import org.openrdf.query.algebra.evaluation.TripleSource; //导入依赖的package包/类
/**
	 * Creates a new Evaluation strategy using the supplied source finder.
	 * 
	 * @param finder the source finder to use.
	 * @param vf the value factory to use.
	 */
	public FederationEvalStrategy(final ValueFactory vf) {
	
		// use a dummy triple source
		// it can handle only single triple patterns but no basic graph patterns
		super(new TripleSource() {
			@Override public ValueFactory getValueFactory() {
				return vf;
			}
//			@Override public Cursor<? extends Statement> getStatements(
//					Resource subj, URI pred, Value obj, Resource... contexts) throws StoreException {
			@Override public CloseableIteration<? extends Statement, QueryEvaluationException> getStatements(
					Resource subj, URI pred, Value obj, Resource... contexts) throws QueryEvaluationException {
				throw new UnsupportedOperationException("Statement retrieval is not supported in federation");
			}
		});
	}
 

import org.openrdf.query.algebra.evaluation.TripleSource; //导入依赖的package包/类
public KiWiEvaluationStrategy(TripleSource tripleSource, KiWiConnection connection, KiWiValueFactory valueFactory) {
    super(tripleSource);
    this.connection = connection;
    this.valueFactory = valueFactory;

    // interruptible queries run in a separate thread
    this.executorService = Executors.newCachedThreadPool();
}
 

import org.openrdf.query.algebra.evaluation.TripleSource; //导入依赖的package包/类
public RangeEvaluationStrategy(TripleSource tripleSource, Dataset dataset) {
	super(tripleSource, dataset);
}