I am getting error while creating simple hibernate application using oracle 10g
ERROR:- 
log4j:WARN No appenders could be found for logger (org.hibernate.cfg.Environment).
log4j:WARN Please initialize the log4j system properly.
Exception in thread "main" org.hibernate.HibernateException: Could not parse configuration: hibernate.cfg.xml
    at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:1491)
    at org.hibernate.cfg.Configuration.configure(Configuration.java:1425)
    at hibernate.StoreData.main(StoreData.java:13)
Caused by: org.dom4j.DocumentException: Error on line 1 of document  : The processing instruction target matching "[xX][mM][lL]" is not allowed. Nested exception: The processing instruction target matching "[xX][mM][lL]" is not allowed.
    at org.dom4j.io.SAXReader.read(SAXReader.java:482)
    at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:1481)
    ... 2 more
Mapping File:-
<?xml version='1.0' encoding='UTF-8'?>  
<!DOCTYPE hibernate-mapping PUBLIC  
 "-//Hibernate/Hibernate Mapping DTD 3.0//EN"  
 "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">  
 <hibernate-mapping>  
  <class name="hibernate.Employee" table="emp1000">  
    <id name="id">  
     <generator class="assigned"></generator>  
    </id>  
    <property name="firstName"></property>  
    <property name="lastName"></property>  
  </class>  
 </hibernate-mapping>  
Configuration file:-
<?xml version='1.0' encoding='UTF-8'?>  
<hibernate-configuration>  
    <session-factory>  
        <property name="hbm2ddl.auto">update</property>  
        <property name="dialect">org.hibernate.dialect.Oracle10gDialect</property>  
        <property name="connection.url">jdbc:oracle:thin:@localhost:1521:xe</property>  
        <property name="connection.username">hr</property>  
        <property name="connection.password">hr</property>  
        <property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property>  
    <mapping resource="employee.hbm.xml"/>  
    </session-factory>  
</hibernate-configuration>