Java - 如何将 ArrayList 保存到文件中并打开它？

Question

我创建了一个名为“Subject”的类。该类由以下几行组成:

    class Subject {
    int serial;
    Double credit, gpa, tgpa = 0.0;

    public Subject(int serial, Double credit, Double gpa, Double tgpa) {
        this.serial = serial;
        this.credit = credit;
        this.gpa = gpa;
        this.tgpa = tgpa;
    }

    public int getSerial() {
        return serial;
    }

    public void setSerial(int serial) {
        this.serial = serial;
    }

    public Double getCredit() {
        return credit;
    }

    public void setCredit(Double credit) {
        this.credit = credit;
    }

    public Double getGpa() {
        return gpa;
    }

    public void setGpa(Double gpa) {
        this.gpa = gpa;
    }

    public Double getTgpa() {
        return tgpa;
    }

    public void setTgpa(Double tgpa) {
        this.tgpa = tgpa;
    }
}

我正在尝试创建两种方法将主题的 ArrayList 保存到文件中并将其作为主题的 ArrayList 重新打开。有什么解决办法吗？

Answer 1

您可以使用序列化和反序列化将其写入文件:

try (FileOutputStream fos = new FileOutputStream("serializedObject.txt"); 
     ObjectOutputStream oos = new ObjectOutputStream(fos)) {
      oos.writeObject(yourArrayList);
}

然后您可以再次读取并转换它:

ObjectInputStream ois =
                 new ObjectInputStream(new FileInputStream("serializedObject.txt"));
//Gets the object
ois.readObject();