当我尝试创建四个客户时,有代码。 1.将Customer1,2写入数据库 2. 合并Customer3(具有相同的id,例如1) 3.合并Customer4(再次具有相同的id) 我想创建同一实体的任何版本
所以,
public static void main(String[] args) {
EntityManagerFactory entityManagerFactory = Persistence.createEntityManagerFactory("Info");
EntityManager entityManager = entityManagerFactory.createEntityManager();
Customer customer1 = new Customer("1", "Vladislav");
Customer customer2 = new Customer("2", "Maria");
Customer customer3 = new Customer("1", "Ekaterina");
Customer customer4 = new Customer("1", "Helen");
entityManager.getTransaction().begin();
entityManager.persist(customer1);
entityManager.persist(customer2);
entityManager.getTransaction().commit();
entityManager.getTransaction().begin();
entityManager.merge(customer3);
entityManager.getTransaction().commit();
entityManager.getTransaction().begin();
entityManager.merge(customer4);
entityManager.getTransaction().commit();
//get versions here:
entityManager = entityManagerFactory.createEntityManager();
AuditReader auditReader = AuditReaderFactory.get(entityManager);
List<Number> versions = auditReader.getRevisions(Customer.class, "1");
System.out.println("========");
System.out.println(Arrays.toString(versions.toArray()));
entityManager.close();
entityManagerFactory.close();
}
客户实体:
package entity;
import lombok.AllArgsConstructor;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;
import org.hibernate.envers.Audited;
import javax.persistence.*;
@Getter
@Setter
@NoArgsConstructor
@Entity
@Audited
public class Customer {
@Id
@Column(length = 100, nullable = false)
private String id;
private String name;
@Version
int version;
public Customer(String id, String name) {
this.id = id;
this.name = name;
}
@Override
public String toString() {
return "Customer{" +
"id='" + id + '\'' +
", name='" + name + '\'' +
", version=" + version +
'}';
}
}
当我仅保留客户 1,2 并合并客户 3 时 - 一切正常。
但是在我添加与 customer4 实体的合并时 - 出现错误消息 -
线程“main”中出现异常 javax.persistence.OptimisticLockException:行已被另一个事务更新或删除(或未保存值映射不正确):[entity.Customer#1] 导致:org.hibernate.StaleObjectStateException:行已被另一个事务更新或删除(或未保存值映射不正确):[entity.Customer#1] ... 2 更多
为什么我每次都无法合并?
最佳答案
您只能将客户与具有最新版本的实例合并。
customer1
具有版本=0
id = '1'的当前版本现在为 0
customer3
具有 version=0,因此可以合并,合并后 version=1。
id = '1'的当前版本现在是 1
customer4
具有 version=0,因此无法再进行合并。
关于java - Jpa 合并抛出 StaleObjectStateException?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/53078560/