Resolving Dependencies

Extending the code snippets from Creating a RepositorySystemSession, the snippet below demonstrates how to actually resolve the transitive dependencies of say org.apache.maven:maven-core:3.9.6 and to dump the result as a class path to the console:

    public static void main( String[] args )
        throws Exception
    {
        RepositorySystem repoSystem = newRepositorySystem();

        RepositorySystemSession session = newSession( repoSystem );

        Dependency dependency =
            new Dependency( new DefaultArtifact( "org.apache.maven:maven-core:3.9.6" ), "compile" );
        RemoteRepository central = new RemoteRepository.Builder( "central", "default", "https://repo.maven.apache.org/maven2/" ).build();

        CollectRequest collectRequest = new CollectRequest();
        collectRequest.setRoot( dependency );
        collectRequest.addRepository( central );
        DependencyNode node = repoSystem.collectDependencies( session, collectRequest ).getRoot();

        DependencyRequest dependencyRequest = new DependencyRequest();
        dependencyRequest.setRoot( node );

        repoSystem.resolveDependencies( session, dependencyRequest  );

        PreorderNodeListGenerator nlg = new PreorderNodeListGenerator();
        node.accept( nlg );
        System.out.println( nlg.getClassPath() );
    }

So once you have initialized the repository system and created a session, the general pattern is to create some request object, call its setters to configure the request, do the operation and evaluate the result object.

Since “all theory is grey”, we maintain some runnable examples and demos among our sources. These examples provide a more extensive demonstration of Resolver and its use, so what are you waiting for?