public class User implements Serializable{ public String name; public String surname; public List<Picked> pickedBooks = new ArrayList<>(); // Code omitted. }
然后去上课:
public class Picked { public Book book; public int period; public int cost; // Code omitted. }
和班级书:
public class Book { public String name; public String bookTitle; public int howMany; // Code omitted. }
所以在主要的我创建新用户并序列化它:
User user = new User(); user.setName("John"); user.setSurname("James"); String fileName = "data.bin"; try (ObjectOutputStream os = new ObjectOutputStream(new FileOutputStream(fileName))) { os.writeObject(user); } catch (IOException ex) { Logger.getLogger(Library.class.getName()).log(Level.SEVERE,null,ex); }
一切都很完美,但如果我这样做的话:
Book book = new Book("Dan brown","Angels and Demons",1); Picked pck = new Picked(book,20,2); user.add(pck);
java.io.NotSerializableException:
at
java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1183)
at
java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:347)
at java.util.ArrayList.writeObject(ArrayList.java:742) at
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606) at
java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:988)
at
java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1495)
at
java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1431)
at
java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1177)
at
java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1547)
at
java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1508)
at
java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1431)
at
java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1177)
at
java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:347)