### XFire Home Bug/Issue Reporting Download FAQ Get Involved License News Stack Comparison Support User's Guide XFire Team ### M5 Javadocs Reports ### M6-SNAPSHOT Javadocs Reports ### Developers Developer Space CVS Building Architecture Interesting Projects Release Process | Handlers can be used to do all sorts of things with XFire. They can process the SOAP Body or they can process a particular header and take action based on it. To write a handler just extend the AbstractHandler class:
    import org.codehaus.xfire.MessageContext;
    import org.codehaus.xfire.handler.AbstractHandler;

    public class YourHandler extends AbstractHandler
    {
        public void invoke(MessageContext context)
        {
            // Do some processing...
        }
    }
Handlers can be registered with a Service or a Transport. On both Services and Transports you can stick a handler in a request or response pipeline:
    Servic s = ...;

    // Do this to add a handler to the incoming flow
    s.addInHandler(new YourHandler());

    // Do this to add a handler to the outgoing flow
    s.addOutHandler(new YourHandler());

    // Do this to add a handler to the faultflow
    s.addFaultHandler(new YourHandler());
## Processing SOAP Headers If you are using the "mustUnderstand" feature of SOAP you must tell XFire which QNames you can handle:
    import org.codehaus.xfire.MessageContext;
    import org.codehaus.xfire.handler.AbstractHandler;

    public class YourHandler extends AbstractHandler
    {
        ....
        public QName[] getUnderstoodHeaders()
        {
            return new QName[] { new QName("YourHeader", "urn:your:header:ns") };
        }
    }
## Writing an Authentication Handler Often you will want to authenticate use of your service based on particular Headers in the SOAP Message. Say for example we have a header like the following:
    <AuthenticationToken xmlns="urn:yourapp:authentication">
      <Username>test</Username>
      <Password>123</Password>
    </AuthenticationToken>
We can easily write a Handler to process this information.
    import org.codehaus.xfire.MessageContext;
    import org.codehaus.xfire.handler.AbstractHandler;
    import org.codehaus.yom.Element;

    public class AuthenticationHandler extends AbstractHandler
    {
        private final static String TOKEN_NS = "urn:yourapp:authentication";

        public void invoke(MessageContext context)
            throws XFireFault
        {
            if (context.getRequestHeader() == null)
            {
                throw new XFireFault("Request must include company authentication token.",
                                     XFireFault.SENDER);
            }

            Element token = context.getRequestHeader().getFirstChildElement("AuthenticationToken", TOKEN_NS);
            if (token == null)
            {
                throw new XFireFault("Request must include authentication token.",
                                     XFireFault.SENDER);
            }

            String username = token.getFirstChildElement("Username", TOKEN_NS).getValue();
            String password = token.getFirstChildElement("Password", TOKEN_NS).getValue();

            try
            {
                // Do some authentication....
                ....

                // we've authenticated, now put the Company object in the context
                context.setProperty(COMPANY_KEY, company);
            }
            catch (Exception e)
            {
                throw new XFireFault("Invalid username/password.", XFireFault.SENDER);
            }
        }
    }