feat: 状态管理器新增是否可切换的检查.

src/main/java/com/serliunx/statemanagement/manager/AbstractStateManager.java

@@ -100,6 +100,11 @@ public abstract class AbstractStateManager<S> implements StateManager<S> {
 		}
 	}
 
+	@Override
+	public boolean isSwitchable() {
+		return stateList.size() > 1;
+	}
+
 	/**
 	 * 将序号移动至下一个
 	 * <li> 自动归零

src/main/java/com/serliunx/statemanagement/manager/BreakageUnidirectionalStateManager.java

@@ -87,4 +87,9 @@ public final class BreakageUnidirectionalStateManager<S> extends DefaultUnidirec
     public void reset() {
         throw new UnsupportedOperationException("Cannot reset state for BreakageUnidirectionalStateManager!");
     }
+
+    @Override
+    public boolean isSwitchable() {
+        return !isLast();
+    }
 }

src/main/java/com/serliunx/statemanagement/manager/StateManager.java

@@ -30,4 +30,13 @@ public interface StateManager<S> {
 	 * 重置回默认状态, 一般为状态集合中的第一个
 	 */
 	void reset();
+
+	/**
+	 * 是否可切换
+	 *
+	 * @return 可切换返回真, 否则返回假
+	 */
+	default boolean isSwitchable() {
+		return true;
+	}
 }

src/test/java/com/serliunx/statemanagement/ManagerTest.java

@@ -29,7 +29,10 @@ public class ManagerTest {
 	@Test
 	public void testBreakageUnidirectionalStateManager() {
 		UnidirectionalStateManager<PrinterState> bum = new BreakageUnidirectionalStateManager<>(PrinterState.values());
-		System.out.println(bum.isCircle());
+
-		bum.switchNext();
+		while (bum.isSwitchable()) {
+			System.out.println(bum.getAndSwitchNext());
+		}
+		System.out.println(bum.current());
 	}
 }