After I attempt to load an item( a row ) from mysql database, the string qualities aren't loaded correctly , and consequently after i print them, there is nothing displayed.

here's my hibernate config file :

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-configuration SYSTEM 
          "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
  <session-factory>    
    <property name="connection.driver_class">
       com.mysql.jdbc.Driver
    </property>
    <property name="connection.url">
      jdbc:mysql://localhost:3306/demo_hib_1
    </property>
    <property name="connection.username">root</property>
    <property name="connection.password"> </property>
    <property name="pool_size">5</property>
    <property name="show_sql">true</property>
    <property name="dialect">
      org.hibernate.dialect.MySQLDialect
    </property>
    <!-- Mapping files -->

     <mapping resource="com/navid/Person.hbm.xml"/>

  </session-factory>
</hibernate-configuration>

I tryed adding encoding to connection url :

jdbc:mysql://localhost:3306/demo_hib_1&characterEncoding=UTF-8

and also got hibernate exception :

Exception in thread "main" org.hibernate.HibernateException: Could not parse configuration: /hibernate.cfg.xml
    at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:2246)
    at org.hibernate.cfg.Configuration.configure(Configuration.java:2158)
    at org.hibernate.cfg.Configuration.configure(Configuration.java:2137)
    at com.navid.Main.main(Main.java:31)
Caused by: org.dom4j.DocumentException: Error on line 10 of document  : The reference to entity "characterEncoding" must end with the ';' delimiter. Nested exception: The reference to entity "characterEncoding" must end with the ';' delimiter.
    at org.dom4j.io.SAXReader.read(SAXReader.java:482)
    at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:2238)
    ... 3 more

The hibernate config file is definitely an XML file, so raw &lifier symbols aren't permitted

Two options that come to mind (but untested!), the very first is always to make use of the XML &amp; escape sequence:

<property name="connection.url">
  jdbc:mysql://localhost:3306/demo_hib_1?useUnicode=true&amp;characterEncoding=UTF-8
</property>

Or using title+value syntax, which wouldn't require the &lifier getting away:

<property name="connection.url" value="jdbc:mysql://localhost:3306/demo_hib_1?useUnicode=true&characterEncoding=UTF-8" />

Observe that I have added a second option too, I want both

Have you try adding

<property name="connection.characterEncoding">UTF-8</property>

to session factory configuration.

From Hibernate documentation:

Arbitrary connection qualities could be distributed by prepending "hibernate.connection" towards the connection property title. For instance, you are able to specify a charSet connection property using hibernate.connection.charSet.