Java 类com.hp.hpl.jena.query.ResultSetRewindable 实例源码

/**
 * Positive test.
 */
@Test
public void range() {
    final int offset = 120; 
    final int size = 24;

    final ResultSetRewindable cut = new PagedResultSet(executeQuery(), size, offset);
    final ResultSet resultSet = executeQuery();

    while (cut.hasNext()) {
        cut.next();
    }

    assertEquals(size, cut.size());
    cut.reset();

    for (int i = 0; i < offset; i++) {
        resultSet.next();
    }

    for (int i = 0; i < size; i++) {
        assertEquals(resultSet.nextBinding(), cut.nextBinding());
    }

    assertFalse(cut.hasNext());
}

@PostConstruct
public void constructor() {

    // create the dataset for the copy of vivo
    String vivoDirectory = "/resources/jena/vivo";

    String realVivoDirectory = context.getRealPath(vivoDirectory);
    logger.info("The vivo dataset is stored in " + realVivoDirectory);

    this.ds = TDBFactory.createDataset(realVivoDirectory);
    this.m = ds.getDefaultModel();

    this.cache = new HashMap<Integer, ResultSetRewindable>();
}

/**
 * If the required size (+offset) is greater than the underlying resultset size then only the available rows will be returned. 
 */
@Test
public void sizeGreaterThanEffectiveSize() {
    final ResultSetRewindable cut = new PagedResultSet(executeQuery(), 10, (int)(model.size() - 5));

    while (cut.hasNext()) {
        cut.next();
    }

    assertEquals(5, cut.size());
    cut.reset();
}

/**
 * In case the required size + offset denotes an unavailable set of results, then an exception will be thrown.
 */
@Test
public void outOfAvailableRange() {
    final ResultSetRewindable cut = new PagedResultSet(executeQuery(), 10, (int)(model.size() + 1));

    while (cut.hasNext()) {
        cut.next();
    }

    assertEquals(0, cut.size());

    cut.reset();

    assertEquals(0, cut.size());
}

/**
 * With a size equals to 0, the {@link PagedResultSet} will be empty, 
 * but at least one iteration step needs to be done on the wrapped {@link ResultSet}.
 */
@Test
public void zeroSize() {
    final ResultSet rs = mock(ResultSet.class);
    when(rs.hasNext()).thenReturn(true);

    final ResultSetRewindable cut = new PagedResultSet(rs, 0, 10);

    verify(rs).next();

    assertFalse(cut.hasNext());
}

private QueryInfo query(String epURL, String operation) {
    QueryInfo info = new QueryInfo();
    info.setURL(epURL);
    info.setOperation(operation);

    String queryString = query.replaceAll("%%s", "<"+_ep.getUri()+">");

    HashSet<String> voidAset= new HashSet<String>();

    ArrayList<CharSequence> voidA = new ArrayList<CharSequence>();
    info.setResults(voidA);

    // initializing queryExecution factory with remote service.
    QueryExecution qexec = null;
    try {
        qexec = QueryManager.getExecution(epURL, queryString);

        boolean results = false;

        ResultSet resSet = qexec.execSelect();
        ResultSetRewindable reswind = ResultSetFactory.makeRewindable(resSet);

        while(reswind.hasNext()){
            RDFNode dataset = reswind.next().get("ds");
            voidAset.add(dataset.toString());
        }

        voidA.addAll(voidAset);
        log.info("Found {} results",reswind.getRowNumber());
    } catch (Exception e1) {
        info.setException(ExceptionHandler.logAndtoString(e1));
        log.debug("[EXEC] SPARQL query to "+epURL+" for "+_epURI, e1);
    }
    finally {
        if(qexec!=null)qexec.close();
    }
    return info;

}

public SelectionResult runSelectionQuery(Op op) {

        SelectionResult result = new SelectionResult();

        ResultSetRewindable results = jenaService.runExternalOp(op);

        results.reset();

        for (; results.hasNext();) {
            QuerySolution soln = results.next();

            RDFNode predicate = soln.get("predicate");
            RDFNode object = soln.get("value");

            Literal literal = object.asLiteral();
            if (!literal.getString().isEmpty()) {
                result.addResult(predicate, literal);
            }
        }

        return result;
    }

public ResultSetRewindable runLocalOp(Op op) {
    long startTime = System.currentTimeMillis();
    Query q = OpAsQuery.asQuery(op);
    logger.debug("Running query on the local dataset" + ":"
    // + "\n\nORIGINAL OP:\n"
    // + op.toString()
    // + "\n\nOPTIMIZED OP\n"
    // + Algebra.optimize(op)
            + "\n\nSPARQL QUERY\n" + q.toString(Syntax.syntaxARQ));

    try {
        Integer key = op.toString().hashCode();
        if (cache.containsKey(key)) {
            logger.debug("The query was cached.");
            return cache.get(key);
        }

        ds.begin(ReadWrite.READ);

        QueryIterator qIter = Algebra.exec(op, this.ds);

        List<String> vars = new LinkedList<String>();
        for (Var var : OpAsQuery.asQuery(op).getProjectVars()) {
            vars.add(var.getVarName());
        }

        ResultSetRewindable results = ResultSetFactory
                .copyResults(ResultSetFactory.create(qIter, vars));

        long endTime = System.currentTimeMillis();
        String timeString = new SimpleDateFormat("mm:ss:SSS")
                .format(new Date(endTime - startTime));

        // cache disabled
        // cache.put(op.toString().hashCode(), results);

        logger.info("The query returned after " + timeString + " with "
                + results.size() + " results");
        return results;
    } finally {
        ds.end();
    }
}

public ResultSetRewindable runExternalOp(Op op) {

        long startTime = System.currentTimeMillis();

        Query q = OpAsQuery.asQuery(op);
        logger.info("Running query on the external dataset:\n\n"
                + "SPARQL QUERY\n" + q.toString(Syntax.syntaxARQ));

        QueryExecution qexec = QueryExecutionFactory.sparqlService(
                Constants.getSparqlService(), q);

        ResultSetRewindable results = ResultSetFactory.copyResults(qexec
                .execSelect());

        long endTime = System.currentTimeMillis();
        String timeString = new SimpleDateFormat("mm:ss:SSS").format(new Date(
                endTime - startTime));

        logger.info("The query returned after " + timeString + " with "
                + results.size() + " results");

        qexec.close();

        return results;
    }

/**
 * In case the decorated {@link ResultSet} is null then an empty wrapper will be returned.
 */
@Test
public void nullResultSet() {
    final ResultSetRewindable cut = new PagedResultSet(null, 10, 0);
    assertFalse(cut.hasNext());
}