开源工作流Fireflow源码分析之ActivityInstance fired-优快云博客

本文深入解析了开源工作流引擎Fireflow中ActivityInstance类的事件处理机制，包括Activity触发事件的响应、ActivityFired事件的触发过程以及ActivityCompleted事件的处理逻辑。重点介绍了如何通过事件监听器实现自定义事件处理逻辑。

ActivityInstance.java

 /* Activity触发事件
     * @see org.fireflow.kernel.INodeInstance#fire(org.fireflow.kernel.IToken)
     */
    public void fire(IToken tk) throws KernelException {
    	//打印权重.
        log.debug("The weight of the Entering TransitionInstance is " + tk.getValue());
        IToken token = tk;
        //设置当前的节点实例ID
        token.setNodeId(this.getActivity().getId());
        //触发Activity Entered事件
        NodeInstanceEvent event1 = new NodeInstanceEvent(this);
        event1.setToken(tk);
        event1.setEventType(NodeInstanceEvent.NODEINSTANCE_TOKEN_ENTERED);
        fireNodeEvent(event1);
        //如果token是活动的
        //注:关于token的状态(alive or dead),是由TranstionInstance决定的,详见<<开源工作流Fireflow源码分析之运行流程二>>
        if (token.isAlive()) {
        	//触发Activity Fired事件
            NodeInstanceEvent event = new NodeInstanceEvent(this);
            event.setToken(token);
            event.setEventType(NodeInstanceEvent.NODEINSTANCE_FIRED);
            //详见下面介绍
            fireNodeEvent(event);
        } else {
        	//如果token是dead状态，那么就直接结束当前节点。
        	//详见<<开源工作流Fireflow源码分析之ActivityInstance completed一.doc>>
            this.complete(token, null);
        }
}

AbstractNodeInstance.java

/**
	 * 触发ActivityInstance各种事件，实现类中根据事件的不同而进行触发
	 * @param event
	 * @throws KernelException
	 */
	public void fireNodeEvent(NodeInstanceEvent event) throws KernelException{
		//遍历当前节点的事件监听器，依次进行触发
		for (int i=0;i<this.eventListeners.size();i++){
			INodeInstanceEventListener listener = this.eventListeners.get(i);
			listener.onNodeInstanceEventFired(event);
		}
	}

ActivityInstance默认的事件监听器为ActivityInstanceExtension

 /* ActivityInstance事件触发
     * @see org.fireflow.kernel.event.INodeInstanceEventListener#onNodeInstanceEventFired(org.fireflow.kernel.event.NodeInstanceEvent)
     */
    public void onNodeInstanceEventFired(NodeInstanceEvent e)
            throws KernelException {
    	//如果事件为fired 
        if (e.getEventType() == NodeInstanceEvent.NODEINSTANCE_FIRED) {
            //取到spring中定义的持久化类
            IPersistenceService persistenceService = rtCtx.getPersistenceService();
            //保存token，并创建taskinstance
            persistenceService.saveOrUpdateToken(e.getToken());
            //取到task管理器，创建activity Task.
          //详见<<开源工作流Fireflow源码分析之ActivityInstance Created Task>>

   rtCtx.getTaskInstanceManager().createTaskInstances(e.getToken(), (IActivityInstance) e.getSource());
        } else if (e.getEventType() == NodeInstanceEvent.NODEINSTANCE_COMPLETED) {
          	//如果事件为completed,作者未处理
        }
    }

转载于:https://www.cnblogs.com/mzhanker/archive/2011/06/06/2073812.html