Question

这是我的类Offer的代码，当我编译这部分代码时出现错误..请帮帮我。你的家伙

import java.io.Serializable;

public class Offer implements Comparable<Object>, Serializable {

    private static final long serialVersionUID = 1L;
    private Product product;
    private RegisteredUser user;
    private float amount;

    //stati dell'offerta
    private OfferState bestOffer;
    private OfferState overtakenOffer;
    private OfferState winnerOffer;
    private OfferState loserOffer;

    //stato attuale dell'offerta
    private OfferState state;

    public Offer(){}

    public Offer(Product product, RegisteredUser user, float amount)
    {
        this.user = user;
        this.amount = amount;
        this.product = product;

        bestOffer = new BestOffer(this);
        overtakenOffer = new OvertakenOffer(this);
        winnerOffer = new WinnerOffer(this);
        loserOffer = new LoserOffer(this);

        state = bestOffer;
    }


    public RegisteredUser getUser() {
        return user;
    }


    public float getAmount() {
        return amount;
    }


    public void setAmount(float amount) {
        this.amount = amount;
    }

    @Override
    public int compareTo(Object arg0) {

        return Float.compare(amount, ((Offer) arg0).getAmount());
    }


    public OfferState getBestOffer() {
        return bestOffer;
    }


    public OfferState getOvertakenOffer() {
        return overtakenOffer;
    }


    public OfferState getWinnerOffer() {
        return winnerOffer;
    }


    public OfferState getLoserOffer() {
        return loserOffer;
    }

    public OfferState getState() {
        return state;
    }

    public void setState(OfferState state) {
        this.state = state;
    }

    public void reciveOffer()
    {
        try
        {
            state.reciveOffer();
        }
        catch (UnsupportedOperationException e) {
        }
    }

    public void deadline()
    {
        try
        {
            state.deadline();
        }
        catch (UnsupportedOperationException e) {

        }
    }

    public Product getProduct() {
        return product;
    }

}

Error gwt

Answer 1

Product，RegisteredUser，OfferState等所有成员也必须可序列化或标记为瞬态。我认为他们不是你必须做的。这里有一个很好的例子： Serialization - readObject writeObject overrides

如何解决这种情况“没有可实例化的子类型”

1 个答案: