Java Eclipse中的序列化器()方法“构造函数序列化器()未定义”

public class MyClass implements Serializable {
    // 类的成员变量和方法
}

MyClass obj = new MyClass();
try {
    FileOutputStream fileOut = new FileOutputStream("object.ser");
    ObjectOutputStream out = new ObjectOutputStream(fileOut);
    out.writeObject(obj);
    out.close();
    fileOut.close();
} catch (IOException e) {
    e.printStackTrace();
}

MyClass obj = null;
try {
    FileInputStream fileIn = new FileInputStream("object.ser");
    ObjectInputStream in = new ObjectInputStream(fileIn);
    obj = (MyClass) in.readObject();
    in.close();
    fileIn.close();
} catch (IOException | ClassNotFoundException e) {
    e.printStackTrace();
}