트랜젝션 처리.

//Dao

public int BoardDelete(String boardNum,Connection conn) throws Exception{
  Statement stmt = null;
  int cnt = 0;
  try{
   conn = DBConnections.getConnection();
   stmt = conn.createStatement();
   cnt = stmt.executeUpdate(getQueryMethod(Integer.parseInt(boardNum)));
  }
  catch(Exception e){
   e.printStackTrace();
   throw e;
  }
  finally{
   close.release(stmt, null);    //connection 부분은 열어둠.
  }
  return cnt;
 }

//서비스

public void deleteService(String boardNum) throws Exception{
  Connection conn = null;
  try{
   conn = DBConnections.getConnection();
   conn.setAutoCommit(false);                            //자동 커밋안함
   int cnt = dao.BoardDelete(boardNum,conn);
   if(cnt != 1){
    throw new Exception("Delete Count Fail");
   }
   conn.commit();                                                //넣음.
  }
  catch(Exception e){
   conn.rollback();                                            //문제 발생시 롤백함.
   e.printStackTrace();
   throw e;
  }
  finally{
   if(conn != null){
    conn.close();                                                //Connection 닫음.
   }
  }
 }