Question

我试图在项目中第一次使用JPA。我的大多数实体工作正常，但我遇到了一个加入继承策略的问题。实体也被杰克逊序列化，所以他们也有Json注释。

父母＆＃34;用户＆＃34;类：（编辑：添加＆＃34;输入＆＃34;字段）

@JsonTypeInfo(use=JsonTypeInfo.Id.NAME, include= JsonTypeInfo.As.WRAPPER_OBJECT)
@JsonTypeName("user")
@JsonSubTypes({
        @JsonSubTypes.Type(name="customer", value=Customer.class),
        @JsonSubTypes.Type(name="employee", value=Employee.class)})
@Entity(name = "User")
@Table(name="user")
@Inheritance(strategy = InheritanceType.JOINED)
@DiscriminatorColumn(name="type",discriminatorType = DiscriminatorType.INTEGER)
@NamedQuery(name="User.all",query = "select u from User u")
public abstract class User {

    @Id
    private String username;
    @Column(name = "type",nullable = false)
    private int type;

    public User(){

    }

    public int getType() {
        return type;
    }

    public void setType(int type) {
        this.type = type;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public abstract Set<Order> getOrders();
}

儿童＆＃34;员工＆＃34;

@JsonTypeName("employee")
@Entity(name="Employee")
@Table(name="employee")
@PrimaryKeyJoinColumn(name = "username",referencedColumnName = "username")
@DiscriminatorValue("1")
@NamedQuery(name = "Employee.all",query = "select e from Employee e")
public class Employee extends User implements Serializable{

    private String username;
    private String firstName;
    private String lastName;
    private String email;
    @Convert(converter = LocalDatePersistenceConverter.class)
    private LocalDate dateStarted;
    @Convert(converter = LocalDatePersistenceConverter.class)
    private LocalDate dateEnded;

    @OneToMany(mappedBy = "employee",targetEntity = Order.class,fetch = FetchType.EAGER,cascade = CascadeType.PERSIST)
    @JsonIgnore
    private Set<Order> orders = new HashSet<>();

    public Employee() {

    }

    @Override
    public Set<Order> getOrders() {
        return orders;
    }

    public void setOrders(Set<Order> orders) {
        this.orders = orders;
    }

    public void addOrder(Order order){
        orders.add(order);
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getFirstName() {
        return firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public String getEmail() {
        return email;
    }

    public String getDateStarted() {
        if(dateStarted != null)
            return dateStarted.toString();
        else return null;
    }

    public void setDateStarted(LocalDate dateStarted) {
        this.dateStarted = dateStarted;
    }

    public String getDateEnded() {
        if(dateEnded != null)
            return dateEnded.toString();
        else return null;
    }

    public void setDateEnded(LocalDate dateEnded) {
        this.dateEnded = dateEnded;
    }

    @Override
    public String toString(){
        return getUsername();
    }
}

小孩＆＃34;顾客＆＃34;：（编辑：删除@Id字段）

@JsonTypeName("customer")
@Entity(name="Customer")
@Table(name="customer")
@PrimaryKeyJoinColumn(name = "username",referencedColumnName = "username")
@DiscriminatorValue("2")
@NamedQueries({
        @NamedQuery(name="Customer.all",query = "select c from Customer c")
})
public class Customer extends User implements Serializable{

    public enum VIP_TYPE {NORMAL,SILVER,GOLD,DIAMOND}

    @Transient
    private static final int SILVER_THRESHOLD = 1000;
    @Transient
    private static final int GOLD_THRESHOLD = 2000;
    @Transient
    private static final int DIAMOND_THRESHOLD = 3000;

    private String firstName;
    private String lastName;
    private String email;
    private String address;
    private String postcode;
    private String mobileNumber;
    private String homeNumber;
    @Convert(converter = VipTypeConverter.class)
    private VIP_TYPE vipGroup;
    private String discount;

    @OneToMany(mappedBy = "customer",targetEntity = Order.class,fetch=FetchType.EAGER,cascade = CascadeType.ALL)
    @JsonIgnore
    private Set<Order> orders = new HashSet<>();

    public Customer() {
    }

    @Override
    public Set<Order> getOrders() {
        return orders;
    }

    public void setOrders(Set<Order> orders) {
        this.orders = orders;
    }

    public void addOrder(final Order order){
        orders.add(order);
        updateVipGroup();
    }

    private void updateVipGroup() {
        int sum = orders.stream().map(Order::getPayment).distinct().mapToInt(p->p.getAmmount()).sum();
        if(sum > DIAMOND_THRESHOLD){
            vipGroup = VIP_TYPE.DIAMOND;
            return;
        }
        if(sum > GOLD_THRESHOLD){
            vipGroup = VIP_TYPE.GOLD;
            return;
        }
        if(sum > SILVER_THRESHOLD){
            vipGroup = VIP_TYPE.SILVER;
            return;
        }
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public void setDiscount(String discount) {
        this.discount = discount;
    }

    public void setVipGroup(VIP_TYPE vipGroup) {
        this.vipGroup = vipGroup;
    }

    public void setHomeNumber(String homeNumber) {
        this.homeNumber = homeNumber;
    }

    public void setMobileNumber(String mobileNumber) {
        this.mobileNumber = mobileNumber;
    }

    public void setPostcode(String postcode) {
        this.postcode = postcode;
    }

    public String getDiscount() {
        return discount;
    }

    public VIP_TYPE getVipGroup() {
        return vipGroup;
    }

    public String getFirstName() {
        return firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public String getEmail() {
        return email;
    }

    public String getAddress() {
        return address;
    }

    public String getPostcode() {
        return postcode;
    }

    public String getMobileNumber() {
        return mobileNumber;
    }

    public String getHomeNumber() {
        return homeNumber;
    }

}

的persistence.xml

<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence">
    <persistence-unit name="local" transaction-type="JTA">
        <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
        <jta-data-source>jdbc/cod</jta-data-source>
        <class>com.technicalpioneers.cod.user.Customer</class>
        <class>com.technicalpioneers.cod.user.Employee</class>
        <class>com.technicalpioneers.cod.user.User</class>
        <exclude-unlisted-classes>false</exclude-unlisted-classes>
    </persistence-unit>
</persistence>

所有与＆＃34;员工＆＃34;工作文件，我可以使用命名查询Employee.all来查找数据库中的所有员工。

但是，如果我尝试检索任何客户，我会收到错误。如果我尝试运行命名查询Customer.all，我会得到：

java.lang.IllegalArgumentException: NamedQuery of name: Customer.all not found.

如果我尝试使用EntityManager的find（）方法找到我得到的特定客户：

javax.servlet.ServletException: Exception [EclipseLink-43] (Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd): org.eclipse.persistence.exceptions.DescriptorException
Exception Description: Missing class for indicator field value [2] of type [class java.lang.Integer].
Descriptor: RelationalDescriptor(com.technicalpioneers.cod.user.User --> [DatabaseTable(user)])

我不明白为什么JPA找不到客户实体。我已经检查了用户表和＆＃34;类型＆＃34;列是正确的数字，并正确设置@DescriminatorValue。它几乎就像注释被忽略了一样？

做了很多干净的重建并重新组装。非常感谢任何帮助！

Answer 1

我最终发现了这一点。 https://bugs.eclipse.org/bugs/show_bug.cgi?id=429992 事实证明，EclipseLink将默默地忽略具有lambda表达式的实体！非常讨厌，至少在日志中没有提到它！

感谢所有花时间的人！

JPA实体被忽略

1 个答案: