mavenCentral() } dependencies { compile 'org.codehaus.groovy:groovy-‐all:2.3.6' compile "org.apache.commons:commons-‐lang3:3.0.1" testCompile "junit:unit:4.+" }
- 14. build.gradle: for Spring boot app with hot reloading apply plugin: 'groovy' apply plugin: 'idea' apply plugin: 'spring-‐boot' buildscript { repositories { mavenCentral()} dependencies { classpath("org.springframework.boot:spring-‐boot-‐gradle-‐plugin:1.1.8.RELEASE") classpath 'org.springframework:springloaded:1.2.0.RELEASE' } } idea { module { inheritOutputDirs = false outputDir = file("$buildDir/classes/main/") } } repositories { mavenCentral() } dependencies { compile 'org.codehaus.groovy:groovy-‐all' compile 'org.springframework.boot:spring-‐boot-‐starter-‐web' }
- 15. Environment and Profile aka Grails config • Put application.properties/application.yml somewhere in classpath • Easy one: src/main/resources folder 15 application.yml app: name: Springboot+Config+Yml+Demo version: 1.0.0 server: port: 8080 settings: counter: 1 -‐-‐-‐ spring: profiles: development server: port: 9001 application.properties app.name=Springboot+Config+Demo app.version=1.0.0 server.port=8080 settings.coutner=1 application-‐development.properties app.name=Springboot+Config+Demo app.version=1.0.0 server.port=8080
- 16. Binding properties 16 Using ConfigurationProperties annotation import org.springframework.boot.context.properties.ConfigurationProperties import org.springframework.stereotype.Component @Component @ConfigurationProperties(prefix = "app") class AppInfo { String name String version } Using Value annotation import org.springframework.beans.factory.annotation.Value import org.springframework.stereotype.Component @Component class AppConfig { @Value('${app.name}') String appName @Value('${server.port}') Integer port }
- 17. Examples 17 OS env variable export SPRING_PROFILES_ACTIVE=development export SERVER_PORT=8090 gradle bootRun java -‐jar build/libs/demo-‐1.0.0.jar with a -‐D argument (remember to put it before the main class or jar archive) java -‐jar -‐Dspring.profiles.active=development build/libs/dem-‐1.0.0.jar java -‐jar -‐Dserver.port=8090 build./libs/demo-‐1.0.0.jar
- 18. Using Spring data • Add dependency compile 'org.springframework.boot:spring-‐boot-‐starter-‐data-‐mongodb' • Configure database URL spring.data.mongodb.uri=mongodb://localhost/springtestdev • Add entity class import org.springframework.data.annotation.Id; class • Add Person{@Id String id, String name} repository interface import org.springframework.data.mongodb.repository.MongoRepository public interface PersonRepository extends • Autowire and use like charm MongoRepository<Person, String> {} @Autowired PersonRepository personRepository personRepository.save(new Person(name:'Spring Boot')) personRepository.findAll() personRepository.count()
- 19. Next level persistence with GORM • Add dependencies to use GORM-‐Hibernate • For GORM MongoDB use the following dependencies compile 'org.grails:gorm-‐mongodb-‐spring-‐boot:1.1.0.RELEASE' • Add entity with @grails.persistence.entity 19 compile 'org.springframework.boot:spring-‐boot-‐starter-‐data-‐jpa' compile 'org.grails:gorm-‐hibernate4-‐spring-‐boot:1.1.0.RELEASE' runtime 'com.h2database:h2' //for h2 database import grails.persistence.Entity @Entity class Person { String name; Integer age static constraints = { name blank: false age min: 15 } } Further reading https://github.com/grails/grails-‐data-‐mapping
- 20. Server side view template libraries • JSP/JSTL • Thymeleaf • Freemarker • Velocity • Tiles • GSP • Groovy Template Engine 20
- 21. • Very limited existing tags available • https://github.com/grails/grails-‐boot/issues/3 • Add dependency • Put GSP templates in resources/templates folder GSP 21 compile "org.grails:grails-‐gsp-‐spring-‐boot:1.0.0.RC1" compile "org.grails:grails-‐web:2.4.0.M2"
- 22. GSP continued... • Sample request handler 22 @RequestMapping("/show/{id}") public ModelAndView show(@PathVariable Long id) { Person person = Person.read(id) if (person) { //render(view:"/person/show", model:[personInstance:personInstance]) new ModelAndView("/person/show", [personInstance: Person.get(id)]) } else { log.info "No entity fount for id : " + id //redirect(controller:"person", action:"list") new ModelAndView("redirect:/person/list") } }
- 23. Grails Taglib 23 @grails.gsp.TagLib @org.springframework.stereotype.Component class ApplicationTagLib { static namespace = "app" def paginate = { attrs -‐> String action = attrs.action Integer total = attrs.total Integer currentPage = attrs.currentPage ?: 1 Integer pages = (total / 10) + 1 out << render(template: "/shared/pagination", model: [action: action, total: total, currentPage: currentPage, pages: pages] ) } } <app:paginate total="${personInstanceCount ?: 0}" currentPage="${currentPage}" action="/person/list"/>
- 24. Packaging executable jar and war files 24 Packaging as jar with embedded tomcat $ gradle build $ java -‐jar build/libs/mymodule-‐0.0.1-‐SNAPSHOT.jar Packaging as war : configure build.groovy //... apply plugin: 'war' war { baseName = 'myapp' version = '0.5.0' } //.... configurations { providedRuntime } dependencies { compile("org.springframework.boot:spring-‐boot-‐starter-‐web") providedRuntime("org.springframework.boot:spring-‐boot-‐starter-‐tomcat") // ... } $ gradle war
- 25. Q/A 25
- 26. Thank you. 26 Blog: http://www.intelligrape.com/blog/author/bhagwat LikedIn: http://www.linkedin.com/in/bhagwatkumar Twitter: http://twitter.com/bhagwatkumar Mail : [email protected]
- 27. References Samples : https://github.com/bhagwat/spring-‐boot-‐samples http://docs.spring.io/spring-‐boot/docs/current-‐SNAPSHOT/reference/htmlsingle http://docs.spring.io/spring-‐boot/docs/current-‐SNAPSHOT/reference/htmlsingle/#getting-‐ started-‐gvm-‐cli-‐installation https://github.com/spring-‐projects/spring-‐boot/tree/master/spring-‐boot-‐cli/samples http://docs.spring.io/spring-‐boot/docs/current-‐SNAPSHOT/reference/htmlsingle/#using-‐boot-‐ starter-‐poms http://spring.io/guides/gs/accessing-‐mongodb-‐data-‐rest/ https://spring.io/guides/gs/accessing-‐data-‐mongodb/ https://spring.io/guides/gs/accessing-‐data-‐jpa/ http://www.gradle.org/ http://www.slideshare.net/Soddino/developing-‐an-‐application-‐with-‐spring-‐boot-‐34661781 http://presos.dsyer.com/decks/spring-‐boot-‐intro.html http://pygments.org/ for nicely formatting code snippets included in presentation 27