Example: BLOB

/////////////////////////////////////////
// PutGetBlobs is an example application 
// that shows how to work with the JDBC
// API to obtain and put BLOBs to and from
// database columns.
//
// The results of running this program 
// are that there are two BLOB values
// in a new table. Both are identical
// and contain 500k of random byte 
// data.
/////////////////////////////////////////
import java.sql.*;
import java.util.Random;

public class PutGetBlobs {
   public static void main(String[] args) 
   throws SQLException 
   {   
      // Establish a Connection and Statement with which to work.
      Connection c = DriverManager.getConnection("jdbc:db2:*local");    
      Statement s = c.createStatement();
      
      // Clean up any previous run of this application.
      try {
          s.executeUpdate("DROP TABLE CUJOSQL.BLOBTABLE");
      } catch (SQLException e) {
          // Ignore it - assume the table did not exist.
      }

      // Create a table with a BLOB column. The default BLOB column
      // size is 1 MB.
      s.executeUpdate("CREATE TABLE CUJOSQL.BLOBTABLE (COL1 BLOB)");

      // Create a PreparedStatement object that allows you to put
      // a new Blob object into the database.
      PreparedStatement ps = c.prepareStatement("INSERT INTO CUJOSQL.BLOBTABLE VALUES(?)");

      // Create a big BLOB value...
      Random random = new Random ();
      byte [] inByteArray = new byte[500000];
      random.nextBytes (inByteArray);

      // Set the PreparedStatement parameter. Note: This is not 
      // portable to all JDBC drivers. JDBC drivers do not have 
      // support when using setBytes for BLOB columns. This is used to
      // allow you to generate new BLOBs. It also allows JDBC 1.0
      // drivers to work with columns containing BLOB data.
      ps.setBytes(1, inByteArray);

      // Process the statement, inserting the BLOB into the database.
      ps.executeUpdate();

      // Process a query and obtain the BLOB that was just inserted out  
      // of the database as a Blob object.
      ResultSet rs = s.executeQuery("SELECT * FROM CUJOSQL.BLOBTABLE");
      rs.next();
      Blob blob = rs.getBlob(1);

      
      // Put that Blob back into the database through
      // the PreparedStatement.
      ps.setBlob(1, blob);
      ps.execute();

      c.close(); // Connection close also closes stmt and rs.
   }
}