import org.eclipse.aether.util.graph.selector.ScopeDependencySelector; //导入依赖的package包/类
/**
 * Set up repository session for maven.
 * 
 * @param system
 *          the repository system
 * @param localDownloadDir
 *          the directory where to put the downloaded artifacts
 * @return the configured repository session
 */
private RepositorySystemSession newSession(RepositorySystem system, final String localDownloadDir) {
  DefaultRepositorySystemSession session = MavenRepositorySystemUtils.newSession();

  LocalRepository localRepo = new LocalRepository(localDownloadDir);
  session.setLocalRepositoryManager(system.newLocalRepositoryManager(session, localRepo));

  DependencySelector depFilter =
      new AndDependencySelector(
      new ScopeDependencySelector(JavaScopes.PROVIDED),
      new OptionalDependencySelector(),
      new ExclusionDependencySelector()
  );
  session.setDependencySelector(depFilter);

  return session;
}
 

import org.eclipse.aether.util.graph.selector.ScopeDependencySelector; //导入依赖的package包/类
private Page<Artifact, Artifact> fetch(Artifact artifact)
		throws SettingsBuildingException, DependencyResolutionException, DependencyCollectionException {
	ScopeDependencySelector dependencySelector = new ScopeDependencySelector(
			Collections.singleton(JavaScopes.COMPILE), Collections.emptySet());
	Dependency task = new Dependency(new Maven());
	Processor processor = new Processor(task, true, true, JavaScopes.COMPILE, dependencySelector, false);
	return processor.process(artifact);
}
 

import org.eclipse.aether.util.graph.selector.ScopeDependencySelector; //导入依赖的package包/类
@Before
public void before() throws SettingsBuildingException {
	this.artifact = new DefaultArtifact("org.neo4j", "neo4j", "jar", "3.0.5");
	this.fetcher = new Dependency(new Maven());
	this.dependencySelector = new ScopeDependencySelector(Collections.singleton(JavaScopes.COMPILE),
			Collections.emptySet());
}
 

import org.eclipse.aether.util.graph.selector.ScopeDependencySelector; //导入依赖的package包/类
@Bean(PACKAGE + ".processorFactory")
public Supplier<Processor> processorFactory() throws SettingsBuildingException {
	Maven maven = new Maven();
	return () -> new Processor(new Dependency(maven), this.catchDependencyCollectionException,
			this.catchDependencyResolutionException, this.scope,
			new ScopeDependencySelector(this.excludedDependencySelectorScopes), this.includeUnresolved);
}
 

import org.eclipse.aether.util.graph.selector.ScopeDependencySelector; //导入依赖的package包/类
public RepositoryContext ( final Path tmpDir, final String repositoryUrl, final Boolean allOptional )
{
    this.system = Helper.newRepositorySystem ();
    this.session = Helper.newRepositorySystemSession ( tmpDir, this.system );

    if ( allOptional != null )
    {
        final List<DependencySelector> selectors = new LinkedList<> ();

        selectors.add ( new ScopeDependencySelector ( "test", "provided" ) );
        if ( !allOptional )
        {
            selectors.add ( new OptionalDependencySelector () );
        }
        selectors.add ( new ExclusionDependencySelector () );
        this.session.setDependencySelector ( new AndDependencySelector ( selectors ) );
    }

    if ( repositoryUrl == null || repositoryUrl.isEmpty () )
    {
        this.repositories = Collections.singletonList ( Helper.newCentralRepository () );
    }
    else
    {
        this.repositories = Collections.singletonList ( Helper.newRemoteRepository ( "drone.aether.import", repositoryUrl ) );
    }
}
 

import org.eclipse.aether.util.graph.selector.ScopeDependencySelector; //导入依赖的package包/类
@Bean
public RepositorySystemSession repositorySystemSession(RepositorySystem repositorySystem) {
    // see MavenRepositorySystemUtils.newSession()

    DependencySelector selector = new AndDependencySelector(
            new ScopeDependencySelector("test", "provided"),
            new DepthOneOptionalDependencySelector(),
            new ExclusionDependencySelector());

    DependencyGraphTransformer transformer = new ConflictResolver(
            new NearestVersionSelector(),
            new JavaScopeSelector(),
            new SimpleOptionalitySelector(),
            new JavaScopeDeriver());

    DefaultRepositorySystemSession session = new DefaultRepositorySystemSession();
    session.setLocalRepositoryManager(repositorySystem.newLocalRepositoryManager(session, localRepository()));
    session.setSystemProperties(System.getProperties());
    session.setConfigProperties(System.getProperties());
    session.setArtifactTypeRegistry(artifactTypeRegistry());
    session.setDependencyManager(new ClassicDependencyManager());
    session.setArtifactDescriptorPolicy(new SimpleArtifactDescriptorPolicy(true, true));
    session.setDependencySelector(selector);
    session.setDependencyGraphTransformer(transformer);
    session.setTransferListener(new LogTransferListener());
    session.setRepositoryListener(new LogRepositoryListener());

    if (!session.getConfigProperties().containsKey(ConfigurationProperties.REQUEST_TIMEOUT)) {
        session.setConfigProperty(ConfigurationProperties.REQUEST_TIMEOUT, 3 * 60 * 1000);
    }

    return session;
}