Java Code Examples for org.hibernate.ScrollableResults#first()

@Test
public final void givenUsingTheScrollableApi_whenRetrievingPaginatedData_thenCorrect() {
    final int pageSize = 10;
    final String hql = "FROM Foo f order by f.name";
    final Query query = session.createQuery(hql);

    final ScrollableResults resultScroll = query.scroll(ScrollMode.FORWARD_ONLY);

    // resultScroll.last();
    // final int totalResults = resultScroll.getRowNumber() + 1;

    resultScroll.first();
    resultScroll.scroll(0);
    final List<Foo> fooPage = Lists.newArrayList();
    int i = 0;
    while (pageSize > i++) {
        fooPage.add((Foo) resultScroll.get(0));
        if (!resultScroll.next()) {
            break;
        }
    }

    assertThat(fooPage, hasSize(lessThan(10 + 1)));
}
 

public void testScrollingJoinFetchesPositioning() {
	TestData data = new TestData();
	data.prepare();

	Session s = openSession();
	Transaction txn = s.beginTransaction();

	ScrollableResults results = s
	        .createQuery( "from Animal a left join fetch a.offspring where a.description like :desc order by a.id" )
	        .setString( "desc", "root%" )
	        .scroll();

	results.first();
	Animal animal = ( Animal ) results.get( 0 );
	assertEquals( "first() did not return expected row", data.root1Id, animal.getId() );

	results.scroll( 1 );
	animal = ( Animal ) results.get( 0 );
	assertEquals( "scroll(1) did not return expected row", data.root2Id, animal.getId() );

	results.scroll( -1 );
	animal = ( Animal ) results.get( 0 );
	assertEquals( "scroll(-1) did not return expected row", data.root1Id, animal.getId() );

	results.setRowNumber( 1 );
	animal = ( Animal ) results.get( 0 );
	assertEquals( "setRowNumber(1) did not return expected row", data.root1Id, animal.getId() );

	results.setRowNumber( 2 );
	animal = ( Animal ) results.get( 0 );
	assertEquals( "setRowNumber(2) did not return expected row", data.root2Id, animal.getId() );

	txn.commit();
	s.close();

	data.cleanup();
}
 

protected int doRebuildIndex() throws Exception {
	FullTextSession fullTextSession = (FullTextSession) entityManager.getDelegate();
	fullTextSession.setFlushMode(org.hibernate.FlushMode.MANUAL);
	fullTextSession.setCacheMode(org.hibernate.CacheMode.IGNORE);
	fullTextSession.purgeAll(NodeDocumentVersion.class);
	fullTextSession.getSearchFactory().optimize(NodeDocumentVersion.class);

	String query = "select ndv from NodeDocumentVersion ndv";
	ScrollableResults cursor = fullTextSession.createQuery(query).scroll();
	cursor.last();
	int count = cursor.getRowNumber() + 1;
	log.warn("Re-building Wine index for " + count + " objects.");

	if (count > 0) {
		int batchSize = 300;
		cursor.first(); // Reset to first result row
		int i = 0;

		while (true) {
			fullTextSession.index(cursor.get(0));

			if (++i % batchSize == 0) {
				fullTextSession.flushToIndexes();
				fullTextSession.clear(); // Clear persistence context for each batch
				log.info("Flushed index update " + i + " from Thread "
						+ Thread.currentThread().getName());
			}

			if (cursor.isLast()) {
				break;
			}

			cursor.next();
		}
	}

	cursor.close();
	fullTextSession.flushToIndexes();
	fullTextSession.clear(); // Clear persistence context for each batch
	fullTextSession.getSearchFactory().optimize(NodeDocumentVersion.class);

	return count;
}
 

/**
 * Create a {@link ScrollIterator}.
 *
 * @param sr scrollable result set
 */
public ScrollIterator(ScrollableResults sr) {
	this.sr = sr;
	hasNext = sr.first();
}