Blob manipulation
From: Aviran Levy <avlevy2k_at_hotmail.com>
Date: Fri, 26 Oct 2001 10:51:10 -0400
Message-ID: <5MeC7.380$0N4.47642_at_news.shore.net>
Thanks, However,
I set the Autocommit to be false in the connection object but its still not working.
Any info will be helpfull
Thanks,
-- Avi
"ek" <nirkeen_at_saber.net> wrote in message news:ttipi1nrl0bm37_at_corp.supernews.com...
> Have you verified autocommit is false on the connection? The default is
> true.
>
>
> Aviran Levy wrote in message ...
> >Thanks for the help,
> >First I would like to ask if the book "Oracle8i JDBC Developer's Guide
and
> >Reference" is available online.
> >
> >As for the solution you described in your message, When I try to run it I
> >get an exception thrown from the oracle server saying that the "row
> >containing the lob object is not locked". I know that if I run a stored
> >procedure to manipulate a BLOB object I can lock the row by adding the
'for
> >update' to the select query and the 'commit' after making the
modification.
> >That's obviously not the case here. any ideas how to lock a row in java
> >code?
> >
> >Furthermore, do you happen to know a place when I can get the
documentation
> >for the oracle BLOB object since I also need to access the data in the
> BLOB.
> >in the example you gave in your message I would like also to do the
> >opposite - how is it possible to get data from the BLOB object and store
it
> >in a new file ?
> >
> >Thanks a lot
> >-- Avi
> >
> >"Sergey M" <msu_at_pronto.msk.ru> wrote in message
> >news:9r8lnt$116k$1_at_serv2.vsi.ru...
> >> "Aviran Levy" <avlevy2k_at_hotmail.com> сообщил/сообщила в новостях
> >следующее:
> >> news:ZfAB7.133$0N4.17635_at_news.shore.net...
> >> > Hi,
> >> > From a java application I'm trying to do:
> >> > ...
> >> > Blob b = rs.getBlob("ZIP_FILE");
> >> > b.setBytes(1,byteArray);
> >> > ...
> >> > but apparently I get a runtime exception since my oracle jdbc driver
> >> doesn't
> >> > have implementation for the setBytes method. I probably need a newer
> >> oracle
> >> > jdbc driver. Is anyone know where can I find one?
> >> > Is anyone having that problem too?
> >> > My goal is to store a zip file on the Oracle server and manipulate it
> >from
> >> > the java application (avoiding calls for store procedures). If anyone
> >> knows
> >> > a better way to do that then please... I'll appreciate any help about
> >it.
> >> > Note: to use setBytes you have to use JDK1.4
> >> > Thanks,
> >> > -- Avi
> >>
> >> 1. Begin by using SQL statements to create the BLOB entry in the table.
> >> Use the empty_blob syntax to create the BLOB locator.
> >>
> >> stmt.execute ("INSERT INTO my_blob_table VALUES ('row1',
> >> empty_blob())");
> >>
> >> 2. Get the BLOB locator from the table.
> >>
> >> BLOB blob;
> >> cmd = "SELECT * FROM my_blob_table WHERE X='row1'";
> >> ResultSet rest = stmt.executeQuery(cmd);
> >> BLOB blob = ((OracleResultSet)rset).getBLOB(2);
> >>
> >> 3. Declare a file handler for the john.gif file, then print the length
of
> >> the file. This value will be used later
> >> to ensure that the entire file is read into the BLOB. Next, create
a
> >> FileInputStream object to read the
> >> contents of the GIF file, and an OutputStream object to retrieve
the
> >> BLOB as a stream.
> >>
> >> File binaryFile = new File("YOUR_ZIP_FILE");
> >> System.out.println("john.gif length = " + binaryFile.length());
> >> FileInputStream instream = new FileInputStream(binaryFile);
> >> OutputStream outstream = blob.getBinaryOutputStream();
> >>
> >>
> >> 4. Call getBufferSize() to retrieve the ideal buffer size (according to
> >> calculations by the JDBC driver) to use in
> >> writing to the BLOB, then create the buffer byte array.
> >>
> >> int size = blob.getBufferSize();
> >> byte[] buffer = new byte[size];
> >> int length = -1;
> >>
> >> 5. Use the read() method to read the GIF file to the byte array buffer,
> >then
> >> use the write() method to write it to
> >> the BLOB. When you finish, close the input and output streams.
> >>
> >> while ((length = instream.read(buffer)) != -1)
> >> outstream.write(buffer, 0, length);
> >> instream.close();
> >> outstream.close();
> >>
> >> This fragment is from "Oracle8i JDBC Developer's Guide and Reference"
> >> charpter 7 "Working with LOBs and BFILEs"
> >>
> >> Sergey M.
> >>
> >> P.S. Knowledge is of two kinds. We know a subject ourselves, or we know
> >> where we can find information upon it. --Samuel Johnson
> >>
> >>
> >
> >
> >
> >
>
>
Received on Fri Oct 26 2001 - 16:51:10 CEST
Date: Fri, 26 Oct 2001 10:51:10 -0400
Message-ID: <5MeC7.380$0N4.47642_at_news.shore.net>
Thanks, However,
I set the Autocommit to be false in the connection object but its still not working.
Any info will be helpfull
Thanks,
-- Avi
"ek" <nirkeen_at_saber.net> wrote in message news:ttipi1nrl0bm37_at_corp.supernews.com...
> Have you verified autocommit is false on the connection? The default is
> true.
>
>
> Aviran Levy wrote in message ...
> >Thanks for the help,
> >First I would like to ask if the book "Oracle8i JDBC Developer's Guide
and
> >Reference" is available online.
> >
> >As for the solution you described in your message, When I try to run it I
> >get an exception thrown from the oracle server saying that the "row
> >containing the lob object is not locked". I know that if I run a stored
> >procedure to manipulate a BLOB object I can lock the row by adding the
'for
> >update' to the select query and the 'commit' after making the
modification.
> >That's obviously not the case here. any ideas how to lock a row in java
> >code?
> >
> >Furthermore, do you happen to know a place when I can get the
documentation
> >for the oracle BLOB object since I also need to access the data in the
> BLOB.
> >in the example you gave in your message I would like also to do the
> >opposite - how is it possible to get data from the BLOB object and store
it
> >in a new file ?
> >
> >Thanks a lot
> >-- Avi
> >
> >"Sergey M" <msu_at_pronto.msk.ru> wrote in message
> >news:9r8lnt$116k$1_at_serv2.vsi.ru...
> >> "Aviran Levy" <avlevy2k_at_hotmail.com> сообщил/сообщила в новостях
> >следующее:
> >> news:ZfAB7.133$0N4.17635_at_news.shore.net...
> >> > Hi,
> >> > From a java application I'm trying to do:
> >> > ...
> >> > Blob b = rs.getBlob("ZIP_FILE");
> >> > b.setBytes(1,byteArray);
> >> > ...
> >> > but apparently I get a runtime exception since my oracle jdbc driver
> >> doesn't
> >> > have implementation for the setBytes method. I probably need a newer
> >> oracle
> >> > jdbc driver. Is anyone know where can I find one?
> >> > Is anyone having that problem too?
> >> > My goal is to store a zip file on the Oracle server and manipulate it
> >from
> >> > the java application (avoiding calls for store procedures). If anyone
> >> knows
> >> > a better way to do that then please... I'll appreciate any help about
> >it.
> >> > Note: to use setBytes you have to use JDK1.4
> >> > Thanks,
> >> > -- Avi
> >>
> >> 1. Begin by using SQL statements to create the BLOB entry in the table.
> >> Use the empty_blob syntax to create the BLOB locator.
> >>
> >> stmt.execute ("INSERT INTO my_blob_table VALUES ('row1',
> >> empty_blob())");
> >>
> >> 2. Get the BLOB locator from the table.
> >>
> >> BLOB blob;
> >> cmd = "SELECT * FROM my_blob_table WHERE X='row1'";
> >> ResultSet rest = stmt.executeQuery(cmd);
> >> BLOB blob = ((OracleResultSet)rset).getBLOB(2);
> >>
> >> 3. Declare a file handler for the john.gif file, then print the length
of
> >> the file. This value will be used later
> >> to ensure that the entire file is read into the BLOB. Next, create
a
> >> FileInputStream object to read the
> >> contents of the GIF file, and an OutputStream object to retrieve
the
> >> BLOB as a stream.
> >>
> >> File binaryFile = new File("YOUR_ZIP_FILE");
> >> System.out.println("john.gif length = " + binaryFile.length());
> >> FileInputStream instream = new FileInputStream(binaryFile);
> >> OutputStream outstream = blob.getBinaryOutputStream();
> >>
> >>
> >> 4. Call getBufferSize() to retrieve the ideal buffer size (according to
> >> calculations by the JDBC driver) to use in
> >> writing to the BLOB, then create the buffer byte array.
> >>
> >> int size = blob.getBufferSize();
> >> byte[] buffer = new byte[size];
> >> int length = -1;
> >>
> >> 5. Use the read() method to read the GIF file to the byte array buffer,
> >then
> >> use the write() method to write it to
> >> the BLOB. When you finish, close the input and output streams.
> >>
> >> while ((length = instream.read(buffer)) != -1)
> >> outstream.write(buffer, 0, length);
> >> instream.close();
> >> outstream.close();
> >>
> >> This fragment is from "Oracle8i JDBC Developer's Guide and Reference"
> >> charpter 7 "Working with LOBs and BFILEs"
> >>
> >> Sergey M.
> >>
> >> P.S. Knowledge is of two kinds. We know a subject ourselves, or we know
> >> where we can find information upon it. --Samuel Johnson
> >>
> >>
> >
> >
> >
> >
>
>
Received on Fri Oct 26 2001 - 16:51:10 CEST