爲什麼我無法添加基於我的DAO的訂單？

Question

我正在訓練營中進行作業。

我需要添加訂單並將其寫入文件。我能夠瀏覽所有的課程，並說它已成功添加，但沒有寫入文件。我的代碼寫到一個文件是正確的，因爲我被告知，但在我添加的方法，我已經發布似乎有東西了。

這裏是我的代碼：

public void writeToOrder() throws flooringMasteryPersistenceException { 
    PrintWriter out = null; 
    for (LocalDate entry : orders.keySet()) { 
     try { 
      out = new PrintWriter (new FileWriter (DateToFile (entry))); 
     } catch (IOException ex) { 
      System.out.println ("cannot write to file."); 
     } 

     List<Order> purchases = orders.get (entry); 
     for (Order entryPoint : purchases) { 
      out.println (
       entryPoint.getOrderNumber() + DELIMITER + 
       entryPoint.getDate() + DELIMITER + 
       entryPoint.getCustomerName() + DELIMITER + 
       entryPoint.getState() + DELIMITER + 
       entryPoint.getTaxRate() + DELIMITER + 
       entryPoint.getProductType() + DELIMITER + 
       entryPoint.getArea() + DELIMITER + 
       entryPoint.getCostPerSquareFoot() + DELIMITER + 
       entryPoint.getLaborCostPerSquareFoot() + DELIMITER + 
       entryPoint.getMaterialCost() + DELIMITER + 
       entryPoint.getLaborCost() + DELIMITER + 
       entryPoint.getTax() + DELIMITER + 
       entryPoint.getTotal() 
      ); 

      out.flush(); 
     } 

     out.close(); 
    } 
} 

@Override 
public void save() throws flooringMasteryPersistenceException { 
    writeToOrder(); 
} 

@Override 
public Order addOrder (Order order) throws flooringMasteryPersistenceException { 
    // List< Order> newDate = orders.get (LocalDate.now()); 
    // if (!orders.containsKey (order.getDate())) { 
    //  orders.put(order.getDate(), Set <String> dates); 
    // } 
    // orders.get (order.getDate()); 
    // newDate.add (order); 
    // 
    // save(); 
    //   
    // orders.put (order.getDate(),); 
    // order.setOrderNumber (orderNumber); 
    // return order; 
} 

Answer 1

看到這裏，

out = new PrintWriter (new FileWriter (DateToFile (entry)));

你不需要new FileWriter(...)一部分，只需指定如下的文件名：

PrintWriter out = new PrintWriter("filename");