Gradle Dependency Resolution

Normal Gradle behavior

The default behavior of Gradle to pick the newest version also applies if a lower version has been declared locally, but another dependency transitively pulls in a newer version. This is in contrast with Maven, where a locally declared version will always win.

For example, if your build.gradle specifies the dependency org.springframework:spring-tx:3.2.3.RELEASE, and another dependency declares 4.0.5.RELEASE as a transitive dependency, then 4.0.5.RELEASE will take precedence:

dependencies {
    compile("org.springframework.data:spring-data-hadoop:2.0.0.RELEASE")
    compile("org.springframework:spring-tx:3.2.3.RELEASE")
    // will select org.springframework:spring-tx:4.0.5.RELEASE
}

Forcing specific versions

Using `ResolutionStrategy.force(Object...)`:

One option to force Gradle to use the specified version, thus obtaining a behavior similar to Maven, is to use ResolutionStrategy.force(Object...):

configurations.all {
    resolutionStrategy {
        force "org.springframework:spring-tx:3.2.3.RELEASE"
    }
}

When there are multiple conflicting ResolutionStrategy.force calls, the last one to be executed wins:

configurations.all {
    resolutionStrategy {
        force "org.springframework:spring-tx:3.2.5.RELEASE"
        force "org.springframework:spring-tx:3.2.7.RELEASE"
        force "org.springframework:spring-tx:3.2.6.RELEASE"
        // will select org.springframework:spring-tx:3.2.6.RELEASE (the last one)
    }
}

Interestingly, force is implemented as a conflict resolution strategy, too (see ModuleForcingResolveRule and DefaultResolutionStrategy). It is executed before the other resolution strategies.

Using `ExternalDependency.force`:

The other option is to use force on the dependency itself:

dependencies {
    compile("org.springframework.data:spring-data-hadoop:2.0.0.RELEASE")
    compile("org.springframework:spring-tx:3.2.3.RELEASE") {
        force = true
    }
}

This is perhaps the option that is most similar to Maven.

Note that if both ResolutionStrategy.force and ExternalDependency.force are used, the former takes precedence over the latter.

petarov/README.md