JPA - 在具有公共超类的 2 个不同实体之间复制数据

Question

我有这样的情况

@MappedSuperclass
public class BaseEntity {

   @Column(name = "COL_1)
   private String column1;

   @Column(name = "COL_2)
   private String column2;
}

@Entity
@Table(name = "TABLE_A")
public class EntityA extends BaseEntity {
   @Id
   private Long idA;
}

@Entity
@Table(name = "TABLE_B")
public class EntityB extends BaseEntity {
   @Id
   private Long idB;
}

有一个 EntityA 的实例，我想要的是创建一个 EntityB 的新实例，其中所有属性都从 [=11= 的实例继承自超类 "copied" ], 除了 EntityB 个特定的。

有一种 "smart" 方法可以做到这一点，而不需要每个人都做 set/get?

N.B。上面的代码只是一个例子，在我的真实案例中，超类有超过 100 个属性...

Answer 1

Apache Beanutils 库具有这样的功能。

https://commons.apache.org/proper/commons-beanutils/apidocs/org/apache/commons/beanutils/BeanUtils.html#copyProperties-java.lang.Object-java.lang.Object-

package test;

import java.lang.reflect.InvocationTargetException;
import org.apache.commons.beanutils.BeanUtils;

...
EntityA instanceA = ...
EntityB instanceB = ...
BeanUtils.copyProperties(instanceB, instanceA);
  // exceptions are thrown when some negative situation occur.
  // I have no knowledge r/o property (having only getter) is not set / thow exception

  //You should review, how this automatic task is executed in Your scenario. But it is auto 

...persist(instanceB);