Spring Boot Example

This project provides an opinionated example of Spring Boot. In addition to exercising basic features of the framework, it also makes some choices regarding included libraries.

Requirements

• Java 8
• Gradle 3
• Docker

Features

Some off-the-shelf Spring libraries have been included within this project:

• Spring Web for generating RESTful responses.
• Spring Actuator to provide runtime health checks. Detailed responses are unavailable in a production environment without authentication.
• Spring DevTools to restart a running server following recompilation. It is included as a development feature only and is not exported in the distribution.
• Spring Boot Test for auto-configuration of the application during testing. It also adds dependencies for JUnit 4, Hamcrest, and
• Spring Boot Gradle plugin for including runtime dependencies in the build artifact. Mockito. While AssertJ would normally be among that list, it has been omitted here.

This project replaces the internal Tomcat container with Jetty; the former is excluded from the build.

Building

If the Gradle wrapper has been generated, the project can be built in the usual way:

./gradlew clean build

If not then Gradle itself is required.

Thanks to the Spring Boot Gradle plugin, the build task will create a fat Jar at build/libs/mw-spring-boot-example-1.0-SNAPSHOT.jar that includes the necessary runtime dependencies.

To run the server with a watcher that will restart it when items on the classpath are rebuilt, use the bootRun task:

./gradlew bootRun

To specify the configuration profile, pass the name to the spring.profiles.active configuration variable. For example, to run in production:

./gradlew bootRun -Dspring.profiles.active=production

Deployment

A Docker configuration has been provided layered over Alpine. It exposes the application on port 8080.

To build a new image, run:

docker build -t spring-boot/example .

To run it, use:

docker run -p 8080:8080 spring-boot/example:latest

Endpoints

The server binds to localhost on port 8080. The Hello World example is at:

http://localhost:8080/hello

To personalise this, add the name in another path segment:

http://localhost:8080/hello/Foo