/*
 * Copyright 2001-2004 The Apache Software Foundation.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package javax.xml.rpc.handler;

import javax.xml.namespace.QName;

/**
 * The <code>javax.xml.rpc.handler.GenericHandler</code> class
 * implements the <code>Handler</code> interface. SOAP Message
 * Handler developers should typically subclass
 * <code>GenericHandler</code> class unless the Handler class
 * needs another class as a superclass.
 *
 * <p>
 * The <code>GenericHandler</code> class is a convenience abstract
 * class that makes writing Handlers easy. This class provides
 * default implementations of the lifecycle methods <code>init</code>
 * and <code>destroy</code> and also different handle methods.
 * A Handler developer should only override methods that it needs
 * to specialize as part of the derived <code>Handler</code>
 * implementation class.
 *
 * @version 1.0
 */
public abstract class GenericHandler implements Handler {

    /**
     * Default constructor.
     */
    protected GenericHandler() {}

    /**
     * The <code>handleRequest</code> method processes the request
     * SOAP message. The default implementation of this method returns
     * <code>true</code>. This indicates that the handler chain
     * should continue processing of the request SOAP message.
     * This method should be overridden if the derived Handler class
     * needs to specialize implementation of this method.
     *
     * @param context the message context
     * @return true/false
     */
    public boolean handleRequest(MessageContext context) {
        return true;
    }

    /**
     * The <code>handleResponse</code> method processes the response
     * message. The default implementation of this method returns
     * <code>true</code>. This indicates that the handler chain
     * should continue processing of the response SOAP message.
     * This method should be overridden if the derived Handler class
     * needs to specialize implementation of this method.
     *
     * @param context the message context
     * @return true/false
     */
    public boolean handleResponse(MessageContext context) {
        return true;
    }

    /**
     * The <code>handleFault</code> method processes the SOAP faults
     * based on the SOAP message processing model. The default
     * implementation of this method returns <code>true</code>. This
     * indicates that the handler chain should continue processing
     * of the SOAP fault. This method should be overridden if
     * the derived Handler class needs to specialize implementation
     * of this method.
     *
     * @param context the message context
     * @return true/false
     */
    public boolean handleFault(MessageContext context) {
        return true;
    }

    /**
     * The <code>init</code> method to enable the Handler instance to
     * initialize itself. This method should be overridden if
     * the derived Handler class needs to specialize implementation
     * of this method.
     *
     * @param config handler configuration
     */
    public void init(HandlerInfo config) {}

    /**
     * The <code>destroy</code> method indicates the end of lifecycle
     * for a Handler instance. This method should be overridden if
     * the derived Handler class needs to specialize implementation
     * of this method.
     */
    public void destroy() {}

    /**
     * Gets the header blocks processed by this Handler instance.
     *
     * @return Array of QNames of header blocks processed by this handler instance.
     * <code>QName</code> is the qualified name of the outermost element of the Header block.
     */
    public abstract QName[] getHeaders();
}