feat(infra): add AbstractSubjectCenter test class #1338 (#1340)

* 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>

* feat(infra): add AbstractSubjectCenter test class
1. add SubjectCenter test class
2. rollback SubjectCenter method

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

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

@@ -0,0 +1,146 @@
+package cn.hippo4j.common.extension.design;
+
+import lombok.Getter;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.lang.reflect.Field;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.atomic.AtomicInteger;
+
+public class AbstractSubjectCenterTest {
+
+
+    private Map<String, List<Observer>> OBSERVERS_MAP ;
+
+    private SubjectNotifyListener subjectNotifyListener;
+
+    @Before
+    public void setUp() throws NoSuchFieldException, IllegalAccessException {
+        subjectNotifyListener = new SubjectNotifyListener();
+
+        Field field = AbstractSubjectCenter.class.getDeclaredField("OBSERVERS_MAP");
+        field.setAccessible(true);
+        OBSERVERS_MAP = (Map<String, List<Observer>>) field.get(AbstractSubjectCenter.class);
+    }
+
+    /**
+     * test register listener
+     */
+    @Test
+    public void testDefaultRegister() {
+        AbstractSubjectCenter.register(subjectNotifyListener);
+        List<Observer> list = OBSERVERS_MAP.get(AbstractSubjectCenter.SubjectType.SPRING_CONTENT_REFRESHED.name());
+        Assert.assertNotNull(list);
+        Assert.assertEquals(1, list.size());
+        Assert.assertSame(subjectNotifyListener, list.get(0));
+        OBSERVERS_MAP.clear();
+    }
+
+    /**
+     * test register listener
+     */
+    @Test
+    public void testSubjectTypeEnumRegister() {
+        AbstractSubjectCenter.register(AbstractSubjectCenter.SubjectType.THREAD_POOL_DYNAMIC_REFRESH, subjectNotifyListener);
+        List<Observer> list = OBSERVERS_MAP.get(AbstractSubjectCenter.SubjectType.THREAD_POOL_DYNAMIC_REFRESH.name());
+        Assert.assertNotNull(list);
+        Assert.assertEquals(1, list.size());
+        Assert.assertSame(subjectNotifyListener, list.get(0));
+        OBSERVERS_MAP.clear();
+    }
+
+    /**
+     * test register listener
+     */
+    @Test
+    public void testSubjectTypeNameRegister() {
+        AbstractSubjectCenter.register(AbstractSubjectCenter.SubjectType.THREAD_POOL_DYNAMIC_REFRESH.name(), subjectNotifyListener);
+        List<Observer> list = OBSERVERS_MAP.get(AbstractSubjectCenter.SubjectType.THREAD_POOL_DYNAMIC_REFRESH.name());
+        Assert.assertNotNull(list);
+        Assert.assertEquals(1, list.size());
+        Assert.assertSame(subjectNotifyListener, list.get(0));
+        OBSERVERS_MAP.clear();
+    }
+
+    /**
+     * test remove listener
+     */
+    @Test
+    public void testDefaultRemoveListener() {
+        AbstractSubjectCenter.register(subjectNotifyListener);
+        List<Observer> list = OBSERVERS_MAP.get(AbstractSubjectCenter.SubjectType.SPRING_CONTENT_REFRESHED.name());
+        Assert.assertNotNull(list);
+        Assert.assertEquals(1, list.size());
+        Assert.assertSame(subjectNotifyListener, list.get(0));
+
+        AbstractSubjectCenter.remove(subjectNotifyListener);
+        Assert.assertEquals(0, list.size());
+    }
+
+    /**
+     * test remove listener
+     */
+    @Test
+    public void testRemoveSubjectTypeNameListener() {
+        AbstractSubjectCenter.register(AbstractSubjectCenter.SubjectType.THREAD_POOL_DYNAMIC_REFRESH, subjectNotifyListener);
+        List<Observer> list = OBSERVERS_MAP.get(AbstractSubjectCenter.SubjectType.THREAD_POOL_DYNAMIC_REFRESH.name());
+        Assert.assertNotNull(list);
+        Assert.assertEquals(1, list.size());
+        Assert.assertSame(subjectNotifyListener, list.get(0));
+
+        AbstractSubjectCenter.remove(AbstractSubjectCenter.SubjectType.THREAD_POOL_DYNAMIC_REFRESH.name(), subjectNotifyListener);
+        Assert.assertEquals(0, list.size());
+    }
+
+    /**
+     * test notify
+     */
+    @Test
+    public void testNotifyBySubjectType() {
+        AbstractSubjectCenter.register(subjectNotifyListener);
+        List<Observer> list = OBSERVERS_MAP.get(AbstractSubjectCenter.SubjectType.SPRING_CONTENT_REFRESHED.name());
+        Assert.assertNotNull(list);
+
+        NotifyMessage notifyMessage = new NotifyMessage();
+        Assert.assertEquals(0, notifyMessage.getCount().get());
+        AbstractSubjectCenter.notify(AbstractSubjectCenter.SubjectType.SPRING_CONTENT_REFRESHED, () -> notifyMessage);
+        Assert.assertEquals(1, notifyMessage.getCount().get());
+        OBSERVERS_MAP.clear();
+    }
+
+    /**
+     * test notify
+     */
+    @Test
+    public void testNotifyBySubjectTypeName() {
+        AbstractSubjectCenter.register(subjectNotifyListener);
+        List<Observer> list = OBSERVERS_MAP.get(AbstractSubjectCenter.SubjectType.SPRING_CONTENT_REFRESHED.name());
+        Assert.assertNotNull(list);
+
+        NotifyMessage notifyMessage = new NotifyMessage();
+        Assert.assertEquals(0, notifyMessage.getCount().get());
+        AbstractSubjectCenter.notify(AbstractSubjectCenter.SubjectType.SPRING_CONTENT_REFRESHED.name(), () -> notifyMessage);
+        Assert.assertEquals(1, notifyMessage.getCount().get());
+        OBSERVERS_MAP.clear();
+    }
+
+    @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();
+        }
+    }
+}