5.1 KiB
Spring Bootstrap Services
Minimum fuss for getting RESTful services up and running in production, and in other environments.
Feature | Implementation | Notes |
---|---|---|
Server | Tomcat or Jetty | Whatever is on the classpath |
REST | Spring MVC | |
Security | Spring Security | If on the classpath |
Logging | Logback, Log4j or JDK | Whatever is on the classpath. Sensible defaults. |
Database | HSQLDB or H2 | Per classpath, or define a DataSource to override |
Externalized configuration | Properties or YAML | Support for Spring profiles. Bind automatically to @Bean. |
Validation | JSR-303 | |
Management endpoints | Spring MVC | Health, basic metrics, request tracing, shutdown |
Error pages | Spring MVC | Sensible defaults based on exception and status code |
JSON | Jackson 2 | |
ORM | Spring Data JPA | If on the classpath |
Batch | Spring Batch | If enabled and on the classpath |
Integration Patterns | Spring Integration | If on the classpath |
Getting Started
You will need Java (6 at least) and a build tool (Maven is what we use below, but you are more than wecome to use gradle). These can be downloaded or installed easily in most operating systems. FIXME: short instructions for Mac and Linux.
A basic project
If you are using Maven create a really simple pom.xml
with 2 dependencies:
<project>
<modelVersion>4.0.0</modelVersion>
<groupId>com.mycompany</groupId>
<artifactId>myproject</artifactId>
<version>1.0.0-SNAPSHOT</version>
<packaging>jar</packaging>
<parent>
<groupId>org.springframework.bootstrap</groupId>
<artifactId>spring-bootstrap-applications</artifactId>
<version>0.0.1-SNAPSHOT</version>
</parent>
<properties>
<spring.bootstrap.version>0.0.1-SNAPSHOT</spring.bootstrap.version>
<start-class>org.springframework.bootstrap.SpringApplication</start-class>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.bootstrap</groupId>
<artifactId>spring-bootstrap-web-application</artifactId>
<version>${spring.bootstrap.version}</version>
</dependency>
<dependency>
<groupId>org.springframework.bootstrap</groupId>
<artifactId>spring-bootstrap-service</artifactId>
<version>${spring.bootstrap.version}</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-shade-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
If you like Gradle, that's fine, and you will know what to do with those dependencies. The first dependency adds Spring Bootstrap auto configuration and the Jetty container to your application, and the second one adds some more opinionated stuff like the default management endpoints. If you prefer Tomcat FIXME: use a different dependency.
You should be able to run it already:
$ mvn package
$ java -jar target/myproject-1.0.0-SNAPSHOT.jar
Then in another terminal
$ curl localhost:8080/healthz
ok
$ curl localhost:8080/varz
{"counter.status.200.healthz":1.0,"gauge.response.healthz":10.0,"mem":120768.0,"mem.free":105012.0,"processors":4.0}
/healthz
is the default location for the health endpoint - it tells
you if the application is running and healthy. /varz
is the default
location for the metrics endpoint - it gives you basic counts and
response timing data by default but there are plenty of ways to
customize it.
$ curl localhost:8080/
{"status": 404, "error": "Not Found", "message": "Not Found"}
That's OK, we haven't added any business content yet.
Adding a business endpoint
To do something useful to your business you need to add at least one
endpoint. An endpoint can be implemented as a Spring MVC
@Controller
, e.g.
@Controller
@EnableAutoConfiguration
public class SampleController {
@RequestMapping("/")
@ResponseBody
public Map<String, String> helloWorld() {
return Collections.singletonMap("message", "Hello World");
}
public static void main(String[] args) throws Exception {
SpringApplication.run(SampleController.class, args);
}
}
You can launch that straight away using the Spring Bootstrap CLI
(without the @EnableAutoConfiguration
and even without the import
statements that your IDE will add if you are using one), or you can
use the main method to launch it from your project jar. Just change
the start-class
in the pom
above to the fully qualified name of
your SampleController
, e.g.
<start-class>com.mycompany.sample.SampleController</start-class>
and re-package:
$ mvn package
$ java -jar target/myproject-1.0.0-SNAPSHOT.jar
$ curl localhost:8080/
{"message": "Hello World"}
Add a database
Just add spring-jdbc
and an embedded database to your dependencies:
FIXME: TBD