/*
* 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.tuscany.sca.core.invocation;
import java.util.UUID;
import org.apache.tuscany.sca.interfacedef.ConversationSequence;
import org.apache.tuscany.sca.interfacedef.Interface;
import org.apache.tuscany.sca.interfacedef.Operation;
import org.apache.tuscany.sca.invocation.InvocationChain;
import org.apache.tuscany.sca.invocation.Invoker;
import org.apache.tuscany.sca.invocation.Message;
import org.apache.tuscany.sca.invocation.MessageFactory;
import org.apache.tuscany.sca.runtime.RuntimeWire;
/**
* Base class for performing invocations on a wire. Subclasses are responsible for retrieving and supplying the
* appropriate chain, target invoker, and invocation arguments.
*
* @version $Rev: 538423 $ $Date: 2007-05-16 05:11:06 +0100 (Wed, 16 May 2007) $
*/
public abstract class AbstractInvocationHandler {
protected boolean conversational;
private boolean conversationStarted;
private MessageFactory messageFactory;
protected AbstractInvocationHandler(MessageFactory messageFactory, boolean conversational) {
this.conversational = conversational;
this.messageFactory = messageFactory;
}
protected Object invoke(InvocationChain chain, Object[] args, RuntimeWire wire) throws Throwable {
Message msgContext = ThreadMessageContext.getMessageContext();
Message msg = messageFactory.createMessage();
if (conversational) {
Object id = msgContext.getConversationID();
if (id == null) {
String convIdFromThread = createConversationID();
msg.setConversationID(convIdFromThread);
}
}
Invoker headInvoker = chain.getHeadInvoker();
msg.setCorrelationID(msgContext.getCorrelationID());
Operation operation = chain.getTargetOperation();
Interface contract = operation.getInterface();
if (contract != null && contract.isConversational()) {
ConversationSequence sequence = chain.getTargetOperation().getConversationSequence();
if (sequence == ConversationSequence.CONVERSATION_END) {
msg.setConversationSequence(ConversationSequence.CONVERSATION_END);
conversationStarted = false;
} else if (sequence == ConversationSequence.CONVERSATION_CONTINUE) {
if (conversationStarted) {
msg.setConversationSequence(ConversationSequence.CONVERSATION_CONTINUE);
} else {
conversationStarted = true;
msg.setConversationSequence(ConversationSequence.CONVERSATION_START);
}
}
}
msg.setBody(args);
msg.setFrom(wire.getSource());
msg.setTo(wire.getTarget());
ThreadMessageContext.setMessageContext(msg);
try {
// dispatch the wire down the chain and get the response
Message resp = headInvoker.invoke(msg);
Object body = resp.getBody();
if (resp.isFault()) {
throw (Throwable)body;
}
return body;
} finally {
ThreadMessageContext.setMessageContext(msgContext);
}
}
/**
* Creates a new conversational id
*
* @return the conversational id
*/
private String createConversationID() {
return UUID.randomUUID().toString();
}
}