反序列化多个Java对象 [英] Deserialize multiple Java Objects

问题描述

亲爱的同事们，

我有一个Garden类，我在其中序列化和反序列化多个Plant类对象。序列化工作正常，但是如果想要在mein静态方法中将其分配给调用变量，则反序列化不起作用。

I have a Garden class in which I serialize and deserialize multiple Plant class objects. The serializing is working but the deserializing is not working if a want to assign it to calling variable in the mein static method.

public void searilizePlant(ArrayList<Plant> _plants) {
    try {
        FileOutputStream fileOut = new FileOutputStream(fileName);
        ObjectOutputStream out = new ObjectOutputStream(fileOut);
        for (int i = 0; i < _plants.size(); i++) {
            out.writeObject(_plants.get(i));
        }
        out.close();
        fileOut.close();
    } catch (IOException ex) {
    }
}

反序列化代码：

public ArrayList<Plant> desearilizePlant() {
    ArrayList<Plant> plants = new ArrayList<Plant>();
    Plant _plant = null;
    try {
        ObjectInputStream in = new ObjectInputStream(new FileInputStream(fileName));
        Object object = in.readObject();

       // _plant = (Plant) object;


        // TODO: ITERATE OVER THE WHOLE STREAM
        while (object != null) {
            plants.add((Plant) object);
            object = in.readObject();
        }

        in.close();
    } catch (IOException i) {
        return null;
    } catch (ClassNotFoundException c) {
        System.out.println("Employee class not found");
        return null;
    }
    return plants;
}

我的调用代码：

ArrayList<Plant> plants = new ArrayList<Plant>();
plants.add(plant1);
Garden garden = new Garden();
garden.searilizePlant(plants);

// THIS IS THE PROBLEM HERE
ArrayList<Plant> dp = new ArrayList<Plant>();
dp = garden.desearilizePlant();

编辑

我得到一个空指针异常

@NilsH的解决方案工作正常，谢谢！

edit
I got a null Pointer exception
The solution of @NilsH is working fine, thanks!

推荐答案

如何序列化整个列表而不是？无需序列化列表中的每个单独对象。

How about serializing the entire list instead? There's no need to serialize each individual object in a list.

public void searilizePlant(ArrayList<Plant> _plants) {
    try {
        FileOutputStream fileOut = new FileOutputStream(fileName);
        ObjectOutputStream out = new ObjectOutputStream(fileOut);
        out.writeObject(_plants);
        out.close();
        fileOut.close();
    } catch (IOException ex) {
    }
}

public List<Plant> deserializePlant() {
    List<Plants> plants = null;
    try {
        ObjectInputStream in = new ObjectInputStream(new FileInputStream(fileName));
        plants = in.readObject(); 
        in.close();
    }
    catch(Exception e) {}
    return plants;
}

如果这不能解决您的问题，请发布有关您的错误的更多详细信息。

If that does not solve your problem, please post more details about your error.

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