/*
* 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.jaxws.client.async;
import org.apache.axis2.AxisFault;
import org.apache.axis2.client.async.AsyncResult;
import org.apache.axis2.client.async.Callback;
import org.apache.axis2.jaxws.core.InvocationContext;
import org.apache.axis2.jaxws.core.MessageContext;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import javax.xml.ws.AsyncHandler;
import javax.xml.ws.WebServiceException;
import java.util.concurrent.Callable;
import java.util.concurrent.Executor;
import java.util.concurrent.Future;
import java.util.concurrent.FutureTask;
/**
* The CallbackFuture implements the Axis2 <link>org.apache.axis2.client.async.Callback</link> API
* and will get registered with the Axis2 engine to receive the asynchronous callback responses.
* This object is also responsible for taking the <link>java.util.concurrent.Executor</link> given
* to it by the JAX-WS client and using that as the thread on which to deliver the async response
* the JAX-WS <link>javax.xml.ws.AsynchHandler</link>.
*/
public class CallbackFuture extends Callback {
private static final Log log = LogFactory.getLog(CallbackFuture.class);
private static final boolean debug = log.isDebugEnabled();
private CallbackFutureTask cft;
private Executor executor;
private FutureTask task;
private InvocationContext invocationCtx;
/*
* There are two Async Callback Future.cancel scenario that we address
* 1) Client app creates request and call Async Operation. Now before the request is submitted
* by JAXWS to Executor for processing and any response is received client decides to cancel
* the future task.
* 2) Client app creates request and call Async Operation. Request is submitted by JAXWS
* to Executor for processing and a response is received and client decides to cancel the future
* task.
*
* We will address both these scenarios in the code. In scenario 1 we will do the following:
* 1) Check the for the future.isCancelled before submitting the task to Executor
* 2) If cancelled then do not submit the task and do not call the Async Handler of client.
* 3)The client program in this case (Since it cancelled the future) will be responsible for cleaning any resources that it engages.
*
* In Second Scenario we will call the AsyncHandler as Future.isCancelled will be false. As per java doc
* the Future cannot be cancelled once the task has been submitted. Also the response has already arrived so
* we will make the AsyncHandler and let the client code decided how it wants to treat the response.
*/
@SuppressWarnings("unchecked")
public CallbackFuture(InvocationContext ic, AsyncHandler handler) {
cft = new CallbackFutureTask(ic.getAsyncResponseListener(), handler);
task = new FutureTask(cft);
executor = ic.getExecutor();
/*
* TODO review. We need to save the invocation context so we can set it on the
* response (or fault) context so the FutureCallback has access to the handler list.
*/
invocationCtx = ic;
}
public Future<?> getFutureTask() {
return (Future<?>)task;
}
@Override
public void onComplete(AsyncResult result) {
if (debug) {
log.debug("JAX-WS received the async response");
}
MessageContext response = null;
try {
response = AsyncUtils.createJAXWSMessageContext(result);
response.setInvocationContext(invocationCtx);
// make sure request and response contexts share a single parent
response.setMEPContext(invocationCtx.getRequestMessageContext().getMEPContext());
} catch (WebServiceException e) {
cft.setError(e);
if (debug) {
log.debug(
"An error occured while processing the async response. " + e.getMessage());
}
}
if (response == null) {
// TODO: throw an exception
}
cft.setMessageContext(response);
execute();
}
@Override
public void onError(Exception e) {
// If a SOAPFault was returned by the AxisEngine, the AxisFault
// that is returned should have a MessageContext with it. Use
// this to unmarshall the fault included there.
if (e.getClass().isAssignableFrom(AxisFault.class)) {
AxisFault fault = (AxisFault)e;
MessageContext faultMessageContext = null;
try {
faultMessageContext = AsyncUtils.createJAXWSMessageContext(fault.getFaultMessageContext());
faultMessageContext.setInvocationContext(invocationCtx);
// make sure request and response contexts share a single parent
faultMessageContext.setMEPContext(invocationCtx.getRequestMessageContext().getMEPContext());
} catch (WebServiceException wse) {
cft.setError(wse);
}
cft.setError(e);
cft.setMessageContext(faultMessageContext);
} else {
cft.setError(e);
}
execute();
}
private void execute() {
if (log.isDebugEnabled()) {
log.debug("Executor task starting to process async response");
}
if (executor != null) {
if (task != null && !task.isCancelled()) {
try {
executor.execute(task);
}
catch (Exception executorExc) {
if (log.isDebugEnabled()) {
log.debug("CallbackFuture.execute(): executor exception [" +
executorExc.getClass().getName() + "]");
}
// attempt to cancel the FutureTask
task.cancel(true);
// note: if it is becomes required to return the actual exception
// to the client, then we would need to doing something
// similar to setting the CallbackFutureTask with the error
// and invoking the CallbackFutureTask.call() interface
// to process the information
//
}
if (log.isDebugEnabled()) {
log.debug("Task submitted to Executor");
}
} else {
if (log.isDebugEnabled()) {
log.info(
"Executor task was not sumbitted as Async Future task was cancelled by clients");
}
}
}
if (log.isDebugEnabled()) {
log.debug("Executor task completed");
}
}
}
class CallbackFutureTask implements Callable {
private static final Log log = LogFactory.getLog(CallbackFutureTask.class);
private static final boolean debug = log.isDebugEnabled();
AsyncResponse response;
MessageContext msgCtx;
AsyncHandler handler;
Exception error;
CallbackFutureTask(AsyncResponse r, AsyncHandler h) {
response = r;
handler = h;
}
void setMessageContext(MessageContext mc) {
msgCtx = mc;
}
void setError(Exception e) {
error = e;
}
@SuppressWarnings("unchecked")
public Object call() throws Exception {
// Set the response or fault content on the AsyncResponse object
// so that it can be collected inside the Executor thread and processed.
if (error != null) {
response.onError(error, msgCtx);
} else {
response.onComplete(msgCtx);
}
// Now that the content is available, call the JAX-WS AsyncHandler class
// to deliver the response to the user.
try {
ClassLoader cl = handler.getClass().getClassLoader();
if (log.isDebugEnabled()) {
log.debug("Setting up the thread's ClassLoader");
log.debug(cl.toString());
}
Thread.currentThread().setContextClassLoader(cl);
if (debug) {
log.debug("Calling JAX-WS AsyncHandler with the Response object");
log.debug("AyncHandler class: " + handler.getClass());
}
handler.handleResponse(response);
}
catch (Throwable t) {
if (debug) {
log.debug("An error occured while invoking the callback object.");
log.debug("Error: " + t.getMessage());
}
}
return null;
}
}