change: 代码整理、定向切换时校验当前状态.

src/main/java/com/serliunx/statemanagement/machine/StandardStateMachine.java

@@ -149,8 +149,16 @@ public class StandardStateMachine<S> extends AbstractStateManager<S> implements
 
 	@Override
 	public boolean switchTo(S state) {
+		int i = indexOf(state);
+		if (i == -1 || i == currentIndex()) {
+			return false;
+		}
 		try {
 			writeLock.lock();
+			// 重新检查
+			if (i == currentIndex()) {
+				return false;
+			}
 			S oldState = get();
 			boolean result = super.switchTo(state);
 			if (result) {

src/main/java/com/serliunx/statemanagement/machine/StateMachine.java

@@ -11,7 +11,7 @@ import com.serliunx.statemanagement.manager.BidirectionalStateManager;
  * <li> 切出指定状态时触发	(离开事件)
  * <li> 从A切换到B状态时触发	(交换事件)
  * <p>
- * 推荐使用{@link StateMachineBuilder} 来构建状态机.
+ * 请使用{@link StateMachineBuilder} 来构建状态机.
  *
  * @author <a href="mailto:serliunx@yeah.net">SerLiunx</a>
  * @version 1.0.0
@@ -22,5 +22,12 @@ import com.serliunx.statemanagement.manager.BidirectionalStateManager;
  */
 public interface StateMachine<S> extends BidirectionalStateManager<S> {
 
-
+    /**
+     * 切换到指定状态
+     * <li> 在使用状态机的情况, 仅切换成功才会触发注册的各种事件.
+     *
+     * @param state 新的状态
+     * @return 切换成功返回真, 否则返回假
+     */
+    boolean switchTo(S state);
 }

src/main/java/com/serliunx/statemanagement/machine/StateMachineBuilder.java

@@ -2,7 +2,6 @@ package com.serliunx.statemanagement.machine;
 
 import com.serliunx.statemanagement.machine.handler.StateHandler;
 import com.serliunx.statemanagement.machine.handler.StateHandlerWrapper;
-import com.serliunx.statemanagement.manager.BidirectionalStateManager;
 
 import java.util.*;
 import java.util.concurrent.Executor;

src/main/java/com/serliunx/statemanagement/machine/handler/StateHandlerProcessParams.java

@@ -1,7 +1,5 @@
 package com.serliunx.statemanagement.machine.handler;
 
-import com.serliunx.statemanagement.manager.BidirectionalStateManager;
-
 /**
  * 状态处理器入参
  * <p>