@ManyToOne配置延迟加载,如果是关联主键列,
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "billid", insertable = false,updatable = false, nullable = false)
private Bill bill ;
@Setter
@Getter
@Entity
@DynamicUpdate
@Table(name = "Bill")
public class Bill implements Serializable {
/**
* 主键
*/
@Id
@Column(name = "ID")
private String id;
@Column(name = "SID")
private String sid;
}
延迟加载是正常的。
但如果关联的Address的是sid而不是id的话,就延时加载就有问题。如下代码:
@ManyToOne(fetch = FetchType.LAZY) @JoinColumn(name = "billid", referencedColumnName = "sid", insertable = false,updatable = false, nullable = false) private Bill bill;
这时的解决方案,需要了解PersistentAttributeInterceptable的机制。
@DynamicUpdate
@Entity
@Setter
@Getter
@Table ( name ="BillDETAIL" )
public class BillDetail implements PersistentAttributeInterceptable, Serializable {
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "billid", referencedColumnName = "sid", insertable = false,updatable = false, nullable = false)
@LazyToOne(LazyToOneOption.NO_PROXY)
private Bill bill;
public Bill getBill() {
if (interceptor!=null) {
return (Bill)interceptor.readObject(this, "bill", bill);
}
return bill;
}
public void setBill(BillView bill) {
if (interceptor!=null) {
this.billView = (Bill) interceptor.writeObject(this,"owner", this.bill,bill);
return ;
}
this.bill = bill;
}
@Transient
private PersistentAttributeInterceptor interceptor;
@Override
public PersistentAttributeInterceptor $$_hibernate_getInterceptor() {
return interceptor;
}
@Override
public void $$_hibernate_setInterceptor(PersistentAttributeInterceptor interceptor) {
this.interceptor = interceptor;
}
}
参考:
https://blog.csdn.net/johnf_nash/article/details/86557107
https://blog.csdn.net/windsigirl123/article/details/60957632