Java GuessAnimal不会序列化

我已经在这方面做了很长时间了，不明白为什么它不能序列化我的数据。游戏是为了存储用户输入的问题和答案，当它得到它，所以下次游戏打开时，它将有这些问题提出。。。例如，动物会飞吗。。。不输入一个有助于我下次猜的问题。。。它不会飞。。它是什么？猴子。。。。好吧，下次游戏开始时。。。它会问自己是否会飞，是否是猴子。但问题是，我似乎无法把这些放在一起

如果我能很快得到帮助，我会非常感激。谢谢

//GuessTheAnimal Class-----------------------------------
 import javax.swing.JOptionPane;

import java.io.FileInputStream;
import java.io.ObjectInputStream;
import java.io.Serializable;
import java.io.ObjectOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;


public class GuessTheAnimal implements Serializable
{


public static void main(String[] args)
{
Tree animal = new Tree();
animal.instruction();
animal.play();
animal.writeToFile("treeData.ser");
Tree newAnimal = Tree.readFromFile("treeData.ser");
animal.play();



}

}

 //Tree Class-----------------------------------------
  import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
 import java.io.Serializable;

import javax.swing.JOptionPane;


    public class Tree
//Tree class
 {
private Node root;

//constructor
public Tree()
{   root = new Node();
    root.leftChild = new Node();
    root.rightChild = new Node();
    root.questionText = "Does it live on land?";
    root.leftChild.questionText ="bear";  // left side is Yes, right side is No
    root.rightChild.questionText = "parrot";
}

public void instruction()
{
    JOptionPane.showMessageDialog(null, "Think of an animal, I will try to guess it, answer yes or no");
}


public void play()
{
 Node current = root;
 Node parent = current;
 boolean isLeftChild = true;


 while(true)
 {   parent = current;
     int response = JOptionPane.showConfirmDialog(null,current.questionText );
     //code here for yes
     if (response == JOptionPane.YES_OPTION)
     {
        current = current.leftChild;
        isLeftChild=true;
     }
     //code here for no
     else if (response == JOptionPane.NO_OPTION)
     {
        current = current.rightChild;
        isLeftChild = false;
     }


     if (current.leftChild == null && current.rightChild == null)
     {
         int secondQ = JOptionPane.showConfirmDialog(null, "Is your animal a " + current.questionText + "?");

         if (secondQ == JOptionPane.YES_OPTION) 
         {
           JOptionPane.showMessageDialog(null,"I Guessed your animal!");
           return;
         }
         else if (secondQ == JOptionPane.NO_OPTION)
         {
             Node nodeOne = new Node();
             Node nodeTwo = new Node();

              nodeOne.questionText = JOptionPane.showInputDialog("Write a question that differentiates your animal from the animal I guessed, it would be yes for your animal");

              nodeTwo.questionText = JOptionPane.showInputDialog("What is this animal?");

              nodeOne.rightChild = current;
              nodeOne.leftChild = nodeTwo;

              // parent.leftChild = nodeOne or parent.rightChild = nodeOne
              if(isLeftChild == false)
              {
                  parent.rightChild = nodeOne;
                  System.out.println("right child");
              }
              else
                  {
                  parent.leftChild = nodeOne;
                  System.out.println("left Child");
                  }
              return;




         }


     }

}

}

public void preOrder(Node localRoot)
{
if(localRoot != null)
   {
   System.out.print(localRoot.questionText + " ");
   preOrder(localRoot.leftChild);
   preOrder(localRoot.rightChild);
   }
}

public Node getRoot(){
    return root;
}
public boolean writeToFile(String text) {
    try {
        FileOutputStream fileOut = new FileOutputStream("treeData.ser");
        ObjectOutputStream out = new ObjectOutputStream(fileOut);
        out.writeObject(root);
        out.close();
        fileOut.close();
        return true;
} catch (java.io.IOException e) {
    e.printStackTrace();
    System.out.println("-----problem in writeToFile()--------");
    return false;
}
}

/** @return tree read from file, if successful input, else null */
public static Tree readFromFile(String fileName) {
    try {
    FileInputStream fileIn = new FileInputStream("treeData.ser");
    ObjectInputStream objIn = new ObjectInputStream(fileIn);
    Tree newAnimal = (Tree) objIn.readObject();
    objIn.close();
    fileIn.close();
    return newAnimal;
    }
    catch (Exception e){//Catch exception if any
        e.printStackTrace();
        System.out.println("-----problem in readFromFile()--------");
    }
    return null;
}
}


 //Node Class----------------------------------


 public class Node {
 //Node class
//instance variables
public String questionText;
public Node leftChild;
public Node rightChild;

public void displayText()
{
    System.out.println(questionText);
}


/**
 * @param args
 */
public static void main(String[] args) {
    // TODO Auto-generated method stub

}

  }

---

如果要序列化一个对象，不仅该对象必须是可序列化的，而且它的所有子对象也必须是可序列化的。如果要序列化树，必须将树标记为可序列化。树的组件也必须是可序列化的类，等等，所以您还需要使节点也可序列化。我看不到Node类的声明，但这也将应用于它所持有的任何成员变量。

您再次调用的是

animal

，而不是您试图反序列化的实例

Tree animal = new Tree();
animal.instruction();
animal.play();
animal.writeToFile("treeData.ser");
Tree newAnimal = Tree.readFromFile("treeData.ser");
///should the following not be newAnimal?
animal.play();

---

好的，所以我是一个初学者——但你是说要在我所有的类中实现可序列化，然后我就应该被设置了？实际上我确实做了一些修改，它似乎正在编写，但它不会读回（崩溃）说java.lang.ClassCastException:Node不能在Tree.readFromFile（Tree.java:134）处强制转换到Tree在GuessTheAnimal.main（GuessTheAnimal.java:27）