Blobs and Clobs must be treated "special" in all Jdbc implementations. They are done via streams -- not via stmt.set* calls (although in jdbc 2 you have a setClob and setBlob -- they are much the same -- see the last referenced link below pointint to technet. The mechanics are nearly identical -- insert empty_clob(), retrieve it, and then stream it).

Here is an example -- it inserts an empty_clob() and then gets it back out -- you have to select OUT (or use the insert into ... returning clob_column into :bind_variable) lob locator and cast as a stream. This shows how to read and write clobs. There :

import java.lang.*;
import java.sql.*;
import java.util.*;
import oracle.jdbc.driver.*;


public class movelr
{
public static void main(String[] args) throws Exception
{
int length;

DriverManager.registerDriver (new OracleDriver());

Connection conn73 = DriverManager.getConnection
("jdbc:oracle:oci8:@ora8idev","scott","tiger");
Connection conn81 = DriverManager.getConnection
("jdbc:oracle:oci8:@ora8idev","scott","tiger");

conn73.setAutoCommit (false);
conn81.setAutoCommit (false);
System.out.println( "connected..." );

// Create statements
PreparedStatement pstmt = conn73.prepareStatement
("select image from image@slack" );

System.out.println( "prepared statement for v7.3..." );

PreparedStatement insertStmt = conn81.prepareStatement
("insert into blob_demo ( x, y ) " +
"values ( ?, empty_blob() )");
System.out.println
( "prepared statement for v8.x BLOB insert..." );

PreparedStatement getStmt = conn81.prepareStatement
("select y from blob_demo where x = ? for update");
System.out.println
( "prepared statement for v8.x BLOB select..." );

ResultSet rset73 = pstmt.executeQuery();
System.out.println
( "executed statement for v7.3 select..." );

for( int i = 0; rset73.next(); i++ )
{
System.out.println( "looping..." );
InputStream is = rset73.getBinaryStream(1);
System.out.println( "Got v7.3 LONG RAW stream..." );

// Insert a new row and get select
// back the BLOB column
insertStmt.setInt(1, i);
insertStmt.executeUpdate();
getStmt.setInt(1, i);
OracleResultSet rset81 =
(OracleResultSet) getStmt.executeQuery();

rset81.next();
OutputStream os =
rset81.getBLOB(1).getBinaryOutputStream();
System.out.println( "Got v8.x BLOB stream..." );

System.out.println( "Moving data from IS to OS..." );
byte buffer[] = new byte[1024];
while ((length = is.read (buffer,0,1024)) != -1)
{
os.write( buffer, 0, length );
}

is.close();
os.close();
rset81.close();
}
rset73.close();
insertStmt.close();
getStmt.close();
pstmt.close();
conn81.commit();
conn73.close();
conn81.close();
}
}


See also:

</code> http://docs.oracle.com/cd/A81042_01/DOC/java.816/a81354/oralob2.htm#1043351 <code>

for more details.