Spring boot

Spring Boot
- By Vinay Prajapati

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@Controller
class 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
@Controller
class Example {
@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')
@Controller
class Example {
@ResponseBody
public 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: 1.0.0
server:
port: 8080
settings:
counter: 1
---
spring:
profiles: development
server:
port: 9001

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export SPRING_PROFILES_ACTIVE=development
export SERVER_PORT=8090
gradle bootRun
java -jar build/libs/demo-1.0.0.jar
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

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

1. A /config subdir of the current directory.
2. The current directory
3. A classpath /config package
4. 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/springboot
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.driverClassName=com.mysql.jdbc.Driver
spring.jpa.hibernate.ddl-auto=create-drop
import javax.persistence.Entity
import javax.persistence.Id
class City{@Id String id, String name , String state
protected City() {}
public City(String name, String state) {
this.name = name
this.state = state
}}

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import org.springframework.data.mongodb.repository.MongoRepository
public interface CityRepository extends CrudRepository<City, Long> {}
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@Autowired CityRepository cityRepository
cityRepository.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.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"/>

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

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.

Spring boot

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