How to Create DB Context File in hibernate in java like Entity Framework c#

Question

I have been working in .NET using Entity Framework with fluent API. I created database context with all the relations of entities to map with tables and relations with entities with one to many etc.

I know the annotations way and mapping via XML files.

Following is the code in c#

    public class BloggingContext : DbContext 
{ 
    public DbSet<Blog> Blogs { get; set; } 
    public DbSet<Post> Posts { get; set; } 
    public DbSet<User> Users { get; set; } 

    protected override void OnModelCreating(DbModelBuilder modelBuilder) 
    { 
        modelBuilder.Entity<User>() 
            .Property(u => u.DisplayName) 
            .HasColumnName("display_name"); 
    } 
}

Can any one tell me how to set a file in hibernate in JAVA to create the Blogs table for entity Blog and set properties for any entity with database rather then creating adding annotations.

Answer 1

Just some suggesions: Hibernate does not have the concept of Context but I usually insert a Context class where I set Hibernate Configuration class (one time for the project) and where I retrieve a session (Configuration.BuildSessionFactory() to get a ISessionFactory one time for the project and then ISessionFactory.OpenSession() or other methods similar to it). A session is the class where you start to build queries and insert/update/delete objects (so the usage is similar to the EF Context - you don't implement a Session like a DbContext -).

Usually you build the mapping using xml files like this

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" namespace="FiPlan.Data.Entities" assembly="FiPlan.Engine">
  <class name="Account" table="Accounts" >
    <id name="Id" column="ID" type="String" length="15" >
      <generator class="assigned" />
    </id>
    <property name="Description" column="Description" type="String" not-null="false" length="50" />
  </class>
</hibernate-mapping>

You add this files to the Configuration class (the one where you start to get a session).

Another consideration: there isn't the DbSet concept (every configured class can be accessed via queries).

I know that is not what you are looking for but I hope that this could be an help when you will start to read the Hibernate manual.