fix : supplement unit test for ThreadPoolManager (#805)

hippo4j-common/src/main/java/cn/hippo4j/common/executor/ThreadPoolManager.java

@@ -42,6 +42,9 @@ public class ThreadPoolManager {
         return INSTANCE;
     }
 
+    private ThreadPoolManager() {
+    }
+
     static {
         INSTANCE.init();
     }

hippo4j-common/src/test/java/cn/hippo4j/common/executor/ThreadPoolManagerTest.java

@@ -17,5 +17,59 @@
 
 package cn.hippo4j.common.executor;
 
-public final class ThreadPoolManagerTest {
+
+import cn.hippo4j.common.toolkit.ReflectUtil;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+
+public class ThreadPoolManagerTest {
+
+    // tenantId =  schedule，group = schedule
+    ScheduledExecutorService executorService1 = Executors.newScheduledThreadPool(1);
+
+    // tenantId =  schedule，group = schedule
+    ScheduledExecutorService executorService2 = Executors.newScheduledThreadPool(10);
+
+    // tenantId =  executor，group = executor
+    ExecutorService executorService3 = Executors.newFixedThreadPool(8);
+
+    // tenantId =  executor，group = executor
+    ExecutorService executorService4 = Executors.newFixedThreadPool(16);
+
+    static final String schedule = "schedule";
+
+    static final String executor = "executor";
+
+    @Test
+    public void getInstance() {
+        ThreadPoolManager poolManager = ThreadPoolManager.getInstance();
+        Assert.assertNotNull(poolManager);
+    }
+
+    @Test
+    public void register() {
+        ThreadPoolManager poolManager = ThreadPoolManager.getInstance();
+        poolManager.register(schedule, schedule, executorService1);
+        poolManager.register(schedule, schedule, executorService2);
+        poolManager.register(executor, executor, executorService3);
+        poolManager.register(executor, executor, executorService4);
+
+        Map<String, Map<String, Set<ExecutorService>>> manager = (Map<String, Map<String, Set<ExecutorService>>>) ReflectUtil.getFieldValue(poolManager, "resourcesManager");
+
+        Map<String, Set<ExecutorService>> scheduleMap = manager.get(schedule);
+        Assert.assertEquals(1, scheduleMap.size());
+        Set<ExecutorService> scheduleSet = scheduleMap.get(schedule);
+        Assert.assertEquals(2, scheduleSet.size());
+
+        Map<String, Set<ExecutorService>> executorMap = manager.get(executor);
+        Assert.assertEquals(1, executorMap.size());
+        Set<ExecutorService> executorSet = executorMap.get(executor);
+        Assert.assertEquals(2, executorSet.size());
+    }
 }