The easiest way to develop and demonstrate Spring Boot's capabilities is using the Spring Boot CLI, a command-line tool. Perform the following steps:
spring-boot-cli-1.3.5.RELEASE-bin.zip
file from http://repo.spring.io/release/org/springframework/boot/spring-boot-cli/1.3.5.RELEASE/spring-boot-cli-1.3.5.RELEASE-bin.zip.bin
folder.Ensure that the bin
folder is added to the system path so that Spring Boot can be run from any location.
$spring –-version Spring CLI v1.3.5.RELEASE
myfirstapp.groovy
in any folder:@RestController class HelloworldController { @RequestMapping("/") String sayHello() { "Hello World!" } }
myfirstapp.groovy
is saved and execute the following command. The last few lines of the server start-up log will be similar to the following:$spring run myfirstapp.groovy 2016-05-09 18:13:55.351 INFO 35861 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : FrameworkServlet 'dispatcherServlet': initialization started 2016-05-09 18:13:55.375 INFO 35861 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : FrameworkServlet 'dispatcherServlet': initialization completed in 24 ms
http://localhost:8080
; the browser will display the following message:Hello World!
There is no war file created, and no Tomcat server was run. Spring Boot automatically picked up Tomcat as the webserver and embedded it into the application. This is a very basic, minimal microservice. The @RestController
annotation, used in the previous code, will be examined in detail in the next example.