feat(infra): add AbstractSubjectCenter test class #1338

1. add SubjectCenter test class
2. add remove observer method
3. add get size for Observers method

Co-authored-by: rnmb<19276209+rnmb@users.noreply.github.com>

infra/common/src/main/java/cn/hippo4j/common/extension/design/AbstractSubjectCenter.java

@@ -24,6 +24,7 @@ import lombok.extern.slf4j.Slf4j;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.concurrent.ConcurrentHashMap;
 
 /**
@@ -73,12 +74,12 @@ public class AbstractSubjectCenter {
     }
 
     /**
-     * Remove observer.
-     *
-     * @param observer
+     * remove observe
+     * @param subjectType subject type code
+     * @param observer observer listener
      */
-    public static void remove(Observer observer) {
-        remove(SubjectType.SPRING_CONTENT_REFRESHED.name(), observer);
+    public static void remove(SubjectType subjectType, Observer observer) {
+        remove(subjectType.name(), observer);
     }
 
     /**
@@ -127,6 +128,19 @@ public class AbstractSubjectCenter {
         });
     }
 
+    /**
+     * subject observer size
+     * @param subjectType subject type code
+     * @return list observer size
+     */
+    public static int size(SubjectType subjectType) {
+        List<Observer> observers = OBSERVERS_MAP.get(subjectType.name());
+        if (CollectionUtil.isEmpty(observers)) {
+            return 0;
+        }
+        return observers.size();
+    }
+
     /**
      * Subject type.
      */

infra/common/src/test/java/cn/hippo4j/common/extension/design/AbstractSubjectCenterTest.java

@@ -0,0 +1,47 @@
+package cn.hippo4j.common.extension.design;
+
+import lombok.Getter;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.util.concurrent.atomic.AtomicInteger;
+
+public class AbstractSubjectCenterTest {
+
+    /**
+     *  test Subject center
+     */
+    @Test
+    public void testSubjectCenter() {
+        AbstractSubjectCenter.SubjectType subjectType = AbstractSubjectCenter.SubjectType.THREAD_POOL_DYNAMIC_REFRESH;
+        SubjectNotifyListener subjectNotifyListener = new SubjectNotifyListener();
+        NotifyMessage notifyMessage = new NotifyMessage();
+        Assert.assertEquals(0, notifyMessage.getCount().get());
+
+        AbstractSubjectCenter.register(subjectType, subjectNotifyListener);
+        Assert.assertEquals(1, AbstractSubjectCenter.size(subjectType));
+
+        AbstractSubjectCenter.notify(subjectType, () -> notifyMessage);
+        Assert.assertEquals(1, notifyMessage.getCount().get());
+
+        AbstractSubjectCenter.remove(subjectType.name(), subjectNotifyListener);
+        Assert.assertEquals(0, AbstractSubjectCenter.size(subjectType));
+    }
+
+
+    @Getter
+    private static final class NotifyMessage {
+        private final AtomicInteger count = new AtomicInteger(0);
+    }
+
+    /**
+     * Subject Response Listener
+     */
+    private static final class SubjectNotifyListener implements Observer<NotifyMessage>{
+
+        @Override
+        public void accept(ObserverMessage<NotifyMessage> observerMessage) {
+            observerMessage.message().getCount().incrementAndGet();
+        }
+    }
+}