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This page covers everything you need to add Storm to your project: prerequisites, dependency setup, and optional modules.
| Requirement | Version |
|---|---|
| JDK | 21 or later |
| Kotlin (if using Kotlin) | 2.0 or later |
| Build tool | Maven 3.9+ or Gradle 8+ |
| Database | Any JDBC-compatible database |
Kotlin users do not need any preview flags. Java users must enable --enable-preview in their compiler configuration because the Java API uses String Templates (JEP 430).
The Storm Gradle plugin collapses the whole setup into one plugin application. It imports the BOM, adds the core dependencies for your language, wires the metamodel processor, selects the Kotlin compiler-plugin variant matching your Kotlin version, and configures the Java preview flags. Requires Gradle 8.5+.
plugins {
kotlin("jvm") version "2.4.0"
id("com.google.devtools.ksp") version "2.3.10"
id("st.orm") version "@@STORM_VERSION@@"
}That is the entire Storm setup. KSP stays in your plugins block because its version is paired to your Kotlin version; when it is missing, the build fails with the exact line to add.
plugins {
java
id("st.orm") version "@@STORM_VERSION@@"
}That is the entire Storm setup, including the --enable-preview flags on compilation, tests, and execution that storm-java21's String Templates (JEP 430) require. Use a JDK 21 toolchain: preview class files are version-locked, so storm-java21 runs on JDK 21 exactly.
The plugin configures, per language path:
| Kotlin | Java | |
|---|---|---|
| BOM | storm-bom imported as a platform |
storm-bom imported as a platform |
| API | storm-kotlin |
storm-java21 |
| Engine | storm-core (runtime only) |
storm-core (runtime only) |
| Metamodel | storm-metamodel-ksp on ksp |
storm-metamodel-processor on annotationProcessor |
| Compiler plugin | storm-compiler-plugin-<variant> matching the Kotlin version |
— |
| Compiler flags | — | --enable-preview on compile, test, and exec tasks |
All Storm coordinates use the plugin's own version; the plugin and the artifacts are released together. Because the BOM is imported, optional modules stay version-less: runtimeOnly("st.orm:storm-postgresql") just works.
The storm { } extension covers the cases where the defaults do not fit:
storm {
metamodel.set(true) // metamodel generation (default true)
compilerPlugin.set(true) // Kotlin: Storm compiler plugin (default true)
compilerPluginVariant.set("2.4") // pin the variant, e.g. for a newer Kotlin than the plugin knows
javaPreview.set(true) // Java: --enable-preview flags (default true)
}In mixed Kotlin/Java projects the Kotlin path wins: KSP processes Java declarations too. If you specifically need the Java annotation processor as well, add annotationProcessor("st.orm:storm-metamodel-processor") manually.
Maven users and Gradle users who prefer explicit configuration continue with the manual setup below.
Storm provides a Bill of Materials (BOM) for centralized version management. Import the BOM once, then omit version numbers from individual Storm dependencies. This prevents version mismatches between modules.
dependencies {
implementation(platform("st.orm:storm-bom:@@STORM_VERSION@@"))
}Maven:
<dependencyManagement>
<dependencies>
<dependency>
<groupId>st.orm</groupId>
<artifactId>storm-bom</artifactId>
<version>@@STORM_VERSION@@</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>Gradle (Kotlin DSL):
dependencies {
implementation(platform("st.orm:storm-bom:@@STORM_VERSION@@"))
}plugins {
id("com.google.devtools.ksp") version "2.0.21-1.0.28"
}
dependencies {
implementation(platform("st.orm:storm-bom:@@STORM_VERSION@@"))
implementation("st.orm:storm-kotlin")
runtimeOnly("st.orm:storm-core")
ksp("st.orm:storm-metamodel-ksp")
kotlinCompilerPluginClasspath("st.orm:storm-compiler-plugin-2.0")
}The storm-metamodel-ksp dependency generates type-safe metamodel classes (e.g., User_, City_) at compile time. See Metamodel for details. The storm-compiler-plugin automatically wraps string interpolations inside SQL template lambdas, making queries injection-safe by default. The 2.0 suffix matches the Kotlin major.minor version used in your project (e.g., storm-compiler-plugin-2.1 for Kotlin 2.1.x). See String Templates for details.
Gradle (Kotlin DSL):
dependencies {
implementation(platform("st.orm:storm-bom:@@STORM_VERSION@@"))
implementation("st.orm:storm-java21")
runtimeOnly("st.orm:storm-core")
annotationProcessor("st.orm:storm-metamodel-processor")
}
tasks.withType<JavaCompile> {
options.compilerArgs.add("--enable-preview")
}
tasks.withType<Test> {
jvmArgs("--enable-preview")
}Maven:
<dependencies>
<dependency>
<groupId>st.orm</groupId>
<artifactId>storm-java21</artifactId>
</dependency>
<dependency>
<groupId>st.orm</groupId>
<artifactId>storm-core</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>st.orm</groupId>
<artifactId>storm-metamodel-processor</artifactId>
<scope>provided</scope>
</dependency>
</dependencies>Enable preview features for String Templates (JEP 430):
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<release>21</release>
<compilerArgs>
<arg>--enable-preview</arg>
</compilerArgs>
</configuration>
</plugin>The metamodel processor generates type-safe metamodel classes (e.g., User_, City_) at compile time. See Metamodel for details.
Storm is modular. Add only what you need.
Storm works with any JDBC-compatible database out of the box. Dialect modules provide database-specific optimizations (e.g., native upsert syntax, tuple comparisons). Add the one that matches your database as a runtime dependency:
| Module | Database |
|---|---|
storm-oracle |
Oracle |
storm-mssqlserver |
SQL Server |
storm-postgresql |
PostgreSQL |
storm-mysql |
MySQL |
storm-mariadb |
MariaDB |
storm-sqlite |
SQLite |
storm-h2 |
H2 |
runtimeOnly("st.orm:storm-postgresql")See Database Dialects for what each dialect provides.
For Spring Boot applications, use the starter modules instead of the base modules. The starters auto-configure the ORMTemplate bean, enable repository scanning, and integrate with Spring's transaction management. See Spring Integration for full setup details.
implementation("st.orm:storm-kotlin-spring-boot-starter")<dependency>
<groupId>st.orm</groupId>
<artifactId>storm-spring-boot-starter</artifactId>
</dependency>For Ktor applications, add the Ktor plugin module. It provides a Storm plugin that manages the DataSource lifecycle, reads HOCON configuration, and exposes the ORMTemplate through extension properties on Application, ApplicationCall, and RoutingContext. See Ktor Integration for full setup details.
implementation("st.orm:storm-ktor")For testing:
testImplementation("st.orm:storm-ktor-test")Storm supports storing and reading JSON-typed columns. Pick the module that matches your serialization library:
| Module | Library |
|---|---|
storm-jackson2 |
Jackson 2.17+ (Spring Boot 3.x) |
storm-jackson3 |
Jackson 3.0+ (Spring Boot 4+) |
storm-kotlinx-serialization |
Kotlinx Serialization |
See JSON Support for usage details.
| Module | Provides |
|---|---|
storm-micrometer |
Micrometer Observations for queries and transactions (storm.query, storm.transaction), the OpenTelemetry database semantic conventions, and trace-context SQL comments |
The Spring Boot starters include storm-micrometer; Ktor applications add it explicitly. See the observability sections of Spring Integration and Ktor Integration.
| Module | Provides |
|---|---|
storm-test |
@StormTest JUnit 5 extension and SqlCapture, framework-free |
storm-spring-boot-test-autoconfigure |
The @DataStormTest Spring Boot test slice (test scope) |
See Testing and Testing with @DataStormTest.
The following diagram shows how Storm's modules relate to each other. You only need the modules relevant to your language and integration choices.
storm-foundation (base interfaces)
└── storm-kotlin / storm-java21 (your primary dependency)
├── storm-kotlin-spring / storm-spring (Spring Framework)
│ └── storm-kotlin-spring-boot-starter / storm-spring-boot-starter
├── storm-ktor (Ktor)
│ └── storm-ktor-test (testing support)
├── dialect modules (postgresql, mysql, mariadb, oracle, mssqlserver, sqlite, h2)
└── JSON modules (jackson2, jackson3, kotlinx-serialization)
With Storm installed, you are ready to define your first entity and run your first query:
- First Entity -- define an entity, create an ORM template, insert and fetch a record
- First Query -- custom queries, repositories, and type-safe filtering