Storing/retreiving Large Objects

FYI. This should have gone to the pgsql-jdbc mail list instead of
pgsql-general.

What version are you using? This area of the code has undergone some
significant work in 7.2. I would suggest you try using the 7.2 jdbc
code (which will run fine against a 7.1 database). Also look at the 7.2
documentation as it also has been updated significantly in this area.

I cannot reproduce your problem using the 7.2 drivers given the test
case below.

thanks,
--Barry

Wieger Uffink wrote:

Thanks for the info, I have taking the general list of the cc.

I have managed to get it to work by taking the poolman connection pooler
out of the equation, and connecting directly through the jdbc (version
7.1). So I guess i need to look for the solution in the poolman package.

THanks
WIeger

On Wed, 2002-01-09 at 19:11, Barry Lind wrote:

FYI. This should have gone to the pgsql-jdbc mail list instead of
pgsql-general.

What version are you using? This area of the code has undergone some
significant work in 7.2. I would suggest you try using the 7.2 jdbc
code (which will run fine against a 7.1 database). Also look at the 7.2
documentation as it also has been updated significantly in this area.

I cannot reproduce your problem using the 7.2 drivers given the test
case below.

thanks,
--Barry

Wieger Uffink wrote:

Hi,

Im trying to store images in my postgres db through jdbc access. The
connections are pooled through poolman. So far I have only tried to get
the manual's example in section 8.5 to work. Ive included the example
below.

I have literally c&p the example and the inserting the image seems to go
well since it results in populated row in table 'images'.
WHen I try to retreive the the image either through ps.getBinaryStream()
or ps.getBlob() I get a Class cast exception thrown at me, nl:

java.lang.ClassCastException: java.lang.Integer
at
com.codestudio.sql.PoolManResultSet.getBlob(PoolManResultSet.java:414)

Apparently the oid stored in the table is retreived as an integer, which
obviously cannot be cast into a BinaryStream.
ANyone have any idea what could be going wrong here? Maybe some poolman
type mapping configuration or something.

Thanks in advance,
Wieger

//Example 8-2. Using the JDBC Large Object Interface

//For example, suppose you have a table containing the file name of an
//image and you have a large object containing that image:

//CREATE TABLE images (imgname text, imgoid oid);

//To insert an image, you would use:

File file = new File("myimage.gif");
FileInputStream fis = new FileInputStream(file);
PreparedStatement ps = conn.prepareStatement("INSERT INTO images VALUES
(?, ?)"); (1)
ps.setString(1, file.getName());
ps.setBinaryStream(2, fis, file.length());
ps.executeUpdate();
ps.close();
fis.close();

//retreiving
PreparedStatement ps = con.prepareStatement("SELECT oid FROM images
WHERE name=?");
ps.setString(1, "myimage.gif");
ResultSet rs = ps.executeQuery();
if (rs != null) {
while(rs.next()) {
InputStream is = rs.getBinaryInputStream(1);
// use the stream in some way here
is.close();
}
rs.close();
}
ps.close();

--

Wieger Uffink
tel: +31 20 468 6868
fax: +31 20 470 6905
web: http://www.usmedia.nl
email: wieger@usmedia.nl

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