Spring Boot - By Vinay Prajapati

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@Controllerclass Example {

@RequestMapping("/")@ResponseBody public String helloWorld() {

"Hello Spring boot audience!!!"}

}

// import org.springframework.web.bind.annotation.Controller// other imports ...// @Grab("org.springframework.boot:spring-boot-web-starter:0.5.0")

// @EnableAutoConfiguration@Controllerclass Example { @RequestMapping("/") @ResponseBody public String hello() { return "Hello World!"; }

// public static void main(String[] args) {// SpringApplication.run(Example.class, args);// }}

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@Grab('spring-boot-starter-security')@Grab('spring-boot-starter-actuator')@Grab('spring-boot-starter-jetty')@Controllerclass Example {

@RequestMapping("/")@ResponseBodypublic String helloWorld() {

return "Hello Audience!!!"}

}

//security.user.name//security.user.password

//actuator endpoints: /beans, /health, /mappings, /metrics etc.

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' }}

repositories { mavenCentral() }

dependencies { compile 'org.codehaus.groovy:groovy-all' compile 'org.springframework.boot:spring-boot-starter-web'}

Exercise- Use actuator starter POM in gradle application just created

- Use security starter POM in gradle application just created

- Changing the default embedded servlet container and the port

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$ gradle build$ java -jar build/libs/mymodule-0.0.1-SNAPSHOT.jar

//...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

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app: name: Springboot+Config+Yml+Demo version: 1.0.0server: port: 8080settings: counter: 1---spring: profiles: developmentserver: port: 9001

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export SPRING_PROFILES_ACTIVE=developmentexport SERVER_PORT=8090gradle bootRunjava -jar build/libs/demo-1.0.0.jar

java -jar -Dspring.profiles.active=development build/libs/dem-1.0.0.jarjava -jar -Dserver.port=8090 build/libs/demo-1.0.0.jar

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import org.springframework.boot.context.properties.ConfigurationPropertiesimport org.springframework.stereotype.Component@Component@ConfigurationProperties(prefix = "app")class AppInfo { String name String version}

import org.springframework.beans.factory.annotation.Valueimport org.springframework.stereotype.Component@Componentclass AppConfig { @Value('${app.name}') String appName

@Value('${server.port}') Integer port}

1. A /config subdir of the current directory. 2. The current directory3. A classpath /config package4. The classpath root

Don’t forget commandLine. It’s the Master here.

2014-03-05 10:57:51.112 INFO 45469 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet Engine: Apache Tomcat/7.0.52

2014-03-05 10:57:51.253 INFO 45469 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext

$ java -jar myapp.jar --debug

logging.file logging.path Example Description

(none) (none) Console only logging.

Specific file (none) my.log Writes to the specified log file. Names can be an exact location or relative to the current directory.

(none) Specific directory /var/log Writes spring.log to the specified directory. Names can be an exact location or relative to the current directory.

logging.level.*: DEBUG_LEVEL

E.g.

logging.level.intellimeet: ERROR

ID Description Sensitive

autoconfig Displays an auto-configuration report showing all auto- configuration candidates and the reason why they ‘were’ or ‘were not’ applied.

true

beans Displays a complete list of all the Spring beans in your application. true

configprops Displays a collated list of all @ConfigurationProperties. true

dump Performs a thread dump. true

env Exposes properties from Spring’s ConfigurableEnvironment. true

health Shows application health information (a simple ‘status’ when accessed over an unauthenticated connection or full message details when authenticated).

false

info Displays arbitrary application info. false

metrics Shows ‘metrics’ information for the current application. true

mappings Displays a collated list of all @RequestMapping paths. true

shutdown Allows the application to be gracefully shutdown (not enabled by default). true

trace Displays trace information (by default the last few HTTP requests). true

The prefix #endpoints + . + name” is used to uniquely identify the endpoint that is being configured.

E.g.endpoints.beans.id=springbeans endpoints.beans.sensitive=false endpoints.shutdown.enabled=true

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compile 'mysql:mysql-connector-java:5.1.6'compile 'org.springframework.boot:spring-boot-starter-jdbc'compile 'org.springframework.boot:spring-boot-starter-data-jpa'

spring.datasource.url= jdbc:mysql://localhost/springbootspring.datasource.username=rootspring.datasource.password=rootspring.datasource.driverClassName=com.mysql.jdbc.Driverspring.jpa.hibernate.ddl-auto=create-drop

import javax.persistence.Entityimport javax.persistence.Idclass City{@Id String id, String name , String stateprotected City() {}public City(String name, String state) { this.name = name this.state = state}}

• import org.springframework.data.mongodb.repository.MongoRepository public interface CityRepository extends CrudRepository<City, Long> {}

•@Autowired CityRepository cityRepositorycityRepository.save(new City(id:'1',name: 'Noida',state: 'UP'))cityRepository.findAll()cityRepository.count()

(A Glimpse)•••••••

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compile "org.grails:grails-gsp-spring-boot:1.0.0.RC1" compile "org.grails:grails-web:2.4.0.M2"

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@RequestMapping("/show/{id}")public ModelAndView show(@PathVariable Long id) { Person person = Person.read(id) if (person) { new ModelAndView("/person/show", [personInstance: Person.get(id)]) } else { log.info "No entity fount for id : " + id new ModelAndView("redirect:/person/list") } }

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@grails.gsp.TagLib@org.springframework.stereotype.Componentclass 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"/>

- Messaging (JMS)- NOSQL / SQL database support- Mailing- Testing - Monitoring and Management using JMX- Hot Swapping - reloading content on run

time

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com +- example +- myproject +- Application.java(Main class) | +- domain

| +- Customer.java | +- CustomerRepository.java

| +- service

| +- CustomerService.java | +- web +- CustomerController.java

Fig.: Typical structure to be followed

Miscellaneous- Enabling Disabling the Banner

- Changing the Banner

(http://www.kammerl.de/ascii/AsciiSignature.php)

- Adding event Listeners

- Logging startup info

● Idea behind Spring Boot.● It’s key Features● Easy start with Spring Boot using CLI.● .● Using Spring boot with build tools - gradle, maven.● Packaging executable jar files / war files.● Environment AKA Profile● Persisting data using Spring Data ● Next level persistence using GORM● Creating Views a Glimpse● Some Misc.

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