Spring Initializr provides an extensible API to generate quickstart projects. It also provides a configurable service: you can see our default instance at https://start.spring.io. It provides a simple web UI to configure the project to generate and endpoints that you can use via plain HTTP.
Spring Initializr also exposes an endpoint that serves its metadata in a well-known format to allow third-party clients to provide the necessary assistance.
Finally, Initializr offers a configuration structure to define all the aspects related to the project to generate: list of dependencies, supported java and boot versions, etc. Check the configuration of our instance for an example. Such configuration is also described in details on the wiki.
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Note
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We use the continuous deployment technique to manage our instance; check the milestones page for an overview of changes |
Spring Initializr has the following modules:
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initializr-generator: standalone project generation library that can be reused in many environments (including embedded in your own project) -
initializr-web: REST endpoints and web interface -
initializr-actuator: optional module to provide statistics and metrics on project generation
initializr-service is an additional module that represents the production instance that
is available at https://start.spring.io. It is not enabled by default but you can
enable the full profile in your IDE to easily run it locally.
Spring Initializr can be used as follows:
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With your browser (i.e. https://start.spring.io)
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In your IDE if you are using STS, IntelliJ IDEA Ultimate or NetBeans (with this plugin)
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On the command-line with the Spring Boot CLI or simply with
cURLorHTTPie
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Tip
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You can "curl" an instance to get a usage page with examples (try |
If you click on "Generate Project" on the web ui of our instance, it will download a project archive with a Maven-based project and the necessary infrastructure to start a basic Spring Boot app.
You could achieve the same result with a simple curl command
$ curl https://start.spring.io/starter.zip -o demo.zipThe web ui exposes a bunch of options that you can configure. These are mapped to the following request attributes:
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Basic information for the generated project:
groupId,artifactId,version,name,descriptionandpackageName-
The
nameattribute is also used to generate a default application name. The logic is that the name of the application is equal to thenameattribute with anApplicationsuffix (unless said suffix is already present). Of course, if the specified name contains an invalid character for a java identifier,Applicationis used as fallback. -
The
artifactIdattribute not only defines the identifier of the project in the build but also the name of the generated archive.
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dependencies(orstyle): the identifiers of the dependencies to add to the project. Such identifiers are defined through configuration and are exposed in the metadata. -
type: the kind of project to generate (e.g.maven-project). Again, each service exposes an arbitrary number of supported types and these are available in the metadata. -
javaVersion: the language level (e.g.1.8). -
bootVersion: the Spring Boot version to use (e.g.1.2.0.RELEASE). -
language: the programming language to use (e.g.java). -
packaging: the packaging of the project (e.g.jar). -
applicationName: the name of the application class (inferred by thenameattribute by default). -
baseDir: the name of the base directory to create in the archive. By default, the project is stored in the root.
This command generates an another-project directory holding a Gradle web-based
Groovy project using the actuator:
$ curl https://start.spring.io/starter.tgz -d dependencies=web,actuator \
-d language=groovy -d type=gradle-project -d baseDir=another-project | tar -xzvf -|
Note
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The /starter.tgz endpoint offers the same feature as /starter.zip but generates
a compressed tarball instead.
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You could use this infrastructure to create your own client since the project is generated via a plain HTTP call.
You can share or bookmark URLs that will automatically customize form inputs. For instance,
the following URL from the default instance uses groovy by default and set the name
to Groovy Sample:
https://start.spring.io/#!language=groovy&name=Groovy%20SampleThe following hashbang parameters are supported: type, groupId, artifactId, name,
description, packageName, packaging, javaVersion and language. Review the section
above for a description of each of them.
The service metadata is used by the web UI and is exposed to ease the creation of third-party clients. You can grab the metadata by curling the root
$ curl -H 'Accept: application/json' https://start.spring.io|
Note
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As stated above, if you use curl without an accept header, you’ll retrieve a human
readable text version of the metadata. HTTPie is also supported.
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The metadata basically lists the capabilities of the service, that is the available
options for all request parameters (dependencies, type, bootVersion, etc.) The web
UI uses that information to initialize the select options and the tree of available
dependencies.
The metadata also lists the default values for simple text parameter (i.e. the default
name for the project).
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Note
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More details about the structure of the metadata are available on the wiki. |
You can easily run your own instance. The initializr-web modules uses Spring Boot so when it
is added to a project, it will trigger the necessary auto-configuration to deploy the service.
You first need to create or update your configuration to define the necessary attributes that your instance will use. Again, check the wiki for a description of the configuration and review our own config for a sample.
You can integrate the library in a traditional Java-based project or by writing the super-simple script below
package org.acme.myapp
@Grab('io.spring.initializr:initializr-web:1.0.0.BUILD-SNAPSHOT')
@Grab('spring-boot-starter-web')
class YourInitializrApplication { }|
Note
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Spring Initializr is not available on Maven central yet so you will have to build it from source in order to use it in your own environment. |
Once you have created that script (my-instance.groovy), place your configuration in the same
directory and simply execute this command to start the service:
$ spring run my-instance.groovyYou may also want to run the default instance locally.
You need Java (1.8 or better), Maven 3.2+ and a bash-like shell.
Just invoke the build at the root of the project
$ mvn clean install
If you want to run the smoke tests using Geb, you need to enable the
smokeTests profile. Firefox should also be installed on your machine:
$ mvn verify -PsmokeTests
If you want to build both the library and the service, you can enable the full profile:
$ mvn clean install -Pfull
Once you have built the library, you can easily start the app as any other
Spring Boot app from the initializr-service directory:
$ cd initializr-service $ mvn spring-boot:run
You should be able to import the projects into your IDE with no
problems (STS with the m2e Groovy compiler support or IntelliJ IDEA
definitely work). Once there you can run the initializr-service from
its main method, debug it, and it will reload if you make changes to
other modules. (You may need to manually enable the "full" profile.)
This is the recommended way to operate while you are developing the
application, especially the UI.
If you are on a Mac and using homebrew, install the Cloud Foundry CLI:
$ brew install cloudfoundry-cli
Alternatively, download a suitable binary for your platform from Pivotal Web Services.
You should ensure that the application name and URL (name and host values) are suitable for
your environment before running cf push.
First, make sure that you have built the library, then make sure first that the jar has been created:
$ cd initializr-service $ mvn package
Once the jar has been created, you can push the application:
$ cf push your-initializr -p target/initializr-service.jar
Spring Initializr is Open Source software released under the Apache 2.0 license.