【发布时间】：2019-11-13 12:58:01
【问题描述】：
我遇到了一个非常烦人的问题，即在对象合并到 EntityManager 后实体会丢失其状态。
在应用程序中有一个带有 ExpenditureStatements 的“档案”，其中包含许多支出。
这些支出可以（部分）向多个债务人索赔。 为 ExpenditureStatement 创建一个 ExpenditureStatementClaim。 为 ExpenditureStatement 上的每个 Expenditure 创建一个 ExpenditureClaim。
ExpenditureClaim 和 ExpenditureStatementClaim 都被保留，没有任何问题。 然而，在调用 entitymanager 上的合并后，支出会失去其状态： em.merge（档案）。
但是，每个支出中的数据都会恢复到数据库中的最后一个状态。
我已经尝试过仅从上到下级联，我已经对 equals/hashcode 进行了更改，但这并没有改变任何内容。
是否有人知道可能导致此问题的原因？
档案：
@Entity
@Table(name = "DOSSIER")
@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
@DiscriminatorColumn(name = "DOSSIER_TYPE", discriminatorType = DiscriminatorType.STRING, length = 48)
public abstract class Dossier {
@OneToMany(mappedBy = ExpenditureStatement.PROP_DOSSIER, cascade = CascadeType.ALL, orphanRemoval = true, fetch = FetchType.LAZY)
private List<ExpenditureStatement> expenditureStatements = new ArrayList<ExpenditureStatement>();
}
支出报表：
@Entity
@Table(name = "EXPENDITURE_STATEMENT")
public class ExpenditureStatement {
@ManyToOne(fetch = FetchType.LAZY, cascade = {CascadeType.MERGE})
@JoinColumn(name = "DOSSIER_ID", nullable = false)
private Dossier dossier;
@OneToMany(mappedBy = Expenditure.PROP_EXPENDITURE_STATEMENT, cascade = CascadeType.ALL, orphanRemoval = true, fetch = FetchType.EAGER)
private List<Expenditure> expenditures = new ArrayList<Expenditure>();
@OneToMany(mappedBy = ExpenditureStatementClaim.PROP_EXPENDITURE_STATEMENT, cascade = CascadeType.ALL, orphanRemoval = true, fetch = FetchType.EAGER)
private Collection<ExpenditureStatementClaim> expenditureStatementClaims = new ArrayList<ExpenditureStatementClaim>();
}
支出：
@Entity
@Table(name = "EXPENDITURE")
@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
@DiscriminatorColumn(name = "EXPENDITURE_ORIGIN_CD", discriminatorType = DiscriminatorType.STRING, length = 48)
public abstract class Expenditure extends EntityObject<Long> {
@ManyToOne(fetch = FetchType.EAGER, cascade = {CascadeType.PERSIST, CascadeType.MERGE})
@JoinColumn(name = "EXPENDITURE_STATEMENT_ID", nullable = false)
private ExpenditureStatement expenditureStatement;
@OneToMany(mappedBy = ExpenditureClaim.PROP_EXPENDITURE, cascade = CascadeType.ALL, orphanRemoval = true, fetch = FetchType.EAGER)
private Collection<ExpenditureClaim> claims = new HashSet<>();
@NotNull
@Column(name = "EXPENDITURE_STATUS_CD", nullable = false)
@Enumerated(EnumType.STRING)
private ExpenditureStatus status;
public abstract BigDecimal getAmount();
}
ExpenditureStatementClaim：
@Entity
@Table(name = "DEEL_STAAT")
public class ExpenditureStatementClaim {
@NotNull
@ManyToOne(cascade = {CascadeType.MERGE, CascadeType.PERSIST})
@JoinColumn(name = "EXPENDITURE_STATEMENT_ID", nullable = false)
private ExpenditureStatement expenditureStatement;
@OneToMany(mappedBy = ExpenditureClaim.PROP_EXPENDITURE_STATEMENT_CLAIM, cascade = CascadeType.ALL, orphanRemoval = true, fetch = FetchType.EAGER)
private Collection<ExpenditureClaim> expenditureClaims = new ArrayList<>();
@ManyToOne(cascade=CascadeType.ALL)
@JoinColumn(name = "INVOICE_ID")
private Invoice invoice;
}
ExpenditureClaim：
@Entity
@Table(name = "EXPENDITURE_CLAIM")
public class ExpenditureClaim extends EntityObject<Long> {
@ManyToOne(fetch = FetchType.EAGER, cascade = {CascadeType.PERSIST, CascadeType.MERGE})
@JoinColumn(name = "EXPENDITURE_ID", nullable = false)
private Expenditure expenditure;
@Column(name = "AMOUNT", precision = NumberConstants.CURRENCY_PRECISION, scale = NumberConstants.CURRENCY_OPERATION_SCALE)
private BigDecimal amount;
@ManyToOne(fetch = FetchType.EAGER, cascade = {CascadeType.PERSIST, CascadeType.MERGE})
@JoinColumn(name = "EXPENDITURE_ST_CLAIM_ID", nullable = false)
private ExpenditureStatementClaim expenditureStatementClaim;
}
【问题讨论】：
-
您有两个分支引用同一个 ExpenditureClaim 类 - 这两个分支中的对象是否相同？由于它们具有对 Expenditure 的引用，因此请检查这些实例是否与您正在查看的相同，并且是否具有您想要合并到数据库中的状态更改以及 ExpenditureStatement 实例引用的那些。您如何读取它们以进行修改可能是问题的一部分 - 检查它们是否是图表两个分支中相同数据的相同实例。
标签： java jpa eclipselink persistence entitymanager