java - Hibernate:手动调用 SequenceGenerator？

Question

我已经编写了自己的 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 ...
   }
}

有谁知道我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")

我将非常感谢任何解决方案!!!!

非常感谢，诺伯特

Answer 1

您可以轻松地从您的生成器类中调用 SequenceGenerator。通过编写这段代码。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 是应该创建的序列名称。在数据库中通过拧 create sequence Stud_NoSequence;Hibernate.String 是 SequenceGenerator 类将返回的类型。

领域类将是

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;
}
    }