Master Spring Initializr: From Basic Setup to Advanced Customization

Background

Many developers use start.spring.io to bootstrap Spring Boot projects, but the generated skeletons lack usage demos, requiring extra lookup.

Aliyun Extension

Alibaba launched start.aliyun.com, built on Spring Initializr, adding per‑component demo code, built‑in documentation, and multi‑component integration.

Usage Guide

1. Basic Usage

Introduce the framework via the BOM dependency.

<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>io.spring.initializr</groupId>
            <artifactId>initializr-bom</artifactId>
            <version>0.9.0.BUILD-SNAPSHOT</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>

Configure supported packagings, Java versions, and languages in application.yml:

initializr:
  packagings:
    - name: Jar
      id: jar
      default: true
    - name: War
      id: war
      default: false
  javaVersions:
    - id: 13
      default: false
    - id: 11
      default: false
    - id: 1.8
      name: 8
      default: true
  languages:
    - name: Java
      id: java
      default: true
    - name: Kotlin
      id: kotlin
      default: false
    - name: Groovy
      id: groovy
      default: false

Define project types (Maven/Gradle) and their actions.

initializr:
  types:
    - name: Maven Project
      id: maven-project
      description: Generate a Maven based project archive.
      tags:
        build: maven
        format: project
      default: true
      action: /starter.zip
    - name: Maven POM
      id: maven-build
      description: Generate a Maven pom.xml.
      tags:
        build: maven
        format: build
      default: false
      action: /pom.xml
    - name: Gradle Project
      id: gradle-project
      description: Generate a Gradle based project archive.
      tags:
        build: gradle
        format: project
      default: false
      action: /starter.zip
    - name: Gradle Config
      id: gradle-build
      description: Generate a Gradle build file.
      tags:
        build: gradle
        format: build
      default: false
      action: /build.gradle

2. Advanced Customization

Enable caching to avoid frequent metadata fetches.

<dependency>
  <groupId>javax.cache</groupId>
  <artifactId>cache-api</artifactId>
</dependency>
<dependency>
  <groupId>org.ehcache</groupId>
  <artifactId>ehcache</artifactId>
</dependency>

Add @EnableCaching on the main class.

Provide component‑specific demo code via ProjectContributor implementations and register them in spring.factories.

io.spring.initializr.generator.project.ProjectGenerationConfiguration=\
com.alibaba.alicloud.initializr.extension.dependency.springboot.SpringCloudProjectGenerationConfiguration

Underlying Principles

The framework separates a startup phase (metadata loading, bean registration) from a generation phase (a dedicated ProjectGenerationContext per request). The generation pipeline creates a context, registers a ProjectDescriptionProvider, applies ProjectDescriptionCustomizer s, and finally invokes a series of ProjectContributor s to write files such as pom.xml, source code, resources, and help documents.

Key extension points include ProjectContributor and various *Customizer interfaces (e.g., MainApplicationTypeCustomizer, BuildCustomizer, GitIgnoreCustomizer).

References

https://docs.spring.io/initializr/docs/current-SNAPSHOT/reference/html/

https://github.com/spring-io/initializr

https://github.com/spring-io/start.spring.io