Question

我正在尝试将对象数组保存/加载到普通的.txt文件中。我对序列化知之甚少，但我认为我已正确使用它将对象数组写入.txt文件。单独打开时，.txt文件完全不可读（正常英文）。我正确地将它写入文件吗？以及如何将其读入该计划？

public class HotelObjects {

/**
 * @param args the command line arguments
 */
public static void main(String[] args) {
    String command;

    Scanner input = new Scanner(System.in);

    Room[] myHotel = new Room[10];
    for (int x = 0; x < myHotel.length; x++) {
    myHotel[x] = new Room();
    }

    String roomName;
    int roomNum = 0;

    while (roomNum < 11) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Enter command : ");
        command = input.next();
        command = command.toLowerCase();

        if (command.charAt(0) == 'v') {
            viewCustomers(myHotel);
        }

        if (command.charAt(0) == 'a') {
            addCustomers(myHotel);
        }

        if (command.charAt(0) == 'e') {
            emptyRooms(myHotel);
        }

        if (command.charAt(0) == 's') {
            storeData(myHotel);
        }

    }
}

private static void viewCustomers(Room hotelRef []) {
    for (int x = 0; x < 10; x++) {
            System.out.println("room " + x + " occupied by " + hotelRef[x].getName());
        }
}

private static void addCustomers(Room myHotel[]) {
    String roomName;
    int roomNum;
    System.out.println("Enter room number (0-10) or 11 to stop:");
    Scanner input = new Scanner(System.in);
        roomNum = input.nextInt();
        System.out.println("Enter name for room " + roomNum + " :");
        roomName = input.next();
        myHotel[roomNum].setName(roomName);
}

private static void emptyRooms(Room[] myHotel) {
    for (int x = 0; x < 10; x++ )
        if (myHotel[x].getName().equals("e"))System.out.println("room " + x + " is empty");
}

private static void storeData(Room [] myHotel) {
    try{
        FileOutputStream fos= new FileOutputStream("C:\\Users\\Ganz\\Documents\\NetBeansProjects\\HotelObjects\\HotelObject.dat");
        ObjectOutputStream oos= new ObjectOutputStream(fos);
        oos.writeObject(myHotel);
        oos.close();
        fos.close();
    }catch(IOException ioe){
    }
  }
}

这是Room类（如果需要）：

public class Room implements Serializable {


private String mainName;
int guestsInRoom;

public Room() {
    mainName = "e";
    System.out.println("made a room ");
}

public void setName(String aName) {
    mainName = aName;
}

public String getName() {
    return mainName;
}
}

Answer 1

使用ObjectInputStream和强制转换从文件加载数组。并且您需要在写入结束时（在关闭之前）刷新流。

Answer 2

编写ObjectOutputStream的结果应该是机器可读的，而不是人类可读的。要重新阅读，请使用：

FileInputStream fis = new FileInputStream("C:\\Users\\Ganz\\Documents\\NetBeansProjects\\HotelObjects\\HotelObject.dat");
ObjectInputStream ois = new ObjectInputStream(fis);
Hotel hotel = (Hotel) ois.readObject();

Answer 3

ObjectOutputStream的输出意味着机器可读，因此它不一定是人类可读的。使用可关闭资源时，您应该在Java 1.7之前的try块中使用它们，并关闭该try的finally块中的资源，或者使用1.7+ try-with-resources语句。这是为了确保即使在抛出异常时资源也被关闭;

String path = "C:\\Users\\Ganz\\Documents\\NetBeansProjects\\HotelObjects\\HotelObject.dat";

try (FileInputStream fileInput = new FileInputStream(path); ObjectInputStream inputStream= new ObjectInputStream(fileInput)) {

    // Cast the Object returned from the stream to a Hotel object
    Hotel hotel = (Hotel) inputStream.readObject(); 

} catch (FileNotFoundException ex) {
   // TODO: Exception handling here   
} catch (IOException ex) {
   // TODO: Exception handling here     
}

如果您觉得默认的序列化表单不适合您的需要，那么您可以创建自己的。如果是这样，请查看如何创建自定义序列化表单。

用Java保存/加载对象数组

3 个答案: