这是我的实体：
public class Account extends AbstractEntity<Long> {
@Id
@SequenceGenerator(name = "accountSequence",sequenceName = "SQ_ACCOUNTS",allocationSize = 1)
@GeneratedValue(strategy = GenerationType.SEQUENCE,generator = "accountSequence")
@Column(name = "ACC_ID",nullable = false)
private Long id;
...
}
public class Integration extends AbstractEntity<Long> {
@Id
@SequenceGenerator(name = "integrationSequence",sequenceName="SQ_INTEGRATIONS",generator = "integrationSequence")
@Column(name = "INT_ID",nullable = false)
private Long id;
...
public void addIntegration(Integration integration) {
IntegrationAccount association = new IntegrationAccount();
// This does not help
//association.setIntAccountsPK(new IntAccountsPK(integration.getId(),this.getId()));
association.setAccount(this);
association.setIntegration(integration);
this.integrationAccounts.add(association);
integration.getIntAccountsCollection().add(association);
}
}
这是连接表的实体
@Entity
@Table(name = "INT_ACCOUNTS")
public class IntegrationAccount {
@EmbeddedId
protected IntAccountsPK intAccountsPK;
@JoinColumn(name = "ACC_ID",referencedColumnName = "ACC_ID",insertable = false,updatable = false)
@ManyToOne
private Account account;
@JoinColumn(name = "INT_ID",referencedColumnName = "INT_ID",updatable = false)
@ManyToOne
private Integration integration;
...
}
@Embeddable
public class IntAccountsPK implements Serializable {
@Column(name = "INT_ID",nullable = false)
private Long intId;
@Column(name = "ACC_ID",nullable = false)
private Long accId;
...
}
当我这样做时：
account.addIntegrations(integrations.getTarget()); account.setCustomer(customer); accountService.save(account);
我在日志中得到了这个
引起：org.hibernate.id.IdentifierGenerationException：为以下项生成的null id：class com.dhl.dcc.domain.IntegrationAccount
我对这种映射没有太多的了解,请你告诉我如何改进这种映射(必须保留连接表的实体)以及如何使用相关的集成来保存帐户？谢谢.
解决方法
您可以为IntegrationAccount创建ID字段,然后为两个字段创建唯一约束.
@Entity
@Table(name = "INT_ACCOUNTS",uniqueConstraints=@UniqueConstraint(columnNames={"ACC_ID","INT_ID"}))
public class IntegrationAccount {
@Id
private Long id;
@JoinColumn(name = "ACC_ID",updatable = false)
@ManyToOne
private Integration integration;
...
}
奇迹般有效！