Hibernate one-to-one mapping cautions

正確用法
@OneToOne(mappedBy = "post")
@JsonView(View.Detail.class)
private HotPost hotPost;

一開始犯傻
@OneToOne(mappedBy = "post")
@JsonView(View.Detail.class)
Set hotpost = new HashSet<>(0);
CautionsCautionsCautions
log只會說:Unknown mappedBy in: com.ws.pojo.Post.hotPost, referenced property unknown: java.util.Set.post


but @OneToMany
remember to use Set

ref:

http://www.mkyong.com/hibernate/hibernate-one-to-one-relationship-example-annotation/

http://viralpatel.net/blogs/hibernate-one-to-one-mapping-tutorial-using-annotation/

http://stackoverflow.com/questions/25756993/difference-between-one-to-one-vs-many-to-one-with-unique-true

http://www.tutorialspoint.com/hibernate/hibernate_one_to_one_mapping.htm

Hibernate batch process

 //in pojo (java bean)
      @BatchSize(size=5)
------------------------------------------------
      public void insertOldPost2HotPost() throws Exception{
       
       Session session = sessionFactory.getCurrentSession();

        @SuppressWarnings("unchecked")
        List posts = session.createQuery("from Post ").list();
        int itCount=0;
        for(Iterator it = posts.iterator(); it.hasNext(); ) {

            itCount++;

            Post post = (Post) it.next();

            HotPost hotPost = new HotPost(post);
            session.saveOrUpdate(hotPost);

            if (itCount % 5 == 0) {
            
                session.flush();
                session.clear();
            }
        }
    }

ref:

http://www.concretepage.com/hibernate/batch_size_hibernate_annotation

http://www.tutorialspoint.com/hibernate/hibernate_batch_processing.htm

Spring MVC @JsonView使用详解

     public class View {
      interface Summary {}
      interface SummaryWithDetail extends Summary{}
    }
    -----------------------------------
    public class User {
      @JsonView(View.Summary.class)
      private Long id;
      @JsonView(View.SummaryWithDetail.class)
      private String firstname;
    }
    -----------------------------------
    @RequestMapping("/user")［
    @JsonView(View.Summary.class)
    //or @JsonView(View.SummaryWithDetail.class)
    public List getUsers(){
     return userService.listUsers();
    }
    -----------------------------------
    result of @JsonView(View.Summary.class)
    [
     {
        "id": 70,
     }
    ]

    result of @JsonView(View.SummaryWithDetail.class)
    [
     {
        "id": 70,
        "firstname": 222
     }
    ]