Good evening. I'm new user with hibernate and I need change all my project and put hibernate.

I have next doubts:


1- How could I put the password and user from my java application to hibernate.hbm.xml file.

Right now I have this:
<hibernate-configuration>
<session-factory>
<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/clinica</property>
<property name="hibernate.connection.username">clinica</property>
<property name="hibernate.connection.password">clinica</property>
<property name="hibernate.show_sql">true</property>
<mapping resource="hibernate/Param.hbm.xml"/>
</session-factory>
</hibernate-configuration>

Bu I would like pass user and password data from my java application.

2- The second doubt, how could I declare a compose key for a class definition, in the next text the key is "cod" but if I need declare cod+dni, how could I do it?

<id name="cod" type="string">
<column name="cod" length="3" />
<generator class="assigned" />
</id>

3- ¿What is better to use xml file or anotations?

4- Between criteria, HQL and SQL what do you recomendate me?

5- ¿How could I check if a database exist from hibernate code?

Excuse me for the long text.
Thank you very much