HOW to generate Hibernate mapping file and annotation code from database automatically

from: http://www.mkyong.com/hibernate/how-to-generate-code-with-hibernate-tools/

In this article, we show you how to use Hibernate / JBoss Tools to generate Hibernate mapping files (hbm) and annotation code from database automatically.
Tools in this article

1. Eclipse v3.6 (Helios)
2. JBoss / Hibernate Tools v3.2
3. Oracle 11g
4. JDK 1.6

Note
Before proceed, please Install Hibernate / JBoss Tools in Eclipse IDE.

1. Hibernate Perspective

Open your “Hibernate Perspective“. In Eclipse IDE, select “Windows” >> “Open Perspective” >> “Others…” , choose “Hibernate“.

2. New Hibernate Configuration

In Hibernate Perspective, right click and select “Add Configuration…”

In “Edit Configuration” dialog box,

1. In “Project” box, click on the “Browse..” button to select your project.
2. In “Database Connection” box, click “New..” button to create your database settings.
3. In “Configuration File” box, click “Setup” button to create a new or use existing “Hibernate configuration file”, hibernate.cfg.xml.

See your list of your tables in “Hibernate Perspective“.

Sample of “hibernate.cfg.xml“, connect to Oracle 11g database.

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
  <property name="hibernate.connection.driver_class">oracle.jdbc.driver.OracleDriver</property>
  <property name="hibernate.connection.url">jdbc:oracle:thin:@127.0.0.1:1521:MKYONG</property>
  <property name="hibernate.connection.username">mkyong</property>
  <property name="hibernate.connection.password">password</property>
  <property name="hibernate.dialect">org.hibernate.dialect.Oracle10gDialect</property>
  <property name="hibernate.default_schema">MKYONG</property>
 </session-factory>
</hibernate-configuration>

3. Hibernate Code Generation

Now, you are ready to generate the Hibernate mapping files and annotation codes.
- In “Hibernate Perspective”, click “Hibernate code generation” icon (see below figure) and select “Hibernate Code Generation Configuration”

- Create a new configuration, select your “console configuration” (configured in step 2), puts your “Output directory” and checked option “Reverse engineer from JDBC Connection“.

- In “Exporter” tab, select what you want to generate, Model , mapping file (hbm) , DAO, annotation code and etc.

See result

Note
The generated Hibernate mapping file and annotations code are very clean, standard and easy to modify. Try explore more features.