persistence

Hibernate is a persistence framework which is used to persist data from Java environment to database. I am so confused, if we persist and object to a database, then why does Hibernate architecture indicate the persistent object in the middle of Application and Hibernate in picture? (source: viralpatel.net ) DarkHorse I will make it more clearer. Persistent objects are instances of POJO classes that you create that represent rows in the table in the database. According to hibernate-doc an instance of POJO class representing table in database goes through 3 states of which persistent is one of

I'm working on an open source project dealing with adding metadata to folders. The provided (Python) API lets you browse and access metadata like it was just another folder. Because it is just another folder. \folder\.meta\folder\somedata.json Then I came across HDF5 and its derivation Alembic . Reading up on HDF5 in the book Python and HDF5 I was looking for benefits to using it compared to using files in folders, but most of what I came across spoke about the benefits of a hierarchical file-format in terms of its simplicity in adding data via its API: >>> import h5py >>> f = h5py.File(

I am developing a BlackBerry application. I want to store the details of multiple users in my mobile. I have to store data like username, first name, last name ,email id ,phone number for each user. Can any one please provide me a sample code for persistent store using which I can store all this data in a vector and retrieve later. This link should answer most of what you need to know - http://www.miamicoder.com/post/2010/04/13/How-to-Save-BlackBerry-Application-Settings-in-the-Persistent-Store.aspx . Below is some code from one of my projects. public class PreferencesStore { // Not a real key

I'm not very familiar with the many-to-many insertion process using Entity Framework 4, POCO. I have a blog with 3 tables: Post, Comment, and Tag. A Post can have many Tags and a Tag can be in many Posts . Here are the Post and Tag models: public class Tag { public int Id { get; set; } [Required] [StringLength(25, ErrorMessage = "Tag name can't exceed 25 characters.")] public string Name { get; set; } public virtual ICollection<Post> Posts { get; set; } } public class Post { public int Id { get; set; } [Required] [StringLength(512, ErrorMessage = "Title can't exceed 512 characters")] public

I'm having a problem with injecting EntityManager by using @PersistenceContext. I try to inject EntityManager in EJB class with @PersistenceContext and I always get NullPointerException. Here is EJB class: @Stateless public class BookEJB { public BookEJB(){ } @PersistenceContext(unitName = "BookWebStorePU") private EntityManager em; public Book createBook(Book book) throws Exception { System.out.println("EM: " + em); em.persist(book); return book; } public Book findBookByIsbn10(String isbn10){ Book book = new Book(); em.find(Book.class, isbn10); return book; } //Other methods here } Here's

I have a Book class: public class Book extends SugarRecord { private String mBookName; private String mAuthorName; private List<Page> mPageList; public Book() { } public Book(String bookname, String authorName) { mBookName = bookname; mAuthorName = authorName; mPageList = new ArrayList<>(); } public String getAuthorName() { return mAuthorName; } public void setAuthorName(String authorName) { mAuthorName = authorName; } public String getBookName() { return mBookName; } public void setBookName(String bookName) { mBookName = bookName; } public void addPage(Page page) { mPageList.add(page); } }