CODEWITHSUNDEEP
javaoracle-databaseblobclasscastexception
netic
netic

Reputation: 2944

Why I cannot cast oracle BLOB from native java Blob

I am reading file from ResultSet and it's required to save file into Oracle Database.

...
ResultSet rs = ...
java.sql.Blob myfile = rs.getBlob("field")
java.io.OutputStream os = ((oracle.sql.BLOB) myfile).getBinaryOutputStream();

I get get this error message

java.lang.ClassCastException

Any one have solution to this? Thanks!

Upvotes: 4

Views: 18910

Answers (3)

netic
netic

Reputation: 2944

I have found the solution. I'd like to share with those who has this problem.

The code to get outputstream from oracle blob is:

java.io.OutputStream os = ((oracle.sql.BLOB) myBlob).setBinaryStream(1L);

setBinaryStream() is actually returning java.io.OutputStream object

Upvotes: 4

Thilo
Thilo

Reputation: 262474

You seem to not have an oracle.sql.BLOB there (if you did, it should work, BLOB implements Blob). What does the ClassCastException say it is?

What version of Oracle and what version of the JDBC driver are you using?

getBinaryOutputStream is deprecated anyway, you should use setBinaryStream in the JDBC (3.0) interface, which probably removes the need to go to Oracle's internal class at all.

Upvotes: 3

Dan Vinton
Dan Vinton

Reputation: 26769

java.sql.Blob is an interface. Presumably the implementation returned in your ResultSet is a different implementation to oracle.sql.BLOB?

What does myfile.getClass() return?

Upvotes: 3

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