Boost Spring Boot Project Generation with Alibaba’s start.aliyun.com and Spring Initializr

Background

Many developers use start.spring.io to bootstrap Spring Boot projects, which offers a rich set of components and packaging options. Recently, Alibaba's Nacos and Sentinel were added to the options, but the generated skeleton only contains component coordinates without usage examples, requiring developers to search for tutorials and risking version mismatches.

Goal and New Site

To make Alibaba Cloud the most developer‑friendly cloud for Java, the team created start.aliyun.com , which builds on Spring Initializr while adding demo code, configuration samples, and integrated component documentation.

Core Features of start.aliyun.com

Individual demo code and configuration samples for each component.

Built‑in project documentation to reduce the need for external docs.

A “subtract‑instead‑of‑add” approach for component usage.

Multi‑component integration solutions (in development).

Regular updates to keep up with the latest Spring Boot features.

Basic Usage

Include the Initializr BOM in your Maven build:

<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>

Then add the required modules, for example:

<dependency>
    <groupId>io.spring.initializr</groupId>
    <artifactId>initializr-generator-spring</artifactId>
</dependency>
<dependency>
    <groupId>io.spring.initializr</groupId>
    <artifactId>initializr-version-resolver</artifactId>
</dependency>
<dependency>
    <groupId>io.spring.initializr</groupId>
    <artifactId>initializr-web</artifactId>
</dependency>

Basic Configuration (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

Project types can also be defined:

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

Dependency Configuration

Define dependencies under initializr.dependencies with groups and content:

initializr:
  dependencies:
    - name: Web
      content:
        - name: Web
          id: web
          description: Full-stack web development with Tomcat and Spring MVC
        - name: Developer Tools
          content:
            - name: Spring Boot DevTools
              id: devtools
              groupId: org.springframework.boot
              artifactId: spring-boot-devtools
              description: Provides fast application restarts, LiveReload, and configurations for enhanced development experience.
            - name: Lombok
              id: lombok
              groupId: org.projectlombok
              artifactId: lombok
              description: Java annotation library which helps to reduce boilerplate code.

Each dependency includes id, groupId, artifactId, name, description and optional version.

Version Ranges

Version ranges use Maven‑style interval notation, e.g. [1.1.6.RELEASE,1.3.0.M1) includes the lower bound but excludes the upper bound. A single version like 1.2.0.RELEASE means that version and any later ones. The x placeholder can be used for the latest release in a series, e.g. 1.4.x.BUILD-SNAPSHOT.

Compatibility Range

When a component’s version depends on the Spring Boot version, use compatibilityRange either directly on the component or inside a mappings block to adjust the artifactId per Boot version.

BOM Management

Define a BOM under initializr.env.boms and reference it in a dependency:

initializr:
  env:
    boms:
      my-api-bom:
        groupId: org.acme
        artifactId: my-api-dependencies
        version: 1.0.0.RELEASE
        repositories: my-api-repo-1

initializr:
  dependencies:
    - name: Other
      content:
        - name: My API
          id: my-api
          groupId: org.acme
          artifactId: my-api
          bom: my-api-bom

Advanced Customization

Enable Caching

Add cache dependencies and annotate the main class with @EnableCaching:

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

Adding Demo Code

Register a custom ProjectContributor via spring.factories to generate demo files when a specific component is selected:

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

Example contributor:

@ProjectGenerationConfiguration
public class SpringCloudAlibabaProjectGenerationConfiguration {
    private final InitializrMetadata metadata;
    private final ProjectDescription description;
    private final IndentingWriterFactory indentingWriterFactory;
    private final TemplateRenderer templateRenderer;
    public SpringCloudAlibabaProjectGenerationConfiguration(InitializrMetadata metadata,
                                                            ProjectDescription description,
                                                            IndentingWriterFactory indentingWriterFactory,
                                                            TemplateRenderer templateRenderer) {
        this.metadata = metadata;
        this.description = description;
        this.indentingWriterFactory = indentingWriterFactory;
        this.templateRenderer = templateRenderer;
    }
    @Bean
    @ConditionalOnRequestedDependency("sca-oss")
    public OSSDemoCodeContributor ossContributor() {
        return new OSSDemoCodeContributor(description, templateRenderer);
    }
    // ... other contributors
}

The contributor renders a Mustache template and writes the generated file to the project directory.

Principles of Spring Initializr

Startup Phase

The application loads configuration, initializes metadata providers, creates the template engine, and registers web endpoints. The main auto‑configuration class is InitializrAutoConfiguration, which sets up beans such as ProjectDirectoryFactory, IndentingWriterFactory, and MustacheTemplateRenderer.

Generation Phase

For each request, a new ProjectGenerationContext (a child of the main application context) is created. The context registers a ProjectDescription provider, configuration classes, and then invokes the ProjectGenerator, which delegates to a series of ProjectContributor implementations to write files such as pom.xml, source code, resources, and documentation.

Extension Points

Two main extension mechanisms are provided:

ProjectContributor : receives the project root path and can write any files (e.g., Maven pom, web folders, application.properties, main class, HELP.md).

Customizer : named components such as MainApplicationTypeCustomizer, BuildCustomizer, GitIgnoreCustomizer, etc., which adjust specific parts of the generated project before files are written.

Reference Links

Initializr documentation

Spring Initializr GitHub

start.spring.io GitHub