Question

我写了自己的IdGenerator：

public class AkteIdGenerator implements IdentifierGenerator {
   public Serializable generate(SessionImplementor session, Object object)
         throws HibernateException {
      // if custom id is set -> use this id
      if (object instanceof SomeBean) {
         SomeBean someBean = (SomeBean) object;
         Long customId = someBean.getCustomId();
         if (customId != 0) {
            return customId;
         }
      }
      // otherwise --> call the SequenceGenerator manually
      SequenceStyleGenerator sequenceGenerator ...
   }
}

有谁知道如何从我的生成器类调用sequenceGenerator，我通常可以根据注释定义：

@GeneratedValue(
        strategy = GenerationType.SEQUENCE,
        generator = "MY_SEQUENCE")
@SequenceGenerator(
        allocationSize = 1,
        name = "MY_SEQUENCE",
        sequenceName = "MY_SEQUENCE_NAME")

我会非常感谢任何解决方案!!!!

非常感谢，Norbert

Answer 1

您可以通过Generator类调用SequenceGenerator。通过编写此代码。自定义生成器类应该是

 public class StudentNoGenerator implements IdentifierGenerator {

public Serializable generate(SessionImplementor session, Object object)throws HibernateException {

    SequenceGenerator generator=new SequenceGenerator();
    Properties properties=new Properties();
    properties.put("sequence","Stud_NoSequence");
    generator.configure(Hibernate.STRING, properties, session.getFactory().getDialect());
    return generator.generate(session, session);

}

}
在上面的代码中，Stud_NoSequence是可以创建的序列名称。在数据库中通过wring create sequence Stud_NoSequence; Hibernate.String是SequenceGenerator类将返回的类型。

，域类将是

import javax.persistence.Column;
    import javax.persistence.Entity;
    import javax.persistence.GeneratedValue;
    import javax.persistence.Id;
    @Entity
    @org.hibernate.annotations.GenericGenerator(
    name = "Custom-generator",
    strategy = "com.ssis.id.StudentNoGenerator"
    )
    public class Student {
@Id @GeneratedValue(generator = "Custom-generator")
String rno;
@Column
String name;
public String getRno() {
    return rno;
}
public void setRno(String rno) {
    this.rno = rno;
}
public String getName() {
    return name;
}
public void setName(String name) {
    this.name = name;
}
    }

Answer 2

  @Id
  @GenericGenerator(name = "seq_id", strategy = "de.generator.AkteIdGenerator")
  @GeneratedValue(generator = "seq_id")
  @Column(name = "ID")
  private Integer Id;

http://blog.anorakgirl.co.uk/2009/01/custom-hibernate-sequence-generator-for-id-field/

Answer 3

不确定这是否有帮助，但是我在寻找答案的过程中一直遇到这篇文章，尽管找不到答案，但我自己找到了解决方案。所以我认为这可能是最好的分享场所。

如果您将休眠用作JPA提供程序，则可以手动调用分配给给定实体类的ID生成器。首先注入JpaContext：

@Autowired
org.springframework.data.jpa.repository.JpaContext jpaContext;

然后使用以下命令获取内部的org.hibernate.id.IdentifierGenerator：

org.hibernate.engine.spi.SessionImplementor session = jpaContext.getEntityManagerByManagedType(MyEntity.class).unwrap(org.hibernate.engine.spi.SessionImplementor.class);
org.hibernate.id.IdentifierGenerator generator = session.getEntityPersister(null, new MyEntity()).getIdentifierGenerator();

现在您可以通过编程方式从生成器获取ID：

Serializable id = generator.generate(session, new MyEntity());

Answer 4

您的帖子有助于更新序列的名称。

因为我每月使用一个序列，并且配置不会更新每个标识符生成。

这是我的代码：

@Override
public Serializable generate(SessionImplementor sessionImplementator,
        Object object) throws HibernateException {
    Calendar now = Calendar.getInstance();
    // If month sequence is wrong, then reconfigure.
    if (now.get(Calendar.MONTH) != SEQUENCE_DATE.get(Calendar.MONTH)) {
        super.configure(new LongType(), new Properties(),
                sessionImplementator.getFactory().getDialect());
    }
    Long id = (Long) super.generate(sessionImplementator, object);
    String sId = String.format("%1$ty%1$tm%2$06d", SEQUENCE_DATE, id);
    return Long.parseLong(sId);// 1301000001
}

Hibernate：手动调用SequenceGenerator？

4 个答案: