UsernameToken in cxf

[siraj baig]

Hi,
I am using apachi cxf to implement web services.
I would like to know how the userid and password values enter by user
will set to " UsernameToken "
Please let me know the flow or please provide me a brief documentation

[ code ]

<bean id="saajInInterceptor" class="org.apache.cxf.binding.soap.saaj.SAAJInInterceptor" abstract="true"/>
<bean id="wss4jInInterceptor" class="org.apache.cxf.ws.security.wss4j.WSS4JInInterceptor" abstract="true">
<constructor-arg>
<map>
<entry key="action" value="UsernameToken"/>
<entry key="passwordType" value="PasswordText"/>
<entry key="passwordCallbackClass" value="com.bipt.tiva.ws.ServerPasswordCallback"/>
</map>
</constructor-arg>
</bean>

[/ code ]

Thanks
siraj.