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使用JPA/Hibernate時遇到了一個奇怪的問題。我在測試過程中看到重複的條目。使用休眠獲取重複條目
這裏是我的BaseEntity類：
@Entity
@Inheritance(strategy=InheritanceType.TABLE_PER_CLASS)
public abstract class BaseEntity {
@Id
@Column(name = "ID", updatable = false, nullable = false)
@GenericGenerator(name = "uniqueIDGenerator", strategy = "org.hibernate.id.enhanced.SequenceStyleGenerator", parameters = {
@org.hibernate.annotations.Parameter(name = "sequence_name", value = "ID_SEQUENCE"),
@org.hibernate.annotations.Parameter(name = "increment_size", value = "100"),
@org.hibernate.annotations.Parameter(name = "optimizer ", value = "pooled") })
@GeneratedValue(generator = "uniqueIDGenerator")
@NotNull
protected int id;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
}
這是我的主要合作伙伴等級：
@Entity
@Table(name = "partner")
public class Partner extends BaseEntity{
@Column(name = "name")
private String name;
@OneToMany(mappedBy="partner", fetch=FetchType.EAGER)
@Cascade(CascadeType.DELETE)
private List<Receipt> receipts;
@OneToMany(mappedBy="partner", fetch=FetchType.EAGER)
@Cascade(CascadeType.DELETE)
private List<Delivery> deliveries;
public Partner() {
setReceipts(new ArrayList<Receipt>());
setDeliveries(new ArrayList<Delivery>());
}
public Partner(String name){
this();
this.setName(name);
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public List<Receipt> getReceipts() {
return receipts;
}
public void setReceipts(List<Receipt> receipts) {
this.receipts = receipts;
}
public List<Delivery> getDeliveries() {
return deliveries;
}
public void setDeliveries(List<Delivery> deliveries) {
this.deliveries = deliveries;
}
}
合作伙伴有兩個子類，收據和交付。這是發票類：
@Entity
@Table(name = "receipt")
public class Receipt extends BaseEntity{
@ManyToOne(fetch=FetchType.LAZY)
@JoinColumn(name="partnerId")
private Partner partner;
@Column(name = "name")
private String name;
@Column(name = "json")
private String json;
@Transient
private ReceiptContainer receiptContainer;
public Receipt() {
}
public Receipt(String name){
this();
this.setName(name);
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getJson() {
return json;
}
public void setJson(String json) {
this.json = json;
}
public ReceiptContainer getReceiptContainer() {
return receiptContainer;
}
public void setReceiptContainer(ReceiptContainer receiptContainer) {
this.receiptContainer = receiptContainer;
}
public Partner getPartner() {
return partner;
}
public void setPartner(Partner partner) {
this.partner = partner;
}
}
這裏是交貨類：
@Entity
@Table(name = "delivery")
public class Delivery extends BaseEntity{
@ManyToOne(fetch=FetchType.LAZY)
@JoinColumn(name="partnerId")
private Partner partner;
@Column(name = "name")
private String name;
@Column(name = "json")
private String json;
@Transient
private DeliveryContainer deliveryContainer;
public Delivery() {
}
public Delivery(String name){
this();
this.setName(name);
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getJson() {
return json;
}
public void setJson(String json) {
this.json = json;
}
public DeliveryContainer getDeliveryContainer() {
return deliveryContainer;
}
public void setDeliveryContainer(DeliveryContainer deliveryContainer) {
this.deliveryContainer = deliveryContainer;
}
public Partner getPartner() {
return partner;
}
public void setPartner(Partner partner) {
this.partner = partner;
}
}
我收到我的對象是這樣的：
@Transactional
public Partner get(int id){
Partner partner = entityManager.find(Partner.class, id);
return partner;
}
正如你可以看到，夥伴類包括對象列表和對象列表，它們分別存儲在它們自己的表格，收據和傳送中。
---我再往前走之前，我想指出的是項目的正確號碼顯示在數據庫中。只有在我的Java應用程序.---獲取對象時出現此問題
當我添加一個對象，沒有對象都存在，則顯示一個對象，並沒有顯示任何對象，預計。如果存在一個對象和一個對象，則再次顯示一個對象和一個對象，這是預期的。如果存在多個對象或對象，則會出現該問題。例如，如果添加兩個對象，但只添加一個對象，則會顯示兩個對象和兩個對象。
爲了更好地說明這一點，請參閱下面我的測試情況表。意外的結果被用破折號包圍。
<Receipt> Obj Added | <Delivery> Obj Added | <Receipt> Obj Displayed | <Delivery> Obj Displayed
0 | 0 | 0 | 0
0 | 1 | 0 | 1
1 | 0 | 1 | 0
1 | 1 | 1 | 1
1 | 2 | ---2--- | ---2---
2 | 1 | ---2--- | ---2---
2 | 2 | ---4--- | ---4---
我的問題是，爲什麼我看到這些意外的結果？
需要幾個信息來幫助：顯示你如何爲這些類生成ID（發佈你的baseentity類），顯示你如何持久化和檢索數據 – zmf 2014-11-05 17:23:53
剛剛添加，謝謝 – user1472409 2014-11-05 17:45:54