Question

当我尝试在简单的DataGrid中加载“Product”列表时出现此错误：

Didn't receive an acknowledge message
Was expecting mx.messaging.messages.AcknowledgeMessage, but received null

经过多次测试后，我很确定这是一个映射问题，因为我不习惯注释，也许它来自这里，这里是我的课程：

Product.java：

@Entity
@Table(name="product")
public class Product implements Serializable
{
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name="product_id")
    private long productId;

    private String name;

    @ManyToOne(optional = false, fetch = FetchType.EAGER)
    @JoinColumn(name="category_id")
    private Category category;

    @OneToMany(mappedBy = "product", cascade = CascadeType.ALL, fetch = FetchType.LAZY)
    private Collection<Buy> clients;

    ...Getters & Setters...
}

Client.java

@Entity
@Table(name="client")
public class Client implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name="client_id")
    private long clientId;

    private String name;

    @OneToMany(mappedBy = "client", cascade = CascadeType.ALL, fetch = FetchType.LAZY)
    private Collection<Buy> products;

    public long getClientId() {
        return clientId;
    }

    public void setClientId(long clientId) {
        this.clientId = clientId;
    }

    ...Getters & Setters...
}

Buy.java

@Entity
@Table(name="buy")
public class Buy implements Serializable
{
    @EmbeddedId
    private BuyId buyId;

    @ManyToOne
    @PrimaryKeyJoinColumn(name="product_id", referencedColumnName="product_id")
    private Product product;

    @ManyToOne
    @PrimaryKeyJoinColumn(name="client_id", referencedColumnName="client_id")
    private Client client;

    @Temporal(value = TemporalType.DATE)
    private Date date;

    ...Getters & Setters...
}

BuyId.java

public class BuyId implements Serializable
{
    private long clientId;

    private long productId;

    ...Getters & Setters...
}

类别并不重要，因为只有Id和Name，Product和Category之间的关联是单向的，真正的问题是当我尝试从数据库中检索我的产品时，这个错误发生了，就像我说的，我几乎可以肯定它来自映射/注释错误......

感谢。

Answer 1

问题是您可能不会在Flex应用程序的任何位置引用类Buy.as，因此Flex编译器不会将其包含在swf中，从而在反序列化期间导致此ArgumentError。检查这个的一种快速方法是在mxml中添加一个虚拟变量： private static var dummy：Buy = null;

您会找到更详细的解释here。

[Flex] [GraniteDS] Flex端错误：未收到确认消息

1 个答案: