##UUID

@Id    @Type(type = "org.hibernate.type.PostgresUUIDType")    private UUID id = UUID.randomUUID();

##dao

public interface DemoDao extends JpaRepository
    
      {    public Demo findById(UUID uuid);}
    

##使用

Demo demo =demoDao.findById(UUID.fromString("127757ac-571c-9052-cdd9-a31f91d15972"));