Generate Code

Code Generation

Similar to JPA2.0 Criteria, QueryDsl, Fluent MyBatis, etc., Jimmer uses strongly typed DSLs to catch errors at compile-time rather than runtime.

So some additional code needs to be generated at compile-time based on user-defined entities:

• Java users use Annotation Processor
• Kotlin users use KSP

Java (Maven)

pom.xml

...other code omitted... 

<build>
  <plugins>
    <plugin>
      <groupId>org.apache.maven.plugins</groupId>
      <artifactId>maven-compiler-plugin</artifactId>
      <version>3.10.1</version>
      <configuration>
        <annotationProcessorPaths>
          <path>
            <groupId>org.babyfish.jimmer</groupId>
            <artifactId>jimmer-apt</artifactId>
            <version>${jimmer.version}</version>
          </path>
        </annotationProcessorPaths>
      </configuration>
    </plugin>
  </plugins>
</build>

...other code omitted...

Java (Gradle)

dependencies {

  ...other dependencies omitted...

  annotationProcessor "org.babyfish.jimmer:jimmer-apt:${jimmerVersion}" 
}

Kotlin (Gradle.kts)

plugins {
  // Add KSP plugin  
  id("com.google.devtools.ksp") version "1.7.10-1.0.6"

  ...other plugins omitted...
}

dependencies {

  // Apply Jimmer's KSP code generator 
  ksp("org.babyfish.jimmer:jimmer-ksp:${jimmerVersion}")

  ...other dependencies omitted...
}

// Add generated code to compile path.
// Gradle build works without this, but IntelliJ won't find generated code. 
kotlin {
  sourceSets.main {
    kotlin.srcDir("build/generated/ksp/main/kotlin") 
  }
}

Java (Gradle Plugin)

build.gradle

plugins {
    // Starting from Gradle 7.0, you can use "latest.release" instead of a specific version number to represent the use of the latest version.
    // You can also use the '+' character to indicate matching the latest version number starting from the '+' character.
    id "tech.argonariod.gradle-plugin-jimmer" version "latest.release"

    ...other plugins omitted...
}

jimmer {
    // Set the Jimmer dependency version, where you can also use version range expressions such as "latest.release" or "0.+"
    version = "${jimmerVersion}"
}

Kotlin (Gradle Plugin)

build.gradle.kts

plugins {
    // Starting from Gradle 7.0, you can use "latest.release" instead of a specific version number to represent the use of the latest version.
    id("tech.argonariod.gradle-plugin-jimmer") version "latest.release"
    // You can also use the '+' character to indicate matching the latest version number starting from the '+' character.
    // Add KSP plugin
    id("com.google.devtools.ksp") version "1.7.10+"

    ...other plugins omitted...
}

jimmer {
    // Set the Jimmer dependency version, where you can also use version range expressions such as "latest.release" or "0.+"
    version = "${jimmerVersion}"
}

info

• The first three: Standard configurations
• The last two: Community-provided Gradle plugin for further simplifying configurations

note

KSP only supports gradle, It has been proven that KSP's third-party Maven plug-in support cannot keep up with the version iteration of 'kotlin/KSP' itself, and often encounters many problems during the upgrade process.

Eventually, Jimmer dropped Maven support for Kotlin and asked Kotlin developers to use Gradle.

After this configuration, running Maven or Gradle will generate additional source code based on user-defined entities.

caution

The above only applies to simple projects without separation.

For real projects with separate entity definition, generator (annotation processor/ksp) must be configured in the project that defines entity types.

Jimmer data types require one of:

• @Immutable
• @Entity
• @MappedSuperclass
• @Embeddable

The first is ORM-agnostic, the others are ORM-related.

If entities use the ORM annotations (eg: @Entity), the generated code requires jimmer-sql while entity code ifself only needs jimmer-core:

Maven

pom.xml

...other code omitted...

<dependencies>

  <!-- User entity code -->
  <dependency>
    <groupId>org.babyfish.jimmer</groupId>
    <artifactId>jimmer-core</artifactId>
    <version>${jimmer.version}</version>
  </dependency>

  <!-- Generated code --> 
  <dependency>
    <groupId>org.babyfish.jimmer</groupId>
    <artifactId>jimmer-sql</artifactId>
    <version>${jimmer.version}</version>
    <!-- Imported by other projects -->
    <scope>provided</scope>
  </dependency>

  ...other dependencies omitted...  
</dependencies>

...other code omitted...

Java (Gradle Plugin)

build.gradle

jimmer {
    // Ensure that jimmer-sql is only depended upon during code generation and compilation.
    ormCompileOnly = true

    ...other configurations omitted...
}

...other code omitted...

Kotlin (Gradle Plugin)

build.gradle.kts

jimmer {
    // Ensure that jimmer-sql-kotlin is only depended upon during code generation and compilation.
    ormCompileOnly = true

    ...other configurations omitted...
}

...other code omitted...

Java (Gradle)

...other code omitted...

dependencies {

  ...other dependencies omitted...

  // User entity code
  implementation "org.babyfish.jimmer:jimmer-core:${jimmerVersion}"

  // Generated code  
  compileOnly "org.babyfish.jimmer:jimmer-sql:${jimmerVersion}"
}

...other code omitted...

Kotlin (Gradle.kts)

...other code omitted... 

dependencies {

  ...other dependencies omitted...

  // User entity code
  implementation("org.babyfish.jimmer:jimmer-core:${jimmerVersion}")

  // Generated code
  compileOnly("org.babyfish.jimmer:jimmer-sql:${jimmerVersion}") 
}

...other code omitted...

Verify Successful Generation

If generation succeeded, developers should see:

Java	Kotlin

note

Screenshots are from Gradle project.

For Maven, top level directory is target instead of build.

caution

Normally IDE marks generated code directories with icon.

But sometimes IntelliJ fails to do so, preventing use of generated code.

In this case, right-click on directory, choose Mark Directory As -> Generated Sources Root.

Generated code includes:

Java	Kotlin	Description
XXXDraft.java	XXXDraft.kt	Mutable proxy interface for immutable object, object implementation, and methods to create and "modify" objects
XXXProps.java	XXXProps.kt	Typed SQL DSL
XXXTable.java
XXXTableEx.java
XXXFetcher.java	XXXFetcher.kt	Object fetcher DSL defining shape of complex query results