jdbc

public class UsersDAO {
	
	private Connection con;
	
	public UsersDAO(Connection con){
		this.con = con;
	}
	
	public UsersDataSet get(long id) throws SQLException{
		TExecutor exec = new TExecutor();
		return exec.execQuery(con, "select * from users where id=" + id, new TResultHandler<UsersDataSet>(){

			public UsersDataSet handle(ResultSet result) throws SQLException {
				result.next();
                return new UsersDataSet(result.getLong(1), result.getString(2));
			}
			
		});
	}
}

public class TExecutor {
	public <T> T execQuery(Connection connection,
			String query,
			TResultHandler<T> handler)
			throws SQLException {
		Statement stmt = connection.createStatement();
		stmt.execute(query);
		ResultSet result = stmt.getResultSet();
		T value = handler.handle(result);
		result.close();
		stmt.close();

		return value;
	}

}