axisengine.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you 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 org.apache.axis2.engine;

import org.apache.axiom.soap.SOAPEnvelope;
import org.apache.axiom.soap.SOAPHeaderBlock;
import org.apache.axis2.AxisFault;
import org.apache.axis2.client.async.Callback;
import org.apache.axis2.client.async.AxisCallback;
import org.apache.axis2.context.ConfigurationContext;
import org.apache.axis2.context.MessageContext;
import org.apache.axis2.context.OperationContext;
import org.apache.axis2.description.AxisOperation;
import org.apache.axis2.description.TransportOutDescription;
import org.apache.axis2.engine.Handler.InvocationResponse;
import org.apache.axis2.i18n.Messages;
import org.apache.axis2.transport.TransportSender;
import org.apache.axis2.util.CallbackReceiver;
import org.apache.axis2.util.LoggingControl;
import org.apache.axis2.util.MessageContextBuilder;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import javax.xml.namespace.QName;
import java.util.ArrayList;
import java.util.Iterator;

/**
 * There is one engine for the Server and the Client. the send() and receive()
 * Methods are the basic operations the Sync, Async messageing are build on top.
 */
public class AxisEngine {

    /**
     * Field log
     */
    private static final Log log = LogFactory.getLog(AxisEngine.class);

    private static boolean RESUMING_EXECUTION = true;
    private static boolean NOT_RESUMING_EXECUTION = false;

    /**
     * Constructor AxisEngine
     */
    public AxisEngine(ConfigurationContext engineContext) {
    }

    private static void checkMustUnderstand(MessageContext msgContext) throws AxisFault {
        SOAPEnvelope envelope = msgContext.getEnvelope();
        if (envelope.getHeader() == null) {
            return;
        }

        // Get all the headers targeted to us
        Iterator headerBlocks = envelope.getHeader().getHeadersToProcess(null);

        while (headerBlocks.hasNext()) {
            SOAPHeaderBlock headerBlock = (SOAPHeaderBlock) headerBlocks.next();

            // if this header block has been processed or mustUnderstand isn't
            // turned on then its cool
            if (headerBlock.isProcessed() || !headerBlock.getMustUnderstand()) {
                continue;
            }

            // Oops, throw an appropriate MustUnderstand fault!!
            QName faultQName = headerBlock.getVersion().getMustUnderstandFaultCode();
            throw new AxisFault(Messages.getMessage("mustunderstandfailed",
                                                    headerBlock.getNamespace().getNamespaceURI(),
                                                    headerBlock.getLocalName()), faultQName);
        }
    }

    /**
     * This method is called to handle any error that occurs at inflow or outflow. But if the
     * method is called twice, it implies that sending the error handling has failed, in which case
     * the method logs the error and exists.
     *
     * @deprecated (post 1.1 branch)
     */
    public static MessageContext createFaultMessageContext(MessageContext processingContext, Throwable e)
            throws AxisFault {
        return MessageContextBuilder.createFaultMessageContext(processingContext, e);
    }

    /**
     * This methods represents the inflow of the Axis, this could be either at the server side or the client side.
     * Here the <code>ExecutionChain</code> is created using the Phases. The Handlers at the each Phases is ordered in
     * deployment time by the deployment module
     *
     * @throws AxisFault
     * @see MessageContext
     * @see Phase
     * @see Handler
     */
    public static InvocationResponse receive(MessageContext msgContext) throws AxisFault {
        if (LoggingControl.debugLoggingAllowed && log.isTraceEnabled()) {
            log.trace(msgContext.getLogIDString() + " receive:" + msgContext.getMessageID());
        }
        ConfigurationContext confContext = msgContext.getConfigurationContext();
        ArrayList preCalculatedPhases;
        if (msgContext.isFault() || msgContext.isProcessingFault()) {
            preCalculatedPhases = confContext.getAxisConfiguration().getInFaultFlowPhases();
            msgContext.setFLOW(MessageContext.IN_FAULT_FLOW);
        } else {
            preCalculatedPhases = confContext.getAxisConfiguration().getInFlowPhases();
            msgContext.setFLOW(MessageContext.IN_FLOW);
        }
        // Set the initial execution chain in the MessageContext to a *copy* of what
        // we got above.  This allows individual message processing to change the chain without
        // affecting later messages.
        msgContext.setExecutionChain((ArrayList) preCalculatedPhases.clone());
        try {
            InvocationResponse pi = invoke(msgContext, NOT_RESUMING_EXECUTION);

            if (pi.equals(InvocationResponse.CONTINUE)) {
                checkMustUnderstand(msgContext);
                if (msgContext.isServerSide()) {
                    // invoke the Message Receivers

                    MessageReceiver receiver = msgContext.getAxisOperation().getMessageReceiver();
                    if (receiver == null) {
                        throw new AxisFault(Messages.getMessage(
                                "nomessagereciever",
                                msgContext.getAxisOperation().getName().toString()));
                    }
                    receiver.receive(msgContext);
                }
                flowComplete(msgContext);
            } else if (pi.equals(InvocationResponse.SUSPEND)) {
                return pi;
            } else if (pi.equals(InvocationResponse.ABORT)) {
                flowComplete(msgContext);
                return pi;
            } else {
                String errorMsg =
                        "Unrecognized InvocationResponse encountered in AxisEngine.receive()";
                log.error(msgContext.getLogIDString() + " " + errorMsg);
                throw new AxisFault(errorMsg);
            }
        }
        catch (AxisFault e) {
            msgContext.setFailureReason(e);
            flowComplete(msgContext);
            throw e;
        }

        return InvocationResponse.CONTINUE;
    }

    private static void processFault(MessageContext msgContext, AxisFault e) {
        try {
            MessageContext faultMC = MessageContextBuilder.createFaultMessageContext(msgContext, e);

            // Figure out where this goes
            sendFault(faultMC);
        } catch (AxisFault axisFault) {
            log.error(axisFault.getMessage(), axisFault);
        }
    }

    /**
     * Take the execution chain from the msgContext , and then take the current Index
     * and invoke all the phases in the arraylist
     * if the msgContext is pauesd then the execution will be breaked
     *
     * @param msgContext
     * @return An InvocationResponse that indicates what
     *         the next step in the message processing should be.
     * @throws AxisFault
     */
    private static InvocationResponse invoke(MessageContext msgContext, boolean resuming)
            throws AxisFault {

        if (msgContext.getCurrentHandlerIndex() == -1) {
            msgContext.setCurrentHandlerIndex(0);
        }

        InvocationResponse pi = InvocationResponse.CONTINUE;

        while (msgContext.getCurrentHandlerIndex() < msgContext.getExecutionChain().size()) {
            Handler currentHandler = (Handler) msgContext.getExecutionChain().
                    get(msgContext.getCurrentHandlerIndex());

            try {
                if (!resuming) {
                    msgContext.addExecutedPhase(currentHandler);
                } else {
                    /* If we are resuming the flow, we don't want to add the phase
                    * again, as it has already been added.
                    */
                    resuming = false;
                }
                pi = currentHandler.invoke(msgContext);
            }
            catch (AxisFault e) {
                if (msgContext.getCurrentPhaseIndex() == 0) {
                    /* If we got a fault, we still want to add the phase to the
                    list to be executed for flowComplete(...) unless this was
                    the first handler, as then the currentPhaseIndex will be
                    set to 0 and this will look like we've executed all of the
                    handlers.  If, at some point, a phase really needs to get
                    notification of flowComplete, then we'll need to introduce
                    some more complex logic to keep track of what has been
                    executed.*/
                    msgContext.removeFirstExecutedPhase();
                }
                throw e;
            }

            if (pi.equals(InvocationResponse.SUSPEND) ||
                    pi.equals(InvocationResponse.ABORT)) {
                break;
            }

            msgContext.setCurrentHandlerIndex(msgContext.getCurrentHandlerIndex() + 1);
        }

        return pi;
    }

    private static void flowComplete(MessageContext msgContext) {
        Iterator invokedPhaseIterator = msgContext.getExecutedPhases();

        while (invokedPhaseIterator.hasNext()) {
            Handler currentHandler = ((Handler) invokedPhaseIterator.next());
            currentHandler.flowComplete(msgContext);
        }

        /*This is needed because the OutInAxisOperation currently invokes
        * receive() even when a fault occurs, and we will have already executed
        * the flowComplete on those before receiveFault() is called.
        */
        msgContext.resetExecutedPhases();
    }

    /**
     * If the msgConetext is puased and try to invoke then
     * first invoke the phase list and after the message receiver
     *
     * @param msgContext
     * @return An InvocationResponse allowing the invoker to perhaps determine
     *         whether or not the message processing will ever succeed.
     * @throws AxisFault
     */
    public static InvocationResponse resumeReceive(MessageContext msgContext) throws AxisFault {
        if (LoggingControl.debugLoggingAllowed && log.isTraceEnabled()) {
            log.trace(msgContext.getLogIDString() + " resumeReceive:" + msgContext.getMessageID());
        }

        //REVIEW: This name is a little misleading, as it seems to indicate that there should be a resumeReceiveFault as well, when, in fact, this does both
        //REVIEW: Unlike with receive, there is no wrapping try/catch clause which would
        //fire off the flowComplete on an error, as we have to assume that the