Example usage for java.util.stream StreamSupport stream

Introduction

In this page you can find the example usage for java.util.stream StreamSupport stream.

Prototype

public static <T> Stream<T> stream(Supplier<? extends Spliterator<T>> supplier, int characteristics,
        boolean parallel) 

Source Link

Document

Creates a new sequential or parallel Stream from a Supplier of Spliterator .

Usage

From source file:org.nuxeo.ecm.core.storage.marklogic.MarkLogicRepository.java

protected Stream<State> findAll(String ctsQuery, String... selects) {
    String query = ctsQuery;//w  ww.  ja va2  s . co  m
    if (selects.length > 0) {
        query = "import module namespace extract = 'http://nuxeo.com/extract' at '/ext/nuxeo/extract.xqy';\n"
                + "let $paths := ("
                + Arrays.stream(selects).map(MarkLogicHelper::serializeKey)
                        .map(select -> "\"" + MarkLogicHelper.DOCUMENT_ROOT_PATH + "/" + select + "\"")
                        .collect(Collectors.joining(",\n"))
                + ")let $namespaces := ()\n" + "for $i in " + query
                + " return extract:extract-nodes($i, $paths, $namespaces)";
    }
    if (log.isTraceEnabled()) {
        logQuery(query);
    }
    // Run query
    boolean completedAbruptly = true;
    Session session = xccContentSource.newSession();
    try {
        // As we can get a lot of results don't buffer the result
        RequestOptions options = new RequestOptions();
        options.setCacheResult(false);
        AdhocQuery request = session.newAdhocQuery(query, options);

        // We give 0 as characteristics because it's the value used by Iterable#spliterator() and according to
        // StreamSupport.stream(Supplier, int, boolean) documentation, characteristics must be equal to
        // supplier.get().characteristics()
        Supplier<Spliterator<ResultItem>> spliteratorSupplier = () -> {
            try {
                // ResultSequence will be closed by Session close (closed by stream closed)
                ResultSequence rs = session.submitRequest(request);
                Iterable<ResultItem> items = rs::iterator;
                return items.spliterator();
            } catch (RequestException e) {
                throw new NuxeoException("An exception happened during xcc call", e);
            }
        };
        Stream<State> stream = StreamSupport.stream(spliteratorSupplier, 0, false).onClose(session::close)
                .map(ResultItem::getItem).map(XdmItem::asInputStream)
                .map(MarkLogicStateDeserializer::deserialize);
        // the stream takes responsibility for closing the session
        completedAbruptly = false;
        return stream;
    } finally {
        if (completedAbruptly) {
            session.close();
        }
    }
}

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