Java Web Services in a Nutshell

Name

Handler

Synopsis

public interface Handler {
// Public Instance Methods
    public abstract void destroy(  ); 
    public abstract javax.xml.namespace.QName[ ] getHeaders(  ); 
    public abstract boolean handleFault(MessageContext context); 
    public abstract boolean handleRequest(MessageContext context);
    public abstract boolean handleResponse(MessageContext context);
    public abstract void init( HandlerInfo config); 
}

The Handler interface defines the methods that must be implemented by a message handler. The init( ) and destroy( ) methods mark the beginning and end of the handler’s life cycle. The init( ) method receives a Map containing property values that are typically set from a configuration file such as the jaxrpc-ri.xml file used by wsdeploy, the config.xml used by wscompile, or the webservices.xml file supplied to the J2EE 1.4 j2eec utility. The getHeaders( ) method returns the URIs of all of the headers that the handler can process, in the form of an array of javax.xml.namespace.QName objects. A handler whose processing is not directly related to a header should return an empty array.

The handler processing is carried out by the handleRequest( ), handleResponse( ), and handleFault( ) methods, which are called for an outgoing message, an incoming message that is not a fault, and a fault, respectively. Each of these methods is passed a MessageContext object that handlers can use to store state that can then be read by other handlers in the chain. The MessageContext object can also be used ...