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 companion project that defines https://start.spring.io and, in particular, the configuration of our instance for an example. Such configuration is also described in details in the documentation.
Note
|
Check the milestones page for an overview of the changes. |
Installation and Getting Started
The reference documentation is available in HTML format.
Modules
Spring Initializr has the following modules:
-
initializr-generator
: core project generation library -
initializr-metadata
: metadata infrastructure for various aspects of the project -
initializr-generator-spring
: optional module defining the conventions for a Spring Boot project. Can be replaced by your own conventions if necessary. -
initializr-web
: REST endpoints and web interface -
initializr-actuator
: optional module to provide additional information and statistics on project generation -
initializr-docs
: documentation
Supported interfaces
Spring Initializr can be used as follows:
-
With your browser (i.e. https://start.spring.io)
-
In your IDE if you are using STS, IntelliJ IDEA Ultimate or NetBeans (with this plugin)
-
On the command-line with the Spring Boot CLI or simply with
cURL
orHTTPie
Tip
|
You can "curl" an instance to get a usage page with examples (try
|
Generating a project
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.zip
The web ui exposes a bunch of options that you can configure. These are mapped to the following request attributes:
-
Basic information for the generated project:
groupId
,artifactId
,version
,name
,description
andpackageName
-
The
name
attribute is also used to generate a default application name. The logic is that the name of the application is equal to thename
attribute with anApplication
suffix (unless said suffix is already present). Of course, if the specified name contains an invalid character for a java identifier,Application
is used as fallback. -
The
artifactId
attribute not only defines the identifier of the project in the build but also the name of the generated archive.
-
-
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 thename
attribute 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
|
The /starter.tgz endpoint offers the same feature as /starter.zip but
generates a compressed tarball instead.
|
You could use this infrastructure to create your own client since the project is generated via a plain HTTP call.
Customize form inputs
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%20Sample
The 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.
Service metadata
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
|
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:
|
$ http https://start.spring.io Accept:application/json
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).
Note
|
More details about the structure of the metadata are available in the documentation. |
Running your own instance
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 documentation 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.groovy
You may also want to run the default instance locally.
Building from Source
You need Java 1.8 and a bash-like shell.
Building
Just invoke the build at the root of the project
$ ./mvnw clean install
To generate the docs as well, you should enable the full
profile:
$ ./mvnw clean install -Pfull
License
Spring Initializr is Open Source software released under the Apache 2.0 license.