Storing large file in Oracle

Question

Hi,
We have a requirement where we need to persist file (upto 100MB or more) into the database.
We are using Hibernate as the ORM.
The approaches that we are considering are:
1. use a BLOB field to upload the file.
What I am doing here is
SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();
Session session = sessionFactory.openSession();
Transaction txn = session.beginTransaction();
Bean bean = new Bean();
bean.setFilename("testdata1.doc");
byte[] dummy={0};
bean.setFilecontent(Hibernate.createBlob(dummy));
session.save(bean);
session.flush();
session.refresh(bean);
OutputStream out = ((oracle.sql.BLOB)bean.getFilecontent()).setBinaryStream(1);
FileInputStream fis = new FileInputStream(new File("testdata1.doc"));
int size=1024;
byte[] bytes= new byte[size];
int res = fis.read(bytes);
while(res!=-1){
out.write((bytes));
System.err.println("+++"+size+"/"+fis.available());
bytes= new byte[size];
res = fis.read(bytes);
fis.close();
session.save(bean);
session.flush();
txn.commit();
session.close();
File content in bean is a java.sql.Blob
Then I read this out of the DB and write to a file as shown here
SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();
Session session = sessionFactory.openSession();
Transaction txn = session.beginTransaction();
Criteria c = session.createCriteria(Bean.class);
c.add(Restrictions.like("filename", "testdata1.doc"));
Bean bean = (Bean)c.uniqueResult();
InputStream in = ((oracle.sql.BLOB)bean.getFilecontent()).getBinaryStream();
FileOutputStream fos = new FileOutputStream("retrieved_testdata.doc");
int size=1024;
byte[] bytes = new byte[size];
int res = in.read(bytes);
while(res!=-1){
fos.write((bytes));
System.err.println("---"+size+"/"+in.available());
bytes = new byte[size];
res = in.read(bytes);
fos.close();
session.delete(bean);
session.flush();
txn.commit();
session.close();
I see that the retrieved file is 6KB less than the original and it wont open in word :(
I tried Base64 encoding the bytes before writing them to the BLOB, still I can see a discrepancy in the file size and it wont open.
The other approach that we tried was to read the file, Base64 the bytes and put them into a CLOB/NCLOB field. In that case when I retrieve the file out of the database and write it out, the file is smaller by a few hundred KB and the file wont open.
My Oracle database is Oracle 10.2.0.2 64 bit on RHEL
I am using Oracle 10.2.0.4 drivers to be compatible with the application from where we retrieve some other data.
We are using Java 1.5
Am I doing something wrong?
What is the correct way to do this?
UPDATE:_
I am able to make it work using
bean.setFilecontent(Hibernate.createBlob(fis));
But there might be a case where we have to write in sets of byte arrays. If it is not possible to make it work writing in sets of byte arrays, then we could look at enforcing this.
Thanks
Hari
Edited by: Wilddev007 on Feb 10, 2009 11:47 AM

Answer 1

This seems like a seriously bad idea. What is the benefit of 'saving a 100mb file'
in the DBMS as opposed to copying it via ftp to some remote machine or other
disk?