Activiti源码学习：ExecutionListener与TaskListener的区别-优快云博客

本文介绍了流程引擎中两种主要的监听器：ExecutionListener与TaskListener。前者负责在流程实例启动、结束及过渡时触发，后者则关注任务创建、分配、完成及删除等事件。两种监听器通过不同的代理对象DelegateExecution和DelegateTask实现对流程状态变化的通知。

/** Callback interface to be notified of execution events like starting a process instance,
 * ending an activity instance or taking a transition.
 *  
 * @author Tom Baeyens
 * @author Joram Barrez
 */
public interface ExecutionListener extends Serializable {

  String EVENTNAME_START = "start";
  String EVENTNAME_END = "end";
  String EVENTNAME_TAKE = "take";

  void notify(DelegateExecution execution) throws Exception;
}

/**
 * @author Tom Baeyens
 */
public interface TaskListener extends Serializable {

  String EVENTNAME_CREATE = "create";
  String EVENTNAME_ASSIGNMENT = "assignment";
  String EVENTNAME_COMPLETE = "complete";
  String EVENTNAME_DELETE = "delete";
  
  
  /**
   * Not an actual event, used as a marker-value for {@link TaskListener}s that should be called for all events,
   * including {@link #EVENTNAME_CREATE}, {@link #EVENTNAME_ASSIGNMENT} and {@link #EVENTNAME_COMPLETE} and {@link #EVENTNAME_DELETE}.
   */
  String EVENTNAME_ALL_EVENTS = "all";
  
  void notify(DelegateTask delegateTask);
}