Example: Update BLOBs

/////////////////////////////////////////
// UpdateBlobs is an example application 
// that shows some of the APIs providing
// support for changing Blob objects 
// and reflecting those changes to the 
// database.
//
// This program must be run after
// the PutGetBlobs program has completed.
/////////////////////////////////////////
import java.sql.*;

public class UpdateBlobs {
   public static void main(String[] args) 
   throws SQLException 
   {
       // Register the native JDBC driver.
       try {
          Class.forName("com.ibm.db2.jdbc.app.DB2Driver");
      } catch (Exception e) {
          System.exit(1);  // Setup error.
      }
          
      Connection c = DriverManager.getConnection("jdbc:db2:*local");    
      Statement s = c.createStatement();
      
      ResultSet rs = s.executeQuery("SELECT * FROM CUJOSQL.BLOBTABLE");

      rs.next();
      Blob blob1 = rs.getBlob(1);
      rs.next();
      Blob blob2 = rs.getBlob(1);


      // Truncate a BLOB.
      blob1.truncate((long) 150000);
      System.out.println("Blob1's new length is " + blob1.length());

      // Update part of the BLOB with a new byte array.
      // The following code obtains the bytes that are at 
      // positions 4000-4500 and set them to positions 500-1000.  

      // Obtain part of the BLOB as a byte array.
      byte[] bytes = blob1.getBytes(4000L, 4500);

      int bytesWritten = blob2.setBytes(500L, bytes);

      System.out.println("Bytes written is " + bytesWritten);

      // The bytes are now found at position 500 in blob2
      long startInBlob2 = blob2.position(bytes, 1);

      System.out.println("pattern found starting at position " + startInBlob2);

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