ServiceTalk Examples

These examples are meant to demonstrate Gradle and Maven build file configuration outside the ServiceTalk project. For a full set of examples see the ServiceTalk Repo.

This project uses Gradle to build and also includes a Maven pom.xml in the gRPC helloworld example to demo how the ServiceTalk gRPC code generation Maven integration works.

ServiceTalk BOM

The example Gradle build.gradle and Maven pom.xml include use of BOM (Bill of Materials) pom and module files. BOM files allow separation of dependency management and version management; a BOM specifies only component versions, not dependencies. Centralizing the management of versions to a single file greatly reduces the maintenance burden for updating to new versions and improves consistency because all references to a dependency will use the same version. The BOM files define the versions of modules which might be included as dependencies, but do not include the module as a dependency. Later when the module is included as a dependency, the dependency is specified without including a version and the version specified in the BOM is used.

ServiceTalk includes two BOM files each with slightly different purposes:

• The servicetalk-bom BOM includes version information for all ServiceTalk modules; version selection for external non-ServiceTalk dependencies is done in individual modules.
• The servicetalk-dependencies BOM extends the servicetalk-bom by also defining specific versions to be used for ServiceTalk's external dependencies.

The servicetalk-dependencies BOM should be preferred whenever possible. Unless your application requires different versions of these same dependencies then using the servicetalk-dependencies BOM is the most convenient way to ensure that a tested and supported set of modules is used or building and running the application. Using the servicetalk-bom may be easier when your application wishes to do more complete management of external dependencies, or you wish to include ServiceTalk as an enforcedPlatform, but do not want the external dependencies to be included in that constraint.

To override the version of a specific dependency with your application's required version you can use something like the following in your build.gradle:

implementation(platform("io.servicetalk:servicetalk-dependencies:$servicetalkVersion"))

// Overrides the default Netty BOM version imported by ServiceTalk with a specific version
implementation(enforcedPlatform("io.netty:netty-bom")) {
    version {
        strictly '4.1.76.Final'
    }
}
// Overrides the default Jackson databind module version with a specific version
implementation ("com.fasterxml.jackson.core:jackson-databind") {
    version {
        strictly '2.13.3'
    }
}