[ISSUE#5695] Summer2021 add unit test for CryptoManager (#6989)

* add unit test for CryptoManager

* add unit test for CryptoManager

api/src/test/java/com/alibaba/nacos/api/config/CryptoManagerTest.java

@@ -0,0 +1,62 @@
+/*
+ *   Copyright 1999-2018 Alibaba Group Holding Ltd.
+ *
+ *   Licensed under the Apache License, Version 2.0 (the "License");
+ *   you may not use this file except in compliance with the License.
+ *   You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *   Unless required by applicable law or agreed to in writing, software
+ *   distributed under the License is distributed on an "AS IS" BASIS,
+ *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *   See the License for the specific language governing permissions and
+ *   limitations under the License.
+ */
+
+package com.alibaba.nacos.api.config;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * CryptoManagerTest.
+ *
+ * @author lixiaoshuang
+ */
+public class CryptoManagerTest {
+
+    @Test
+    public void testInstance() {
+        CryptoSpi rsa = CryptoManager.instance("rsa");
+        Assert.assertNull(rsa);
+    }
+
+    @Test
+    public void testJoin() {
+        CryptoSpi cryptoSpi = new CryptoSpi() {
+            @Override
+            public String encrypt(String secretKey, String content) {
+                return null;
+            }
+
+            @Override
+            public String decrypt(String secretKey, String content) {
+                return null;
+            }
+
+            @Override
+            public String generateSecretKey() {
+                return null;
+            }
+
+            @Override
+            public String named() {
+                return "aes";
+            }
+        };
+        CryptoManager.join(cryptoSpi);
+        CryptoSpi aes = CryptoManager.instance("aes");
+        Assert.assertNotNull(aes);
+    }
+}