Question

我正在尝试将我的Arraylist写入文本文件并将该文件读回到我的ArrayList中。

我使用：

写出了ArrayList

private static void saveFile(ArrayList<Vehicle> vehs){
        File fileName = new File("VehicleList.txt"); 


        try {
            FileWriter fw = new FileWriter(fileName);
            BufferedWriter output = new BufferedWriter(fw);

            for (int i = 0; i < vehs.size(); i++){
                output.write(vehs.get(i).toString());
                output.newLine();
            }

            output.close();

        } catch (Exception e) {
            JOptionPane.showMessageDialog(null, "I cannot create that file");
        }
    }

但是我在阅读文件时遇到了麻烦，无法填写ArrayList。

这是我用来回读ArrayList的代码：

  private static void readVFile(ArrayList<Vehicle> vehs) throws FileNotFoundException, IOException{
    ObjectInputStream ois = new ObjectInputStream(new FileInputStream("VehicleList.txt"));

    try {

        Object obj = null;
        while ((obj = ois.readObject()) != null) {
            if (obj instanceof Vehicle) {
            Vehicle v = (Vehicle) obj;
            vehs.add(v);
            }
        }

    } catch (Exception e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    finally{
        ois.close();
    }



 }

这个ArrayList需要添加2个构造函数。

构造函数：

public PremiumVehicle(String vehicleID, String description, double dailyRate, int odometer, int allowance, int serLength, int lastOdo) //subclass

public Vehicle(String vehicleID, String description, double dailyRate, int odometer) //Superclass

添加到ArrayList示例：

ArrayList<Vehicle> vehs = new ArrayList<Vehicle>();

vehs.add(new Vehicle("QJT123", "Starlet 99", 35.0, 190000));
vehs.add(new PremiumVehicle("TUX132", "BWM 05  ", 90.0, 12000, 100, 10000, 5000));

当我尝试回读文件时，它会返回给我＆＃34; StreamCorruptedException：无效的流标题：76656879＆＃34;。我如何读回我刚刚写入ArrayList的文本文件？提前感谢您的帮助。

修改

我已尝试使用FileOutputStream和ObjectOutputStream，但现在它没有记录它的内容。

编辑序列化代码：

private static void saveFile(ArrayList<Vehicle> vehs){
        File fileName = new File("VehicleList.txt"); 


        try {
            FileOutputStream fos = new FileOutputStream(fileName);

            ObjectOutputStream oos = new ObjectOutputStream(fos);

            for (int i = 0; i < vehs.size(); i++){
                oos.writeObject(vehs.get(i));
            }

            oos.close();

        } catch (Exception e) {
            JOptionPane.showMessageDialog(null, "I cannot create that file");
        }

}

编写和读取每个ArrayList对象使用多个构造函数和多个值的ArrayList

0 个答案: