On Friday 04 April 2008, Ignacio Andreu wrote:
> I review the conversation If you're using PostgreSQL, the actual
> InputStream / Reader don't have support for PostgreSQL, although if you've
> a good solution for Large Object in PostgreSQL please e-mail me.
>
When I have got everything working I will post the code. It seems to work
well. It actually should not be too difficult to be wrapped up as an
InputStream. But it does use the LargeObjectManager rather than
embedded LOB fields.
The write code seems to work, and now I just to dot the i's and cross the
t's on the read code.
The write code reads:-
private long writeObject(File file, EntityManager em) throws Exception {
DelegatingConnection conn =
(DelegatingConnection)OpenJPAPersistence.cast(em).getConnection();
try {
conn.setAutoCommit(false);
Connection c = conn.getInnermostDelegate();
if(c.isClosed()) throw new SQLException("innermost
delegate is closed");
PGConnection pgconn = (PGConnection)c;
LargeObjectManager lom = pgconn.getLargeObjectAPI();
long oid = lom.createLO();
LargeObject lo = lom.open(oid,
LargeObjectManager.WRITE);
FileInputStream fis = new FileInputStream(file);
byte[]buffer = new byte[32768];
int len = 0;
while( ( len = fis.read(buffer)) > 0) {
lo.write(buffer, 0, len);
}
lo.close();
fis.close();
conn.commit();
return oid;
} finally {
try { conn.close(); } catch (Exception e) { /* */ }
}
}
This method returns the OID of the large object, reading the object from
the File.
David
>
> - Ignacio
>
> On Fri, Apr 4, 2008 at 7:16 PM, Ignacio Andreu <[EMAIL PROTECTED]> wrote:
> > Hi,
> >
> > The InputStream / reader support is not documented yet, I want to provide
> > some documentation soon.
> >
> >
> > BTW I sent a patch for the InputStream / Reader support a week ago, this
> > patch solves some bugs, Can you review and commit the patch? Thanks in
> > advance!!
> >
> >
> >
> >
> > On Fri, Apr 4, 2008 at 5:32 PM, Patrick Linskey <[EMAIL PROTECTED]>
> >
> > wrote:
> > > > > Additionally, note that OpenJPA 1.1.0-SNAPSHOT has support for
> > >
> > > fields
> > >
> > > > > of type InputStream; with this support, OpenJPA will never fully
> > >
> > > load
> > >
> > > > > the data into memory.
> > > >
> > > > I can see how this will work for readonly values, how about write
> > >
> > > ones?
> > >
> > > > Also looking in the 1.1.0 manual I can not find any reference to
> > >
> > > InputStream.
> > >
> > > I think it hasn't been documented yet. Take a look at
> > > InputStreamLobTest for an example.
> > >
> > > For write values, you simply assign the InputStream field to the
> > > stream that OpenJPA should read from when streaming to the database:
> > >
> > > @Entity
> > > public class Picture {
> > > @Persistent private InputStream data;
> > >
> > > public void streamContentsIntoDatabase(InputStream is) {
> > > data = is;
> > > }
> > >
> > > public InputStream streamContentsFromDatabase() {
> > > return is;
> > > }
> > > }
> > >
> > > -Patrick
> > >
> > > On Fri, Apr 4, 2008 at 6:57 AM, David Goodenough
> > >
> > > <[EMAIL PROTECTED]> wrote:
> > > > On Tuesday 01 April 2008, Patrick Linskey wrote:
> > > > > Or, even more simply:
> > > > >
> > > > > em.getTransaction().begin();
> > > > > Connection c = OpenJPAPersistence.cast(em).getConnection();
> > > >
> > > > Actually for what I need I need to cast this to a
> > >
> > > DelegatingConnection
> > >
> > > > and then get the PGConnection by casting its InnermostDelegate.
> > > > But yes, this works - thank you.
> > > >
> > > > > try {
> > > > >
> > > > > ...
> > > > > } finally {
> > > > > c.close(); // the connection is a wrapper; this decrements the
> > > > > reference count
> > > > > }
> > > > > em.getTransaction().commit();
> > > > >
> > > > > Additionally, note that OpenJPA 1.1.0-SNAPSHOT has support for
> > >
> > > fields
> > >
> > > > > of type InputStream; with this support, OpenJPA will never fully
> > >
> > > load
> > >
> > > > > the data into memory.
> > > >
> > > > I can see how this will work for readonly values, how about write
> > >
> > > ones?
> > >
> > > > Also looking in the 1.1.0 manual I can not find any reference to
> > >
> > > InputStream.
> > >
> > > > David
> > > >
> > > > > -Patrick
> > > > >
> > > > > On Mon, Mar 31, 2008 at 8:31 PM, Pinaki Poddar
> > > > > <[EMAIL PROTECTED]>
> > >
> > > wrote:
> > > > > > Hi,
> > > > > > Following should work:
> > > > > >
> > > > > >
> > > > > >
> > > > > > import javax.persistence.EntityManager;
> > > > > > import org.apache.openjpa.kernel.Broker;
> > > > > > import org.apache.openjpa.jdbc.kernel.JDBCStore;
> > > > > > import org.apache.openjpa.persistence.JPAFacadeHelper;
> > > > > > import java.sql.Connection;
> > > > > >
> > > > > > EntityManager em = emf.createEntityManager();
> > > > > > Broker broker = JPAFacadeHelper.toBroker(em);
> > > > > >
> > > > > > JDBCStore store = (JDBCStore)broker.getStoreManager();
> > > > > > Connection con = store.getConnection();
> > > > > >
> > > > > > David Goodenough-3 wrote:
> > > > > > > I need to get to the real JDBC Connection object so that I
> > > > > > > can
> > >
> > > do some
> > >
> > > > > > > processing using Postgresql extensions (in particular the
> > >
> > > LargeObject
> > >
> > > > > > > support). I do not expect OpenJPA to understand what I am
> > >
> > > doing, but
> > >
> > > > > > > I need to access the Connection object and I need what I do
> > > > > > > to
> > >
> > > be
> > >
> > > > > > > in the same transaction as that used by OpenJPA (so also it
> > >
> > > needs to
> > >
> > > > > > > be the same transaction).
> > > > > > >
> > > > > > > The manual suggests:-
> > > > > > >
> > > > > > > OpenJPAEntityManagerFactory kemf =
> > >
> > > OpenJPAPersistence.cast(emf);
> > >
> > > > > > > OpenJPAConfiguration conf = kemf.getConfiguration();
> > > > > > >
> > > > > > > on page 190, but kemf does not have a getConfiguration method
> > > > > > > according to Eclipse (using OpenJPA 1.0.2).
> > > > > > >
> > > > > > > The OpenJPAConfiguration javadoc is not much use either in
> > >
> > > that it
> > >
> > > > > > > does tell me where to get it from.
> > > > > > >
> > > > > > > Any ideas?
> > > > > > >
> > > > > > > David
> > > > > >
> > > > > > --
> > > > > > View this message in context:
> > >
> > > http://www.nabble.com/How-to-get-I-get-to-the-read-JDBC-Connection-obje
> > >ct
> > >
> > > > > >...-tp16400383p16401689.html Sent from the OpenJPA Users mailing
> > >
> > > list
> > >
> > > > > > archive at Nabble.com.
> > >
> > > --
> > > Patrick Linskey
> > > 202 669 5907
