Re: Store a file in a bytea

Hi,

why do you not use ResultSet.getBinaryStream() to read the content?

Bye Thomas


Am Donnerstag, 10. Februar 2011 schrieb mmg:
> Hi all,
>
> I'm creating an application that will store files in a postresql
> database and which will retrieve them later on. I store my data in a
> bytea column. The problem I'm having is that when I retrieve the
> data later and write it out, the resulting file is not the same as
> the original. When I open the file it looks as though the ASCII
> codes were written out instead of the data itself (so it looks as if
> the ASCII was encoded again as ASCII, causing me to see ASCII codes
> when I open the file). I created a simple test program to
> demonstrate this:
>
>         Connection conn =
> DriverManager.getConnection("jdbc:postgresql://localhost/testdb",
> "test", "test");
>         conn.createStatement().executeUpdate("DELETE FROM
testtable");
>         PreparedStatement pstmt = conn.prepareStatement("INSERT
INTO
> testtable(data) VALUES(?)");
>         File file = new File("c:/t.txt");
>         FileInputStream fis = new FileInputStream(file);
>         pstmt.setBinaryStream(1, fis, (int) file.length());
>         pstmt.executeUpdate();
>         ResultSet rs =
conn.createStatement().executeQuery("SELECT * FROM
> testtable");
>         if (rs.next()) {
>             byte[] data = rs.getBytes("data");
>             FileOutputStream fos = new
FileOutputStream("c:/t2.txt");
>             fos.write(data);
>             fos.close();
>         }
>         rs.close();
>         conn.close();
>
> There is one table: testtable with a data colum which is a bytea. I
> read the file c:/t.txt, store this as a stream then read it out
> again and write it to c:/t2.txt. When I open t2.txt, I see the ASCII
> codes instead of the actual text. I don't know what I'm doing wrong.
> I've tried reading it as a stream from the database, but that
> doesn't work either. Any help is much appreciated.