Example: Using BLOBs

/////////////////////////////////////////
// UseBlobs is an example application 
// that shows some of the APIs associated
// with Blob objects.
//
// This program must be run after
// the PutGetBlobs program has completed.
/////////////////////////////////////////
import java.sql.*;

public class UseBlobs {
   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);


      // Determine the length of a LOB.
      long end = blob1.length();
      System.out.println("Blob1 length is " + blob1.length());

      // When working with LOBs, all indexing that is related to them
      // is 1-based, and is not 0-based like strings and arrays.     
      long startingPoint = 450;
      long endingPoint = 500;

      // Obtain part of the BLOB as a byte array.
      byte[] outByteArray = blob1.getBytes(startingPoint, (int)endingPoint);

      // Find where a sub-BLOB or byte array is first found within a
      // BLOB. The setup for this program placed two identical copies of 
      // a random BLOB into the database. Thus, the start position of the 
      // byte array extracted from blob1 can be found in the starting
      // position in blob2. The exception would be if there were 50
      // identical random bytes in the LOBs previously.
      long startInBlob2 = blob2.position(outByteArray, 1);

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

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