[Change][Document] Core 修正 ThreadPoolEventExecutor 文档错误, 添加对 Cancelable 事件的操作细节;

[Change] ThreadPoolEventExecutor 适配 HandlerRegistry 更改;
[Change] ThreadPoolEventExecutor 对内部类 'ExecuteRunnable' 添加对 Cancelable 事件的更多处理;
[Document] ThreadPoolEventExecutor 修正文档错误;

ContentGrabbingJi-core/src/main/java/net/lamgc/cgj/bot/event/ThreadPoolEventExecutor.java

@@ -24,25 +24,27 @@ import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.util.Map;
 import java.util.Objects;
+import java.util.Observable;
+import java.util.Observer;
 import java.util.concurrent.ThreadPoolExecutor;
 
 /**
  * 基于线程池, 以事件为单位的异步事件执行器.
- * <p> 以事件为单位对于 ContentGrabbingJi 来说是实现难度低, 还很合适的,
+ * <p> 以事件为单位对于 ContentGrabbingJi 来说不仅合适，而且实现难度低,
  * ContentGrabbingJi 只会注册一个 Handler, 所以依然类似于一个 Handler 一个线程.
  * @author LamGC
  */
 public class ThreadPoolEventExecutor implements EventExecutor {
 
     private final ThreadPoolExecutor threadExecutor;
-    private final EventHandlerRegistry registry;
+    private final HandlerRegistry registry;
 
     /**
      * 构造线程池事件执行器.
      * @param threadExecutor 执行器所使用的线程池.
      * @param registry 事件处理注册器.
      */
-    public ThreadPoolEventExecutor(ThreadPoolExecutor threadExecutor, EventHandlerRegistry registry) {
+    public ThreadPoolEventExecutor(ThreadPoolExecutor threadExecutor, HandlerRegistry registry) {
         this.threadExecutor = threadExecutor;
         this.registry = registry;
     }
@@ -60,12 +62,13 @@ public class ThreadPoolEventExecutor implements EventExecutor {
     /**
      * 按事件为单位的事件处理执行类.
      */
-    private final static class ExecuteRunnable implements Runnable {
+    private final static class ExecuteRunnable implements Runnable, Observer {
 
         private final static Logger log = LoggerFactory.getLogger(ExecuteRunnable.class);
 
         private final EventObject event;
         private final Map<Method, Object> handlerMethods;
+        private Thread currentExecuteThread;
 
         private ExecuteRunnable(EventObject event, Map<Method, Object> handlerMethods) {
             this.event = Objects.requireNonNull(event);
@@ -75,6 +78,11 @@ public class ThreadPoolEventExecutor implements EventExecutor {
         @Override
         public void run() {
             if (event instanceof Cancelable) {
+                if (((Cancelable) event).canceled()) {
+                    log.trace("事件 {} 在处理前被取消.", event);
+                    return;
+                }
+                registerCancelHook((Cancelable) event);
                 runCancelableEvent();
             } else {
                 runOrdinaryEvent();
@@ -132,6 +140,22 @@ public class ThreadPoolEventExecutor implements EventExecutor {
             }
         }
 
+        private void registerCancelHook(Cancelable cancelableEvent) {
+            if (!cancelableEvent.observableCancel()) {
+                log.trace("事件 {} 不支持注册取消状态观察者.", cancelableEvent);
+                return;
+            }
+            this.currentExecuteThread = Thread.currentThread();
+            cancelableEvent.registerCancelObserver(this);
+        }
+
+        @Override
+        public void update(Observable o, Object arg) {
+            if (arg == event && this.currentExecuteThread != null) {
+                log.debug("事件 {} 取消状态确认, 已对线程 {} 发起中断.", event, currentExecuteThread);
+                this.currentExecuteThread.interrupt();
+            }
+        }
     }
 
 }