Use getBlob to read blob data from database and convert blob data to byte[] array in Java

import java.io.InputStream;
import java.sql.Blob;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
/* w  ww .j  a v a 2 s. c om*/
public class Main {
  public static void main(String[] argv) throws Exception {
    String driverName = "com.jnetdirect.jsql.JSQLDriver";
    Class.forName(driverName);

    String serverName = "127.0.0.1";
    String portNumber = "1433";
    String mydatabase = serverName + ":" + portNumber;
    String url = "jdbc:JSQLConnect://" + mydatabase;
    String username = "username";
    String password = "password";

    Connection connection = DriverManager.getConnection(url, username, password);
    Statement stmt = connection.createStatement();
    ResultSet rs = stmt.executeQuery("SELECT col_blob FROM mysql_all_table");

    if (rs.next()) {
      Blob blob = rs.getBlob("col_blob");
      long blobLength = blob.length();

      int pos = 1; // position is 1-based
      int len = 10;
      byte[] bytes = blob.getBytes(pos, len);

      InputStream is = blob.getBinaryStream();
      int b = is.read();
    }
  }
}