Spring Boot (1.x) Overview/Intro
by Dominik Dorn @ Java-Vienna April Meetup
#Java #Vienna 16 April 2018 | Spring Boot Overview/Intro | Dominik Dorn @domdorn

Dominik Dorn
4 Freelance Software Engineer
4 Leader of
4 Java-Vienna Meetup
4 PlayFramework.Wien
Meetup
#Java, #Scala, #Akka, #Play,
#Cassandra, #Kafka,#PostgreSQL
Reach out! Xing / Twitter / LinkedIn
2

Overview
4 What's Spring-Boot
4 Getting started
4 REST-Endpoints / Testing
4 Day2day Work / Production Usage
#Java #Vienna 16 April 2018 | Spring Boot Overview/Intro | Dominik Dorn @domdorn 3

What is Spring-Boot?
4 Running an embedded Webserver ( WAR possible )
4 Classpath Scanning / Reflection++
4 Convention over Configuration
4 99.8% 08/15-Spring Programming
4 Security, Templating, Data-Access, etc.
#Java #Vienna 16 April 2018 | Spring Boot Overview/Intro | Dominik Dorn @domdorn 4

Maven
<project ...>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.12.RELEASE</version>
</parent>
...
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>
</project>
#Java #Vienna 16 April 2018 | Spring Boot Overview/Intro | Dominik Dorn @domdorn 5

Application Entrypoint
@Configuration
@EnableAutoConfiguration
@ComponentScan
public class MyApp {
public static void main(String[] args) throws Exception {
ConfigurableApplicationContext app = SpringApplication
.run(MyApp.class, args);
}
}
#Java #Vienna 16 April 2018 | Spring Boot Overview/Intro | Dominik Dorn @domdorn 6

Application Entrypoint
@SpringBootApplication
public class MyApp {
public static void main(String[] args) throws Exception {
ConfigurableApplicationContext app = SpringApplication
.run(MyAppConfiguration.class, args);
// -----------^^^^^^^^^^^^^^^^^<-- look here!
}
}
#Java #Vienna 16 April 2018 | Spring Boot Overview/Intro | Dominik Dorn @domdorn 7

First Rest Controller
@RestController
public class FrontpageController {
@RequestMapping("/")
public String index() {
return "Hello Java Vienna!";
}
}
#Java #Vienna 16 April 2018 | Spring Boot Overview/Intro | Dominik Dorn @domdorn 8

Path Parameters
@RestController
public class FrontpageController {
@RequestMapping("/hello/{who}")
public String hello(@PathVariable String who){
return "Hello " + who;
}
}
#Java #Vienna 16 April 2018 | Spring Boot Overview/Intro | Dominik Dorn @domdorn 9

Query Parameters
@RestController
public class FrontpageController {
@RequestMapping("/greet/{who}")
public String greet(@PathVariable String who,
@RequestParam(name = "greeting",
defaultValue = "Hello")
String greeting) {
return greeting + " " + who;
}
}
#Java #Vienna 16 April 2018 | Spring Boot Overview/Intro | Dominik Dorn @domdorn 10

#Java #Vienna 16 April 2018 | Spring Boot Overview/Intro | Dominik Dorn @domdorn 11

Handling different clients
@RequestMapping(value = "/", consumes = "application/json",
produces = "application/json" )
public Map indexJson(
@RequestParam(
value = "who", defaultValue = "world") String who) {
Map<String, String> m = new HashMap<>();
m.put("greeting", "hello");
m.put("who", who);
return m;
}
#Java #Vienna 16 April 2018 | Spring Boot Overview/Intro | Dominik Dorn @domdorn 12

#Java #Vienna 16 April 2018 | Spring Boot Overview/Intro | Dominik Dorn @domdorn 13

Testing
#Java #Vienna 16 April 2018 | Spring Boot Overview/Intro | Dominik Dorn @domdorn 14

Maven
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
</dependency>
#Java #Vienna 16 April 2018 | Spring Boot Overview/Intro | Dominik Dorn @domdorn 15

@RunWith(SpringRunner.class)
@SpringBootTest(
webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT,
classes = MyApp.class)
public class FrontpageControllerTest {
@Autowired
TestRestTemplate rest;
@Test
public void helloJavaVienna() throws Exception {
String result = rest.getForObject("/hello/java-vienna", String.class);
Assert.assertEquals("Hello java-vienna", result);
}
}
#Java #Vienna 16 April 2018 | Spring Boot Overview/Intro | Dominik Dorn @domdorn 16

@RunWith(SpringRunner.class)
@SpringBootTest(
webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT,
classes = MyApp.class)
@AutoConfigureMockMvc
public class MVCFrontpageControllerTest {
@Autowired
MockMvc mvc;
@Test
public void helloJavaVienna() throws Exception {
mvc.perform(MockMvcRequestBuilders
.get("/hello/{who}", "java-vienna"))
.andExpect(status().is2xxSuccessful())
.andExpect(content().string("Hello java-vienna"));
}
}
#Java #Vienna 16 April 2018 | Spring Boot Overview/Intro | Dominik Dorn @domdorn 17

Dev-Workflow
#Java #Vienna 16 April 2018 | Spring Boot Overview/Intro | Dominik Dorn @domdorn 18

JRebel
4 Pro: Fastest turnaround ( ~ 1-3 seconds )
4 Contra: 550 USD / year
#Java #Vienna 16 April 2018 | Spring Boot Overview/Intro | Dominik Dorn @domdorn 19

Spring Dev-Tools
4 Pro: Free, includes LiveReload (for browser reload)
4 Contra: Restarts whole application every time
classpath changes ( 2 - 30+ seconds )
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<optional>true</optional>
</dependency>
</dependencies>
#Java #Vienna 16 April 2018 | Spring Boot Overview/Intro | Dominik Dorn @domdorn 20

Deploying
#Java #Vienna 16 April 2018 | Spring Boot Overview/Intro | Dominik Dorn @domdorn 21

<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<version>1.5.13.BUILD-SNAPSHOT</version>
<executions>
<execution>
<goals>
<goal>repackage</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
#Java #Vienna 16 April 2018 | Spring Boot Overview/Intro | Dominik Dorn @domdorn 22

java -jar target/myApp.jar
#Java #Vienna 16 April 2018 | Spring Boot Overview/Intro | Dominik Dorn @domdorn 23

#Java #Vienna 16 April 2018 | Spring Boot Overview/Intro | Dominik Dorn @domdorn 24

<plugin>
<groupId>com.spotify</groupId>
<artifactId>docker-maven-plugin</artifactId>
<version>1.0.0</version>
<configuration>
<imageName>domdorn/${project.artifactId}</imageName>
<dockerDirectory>src/main/docker</dockerDirectory>
<resources>
<resource>
<targetPath>/</targetPath>
<directory>${project.build.directory}</directory>
<include>${project.build.finalName}.jar</include>
</resource>
</resources>
</configuration>
</plugin>
#Java #Vienna 16 April 2018 | Spring Boot Overview/Intro | Dominik Dorn @domdorn 25

Prod-Monitoring: Actuator
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
</dependencies>
#Java #Vienna 16 April 2018 | Spring Boot Overview/Intro | Dominik Dorn @domdorn 26

Endpoint Description
auditevents Exposes audit events information for
the current application.
beans Displays a complete list of all the
Spring beans in your application.
configprops Displays a collated list of all
@ConfigurationProperties
env Exposes properties from Spring’s
ConfigurableEnvironment.
#Java #Vienna 16 April 2018 | Spring Boot Overview/Intro | Dominik Dorn @domdorn 27

Endpoint Description
flyway / liquibase Shows any Flyway/Liquibase database
migrations that have been applied.
health Shows application health information.
httptrace Displays the last 100 HTTP req./resp.
exchanges
loggers Show application loggers and
reconfigure them
#Java #Vienna 16 April 2018 | Spring Boot Overview/Intro | Dominik Dorn @domdorn 28

Endpoint Description
metrics Shows ‘metrics’ information for the
current application.
mappings Displays a collated list of all
@RequestMapping paths.
scheduledtasks Displays the scheduled tasks in your
application.
threaddump / heapdump Performs a thread dump / heap dump
(gzipped).
#Java #Vienna 16 April 2018 | Spring Boot Overview/Intro | Dominik Dorn @domdorn 29

THANK YOU!
Blog https://dominikdorn.com
Twitter @domdorn
Xing https://www.xing.com/profile/Dominik_Dorn
LinkedIn https://www.linkedin.com/in/dominik-dorn
Java-Vienna Meetup | PlayFramework.Wien Meetup
#Java #Vienna 16 April 2018 | Spring Boot Overview/Intro | Dominik Dorn @domdorn 31