simba-spring-boot-starter Module

The simba-spring-boot-starter module provides Spring Boot auto-configuration for all three Simba backends (JDBC, Redis, Zookeeper). It uses conditional annotations and Gradle feature variants so that only the selected backend's dependencies are pulled into the application.

Auto-Configuration Classes

The module registers three auto-configuration classes via Spring Boot's standard mechanism.

Source: simba-spring-boot-starter/.../org.springframework.boot.autoconfigure.AutoConfiguration.imports

me.ahoo.simba.spring.boot.starter.jdbc.SimbaJdbcAutoConfiguration
me.ahoo.simba.spring.boot.starter.redis.SimbaSpringRedisAutoConfiguration
me.ahoo.simba.spring.boot.starter.zookeeper.SimbaZookeeperAutoConfiguration

Configuration Flow

graph TD
    subgraph sg_41 ["Application Startup"]

        APP["SpringApplication"]
    end
    subgraph sg_42 ["Conditional Evaluation"]

        CE1["simba.enabled = true?"]
        CE2["simba.jdbc.enabled = true?<br>+ JdbcMutexContendServiceFactory on classpath?<br>+ DataSource bean exists?"]
        CE3["simba.redis.enabled = true?<br>+ StringRedisTemplate on classpath?<br>+ RedisConnectionFactory exists?"]
        CE4["simba.zookeeper.enabled = true?<br>+ ZookeeperMutexContendServiceFactory on classpath?<br>+ CuratorFramework bean exists?"]
    end
    subgraph sg_43 ["Beans Registered"]

        B1["MutexOwnerRepository<br>JdbcMutexContendServiceFactory"]
        B2["RedisMessageListenerContainer<br>SpringRedisMutexContendServiceFactory"]
        B3["ZookeeperMutexContendServiceFactory"]
    end

    APP --> CE1
    CE1 -->|"true"| CE2
    CE1 -->|"true"| CE3
    CE1 -->|"true"| CE4
    CE1 -->|"false"| NONE["No Simba beans"]

    CE2 -->|"all match"| B1
    CE3 -->|"all match"| B2
    CE4 -->|"all match"| B3

    style APP fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style CE1 fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style CE2 fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style CE3 fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style CE4 fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style B1 fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style B2 fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style B3 fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style NONE fill:#2d333b,stroke:#6d5dfc,color:#e6edf3

Conditional Annotations

The module uses a two-level conditional annotation hierarchy:

graph TD
    subgraph sg_44 ["Annotation Hierarchy"]

        CSE["@ConditionalOnSimbaEnabled<br>simba.enabled = true"]
        CJDBC["@ConditionalOnSimbaJdbcEnabled<br>@ConditionalOnSimbaEnabled<br>+ simba.jdbc.enabled = true"]
        CREDIS["@ConditionalOnSimbaRedisEnabled<br>@ConditionalOnSimbaEnabled<br>+ simba.redis.enabled = true"]
        CZK["@ConditionalOnSimbaZookeeperEnabled<br>@ConditionalOnSimbaEnabled<br>+ simba.zookeeper.enabled = true"]
    end

    CJDBC --> CSE
    CREDIS --> CSE
    CZK --> CSE

    style CSE fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style CJDBC fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style CREDIS fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style CZK fill:#2d333b,stroke:#6d5dfc,color:#e6edf3

ConditionalOnSimbaEnabled

Source: simba-spring-boot-starter/.../ConditionalOnSimbaEnabled.kt:23

@ConditionalOnProperty(
    value = ["simba.enabled"],
    matchIfMissing = true,
    havingValue = "true"
)
annotation class ConditionalOnSimbaEnabled

Global switch. Defaults to true when the property is not set.

ConditionalOnSimbaJdbcEnabled

Source: simba-spring-boot-starter/.../ConditionalOnSimbaJdbcEnabled.kt:24

@ConditionalOnSimbaEnabled
@ConditionalOnProperty(
    value = ["simba.jdbc.enabled"],
    matchIfMissing = true,
    havingValue = "true"
)
annotation class ConditionalOnSimbaJdbcEnabled

ConditionalOnSimbaRedisEnabled

Source: simba-spring-boot-starter/.../ConditionalOnSimbaRedisEnabled.kt:28

@ConditionalOnSimbaEnabled
@ConditionalOnProperty(
    value = ["simba.redis.enabled"],
    matchIfMissing = true,
    havingValue = "true"
)
annotation class ConditionalOnSimbaRedisEnabled

ConditionalOnSimbaZookeeperEnabled

Source: simba-spring-boot-starter/.../ConditionalOnSimbaZookeeperEnabled.kt:26

@ConditionalOnSimbaEnabled
@ConditionalOnProperty(
    value = ["simba.zookeeper.enabled"],
    matchIfMissing = true,
    havingValue = "true"
)
annotation class ConditionalOnSimbaZookeeperEnabled

Auto-Configuration Details

SimbaJdbcAutoConfiguration

Source: simba-spring-boot-starter/.../SimbaJdbcAutoConfiguration.kt:32

@AutoConfiguration
@ConditionalOnSimbaJdbcEnabled
@ConditionalOnClass(JdbcMutexContendServiceFactory::class)
@EnableConfigurationProperties(JdbcProperties::class)
class SimbaJdbcAutoConfiguration(private val jdbcProperties: JdbcProperties) {

    @Bean @ConditionalOnMissingBean
    fun mutexOwnerRepository(dataSource: DataSource): MutexOwnerRepository

    @Bean @ConditionalOnMissingBean
    fun jdbcMutexContendServiceFactory(mutexOwnerRepository: MutexOwnerRepository): MutexContendServiceFactory
}

Condition	Bean
simba.jdbc.enabled = true + JdbcMutexContendServiceFactory on classpath + DataSource bean exists	MutexOwnerRepository
Same as above + MutexOwnerRepository bean exists	MutexContendServiceFactory (as JdbcMutexContendServiceFactory)

SimbaSpringRedisAutoConfiguration

Source: simba-spring-boot-starter/.../SimbaSpringRedisAutoConfiguration.kt:34

@AutoConfiguration(after = [DataRedisAutoConfiguration::class])
@ConditionalOnSimbaRedisEnabled
@ConditionalOnClass(StringRedisTemplate::class)
@EnableConfigurationProperties(RedisProperties::class)
class SimbaSpringRedisAutoConfiguration(private val redisProperties: RedisProperties) {

    @Bean @ConditionalOnMissingBean @ConditionalOnSingleCandidate(RedisConnectionFactory::class)
    fun simbaRedisMessageListenerContainer(connectionFactory: RedisConnectionFactory): RedisMessageListenerContainer

    @Bean @ConditionalOnMissingBean @ConditionalOnBean(StringRedisTemplate::class)
    fun redisMutexContendServiceFactory(
        redisTemplate: StringRedisTemplate,
        listenerContainer: RedisMessageListenerContainer
    ): MutexContendServiceFactory
}

Condition	Bean
simba.redis.enabled = true + StringRedisTemplate on classpath + RedisConnectionFactory exists	RedisMessageListenerContainer
Same as above + StringRedisTemplate bean exists	MutexContendServiceFactory (as SpringRedisMutexContendServiceFactory)

The configuration runs after = DataRedisAutoConfiguration to ensure the Redis infrastructure beans are available.

SimbaZookeeperAutoConfiguration

Source: simba-spring-boot-starter/.../SimbaZookeeperAutoConfiguration.kt:30

@AutoConfiguration
@ConditionalOnSimbaZookeeperEnabled
@ConditionalOnClass(ZookeeperMutexContendServiceFactory::class)
@EnableConfigurationProperties(ZookeeperProperties::class)
class SimbaZookeeperAutoConfiguration {

    @Bean @ConditionalOnBean(CuratorFramework::class) @ConditionalOnMissingBean
    fun zookeeperMutexContendServiceFactory(curatorFramework: CuratorFramework): ZookeeperMutexContendServiceFactory
}

Condition	Bean
simba.zookeeper.enabled = true + ZookeeperMutexContendServiceFactory on classpath + CuratorFramework bean exists	MutexContendServiceFactory (as ZookeeperMutexContendServiceFactory)

Properties Binding

All properties are bound under the simba prefix.

Complete Properties Reference

simba:
  enabled: true                # Global switch (default: true)

  jdbc:
    enabled: true              # JDBC backend (default: true)
    initial-delay: 0s          # Delay before first contention
    ttl: 10s                   # Lock TTL
    transition: 6s             # Grace period

  redis:
    enabled: true              # Redis backend (default: true)
    ttl: 10s                   # Lock TTL
    transition: 6s             # Grace period

  zookeeper:
    enabled: true              # Zookeeper backend (default: true)

Property	Source Class	Default
simba.enabled	ConditionalOnSimbaEnabled	true
simba.jdbc.enabled	JdbcProperties	true
simba.jdbc.initial-delay	JdbcProperties	0s
simba.jdbc.ttl	JdbcProperties	10s
simba.jdbc.transition	JdbcProperties	6s
simba.redis.enabled	RedisProperties	true
simba.redis.ttl	RedisProperties	10s
simba.redis.transition	RedisProperties	6s
simba.zookeeper.enabled	ZookeeperProperties	true

Gradle Feature Variants

The starter uses Gradle's registerFeature to create optional capability variants. This ensures consumers only pull backend dependencies they need.

Source: simba-spring-boot-starter/build.gradle.kts:18

java {
    registerFeature("springRedisSupport") {
        usingSourceSet(sourceSets[SourceSet.MAIN_SOURCE_SET_NAME])
        capability(group.toString(), "spring-redis-support", version.toString())
    }
    registerFeature("jdbcSupport") {
        usingSourceSet(sourceSets[SourceSet.MAIN_SOURCE_SET_NAME])
        capability(group.toString(), "jdbc-support", version.toString())
    }
    registerFeature("zookeeperSupport") {
        usingSourceSet(sourceSets[SourceSet.MAIN_SOURCE_SET_NAME])
        capability(group.toString(), "zookeeper-support", version.toString())
    }
}

graph TD
    subgraph sg_45 ["Consumer Dependencies"]

        C1["Application A<br>requires spring-redis-support"]
        C2["Application B<br>requires jdbc-support"]
        C3["Application C<br>requires zookeeper-support"]
    end
    subgraph sg_46 ["simba-spring-boot-starter Features"]

        SR["springRedisSupport<br>-> simba-spring-redis<br>-> spring-boot-starter-data-redis"]
        JB["jdbcSupport<br>-> simba-jdbc"]
        ZK["zookeeperSupport<br>-> simba-zookeeper"]
    end
    subgraph sg_47 ["Always Included"]

        CORE["simba-core<br>spring-boot-starter"]
    end

    C1 -->|"capability"| SR
    C2 -->|"capability"| JB
    C3 -->|"capability"| ZK

    style C1 fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style C2 fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style C3 fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style SR fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style JB fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style ZK fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style CORE fill:#2d333b,stroke:#6d5dfc,color:#e6edf3

Consuming a Feature Variant

In the consuming application's build.gradle.kts:

dependencies {
    // Pull only the Redis backend
    implementation("me.ahoo.simba:simba-spring-boot-starter") {
        capabilities {
            requireCapability("me.ahoo.simba:spring-redis-support")
        }
    }
}

This pulls in simba-spring-redis and spring-boot-starter-data-redis, but NOT simba-jdbc or simba-zookeeper.

Enabled Suffix Convention

All backend enabled properties use the .enabled suffix constant:

Source: simba-spring-boot-starter/.../EnabledSuffix.kt:20

object EnabledSuffix {
    const val KEY = ".enabled"
}

Disabling Backends

Disable All of Simba

simba:
  enabled: false

Disable Specific Backends

simba:
  jdbc:
    enabled: false
  redis:
    enabled: false
  zookeeper:
    enabled: false

Enable Only One Backend

simba:
  jdbc:
    enabled: false
  redis:
    enabled: true
    ttl: 15s
    transition: 8s
  zookeeper:
    enabled: false

See Also

• simba-core Module -- core interfaces and abstract classes
• simba-jdbc -- JDBC backend details and properties
• simba-spring-redis -- Redis backend details and Lua scripts
• simba-zookeeper -- Zookeeper backend details