Hibernate + Resteasy + Blobstream

Question

i'm using resteasy and saving blobs with hibernate

i've configured the open session in view

my rest-handler is non-transactional, my service which retrieves the java.sql.blobs is transactional.

The problem: after retrieving the blob in the service the jdbc-connection is closed by the HibernateTransactionManager:doCleanupAfterCompletion (the hibernate session is not closed)

so rest can't read the blob stream later, because it works only if the same jdbc-connection is still open

how can i hibernate teach not to close the jdbc-connection after the transactional service-function?

It should close it when the session is closed

Answer 1

i solved it by creating a Provider for Blob, adopded from InputSTream-Provider

@Provider
@Produces("*/*")
public class BlobProvider implements MessageBodyWriter<Blob> {

    public boolean isWriteable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) {
        return Blob.class.isAssignableFrom(type);
    }

    public long getSize(Blob blob, Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) {
        return -1;
    }

    public void writeTo(Blob blob, Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType, MultivaluedMap<String, Object> httpHeaders, OutputStream entityStream) throws IOException {
        SessionFactory sessionFactory = (SessionFactory) Utils.getBean("sessionFactory");
        sessionFactory.getCurrentSession().beginTransaction();
        InputStream inputStream = null;
        try {
            inputStream = blob.getBinaryStream();
            int c = inputStream.read();
            if (c == -1) {
                httpHeaders.putSingle(HttpHeaderNames.CONTENT_LENGTH, Integer.toString(0));
                entityStream.write(new byte[0]); // fix RESTEASY-204
                return;
            } else
                entityStream.write(c);
            ProviderHelper.writeTo(inputStream, entityStream);
        } catch (SQLException e) {
            Utils.logError(e);
        } finally {
            if (inputStream != null)
                inputStream.close();
        }
        sessionFactory.getCurrentSession().getTransaction().commit();
    }
}