Implement SMS sender factory to retrieve instance of SMS sender

components/sms-mgt/io.entgra.sms.mgt.core/src/main/java/io/entgra/sms/mgt/core/SMSSenderFactory.java

@@ -0,0 +1,71 @@
+/*
+ * Copyright (c) 2021, Entgra (Pvt) Ltd. (http://www.entgra.io) All Rights Reserved.
+ *
+ * Entgra (Pvt) Ltd. licenses this file to you 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 io.entgra.sms.mgt.core;
+
+import io.entgra.sms.mgt.common.config.SMSGateway;
+import io.entgra.sms.mgt.common.spi.SMSSender;
+import io.entgra.sms.mgt.core.config.SMSConfigurationManager;
+import org.apache.commons.lang.StringUtils;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+/**
+ * Factory class to retrieve the relevant SMSSender based on SMS Configuration.
+ * There can be multiple SMSSender Implementation and an instance of that specific SMSSender can be
+ * created and retrieved via this factory class.
+ */
+public class SMSSenderFactory {
+
+    private static final Log log = LogFactory.getLog(SMSSenderFactory.class);
+
+    /**
+     * Retrieve the SMSSender based on the default SMS Gateway in SMS configuration.
+     * @return an instance of {@link SMSSender}
+     */
+    public static SMSSender getSMSSender() {
+        SMSGateway smsGateway = SMSConfigurationManager.getInstance().getSMSConfig().getDefaultSMSGateway();
+        if (smsGateway != null) {
+            return getSMSSender(smsGateway.getExtensionClass());
+        }
+        return null;
+    }
+
+    /**
+     * Retrieve the SMSSender based on the provided extension class name.
+     * @param extensionClass has the class name of the implemented SMSSender using which
+     *                       an instance of SMSSender is created
+     * @return an instance of {@link SMSSender}
+     */
+    public static SMSSender getSMSSender(String extensionClass) {
+        if (StringUtils.isNotBlank(extensionClass)) {
+            try {
+                Class<?> clz = Class.forName(extensionClass);
+                return (SMSSender) clz.newInstance();
+            } catch (ClassNotFoundException e) {
+                log.error("Extension class '" + extensionClass + "' cannot be located", e);
+            } catch (IllegalAccessException e) {
+                log.error("Can't access  the class '" + extensionClass
+                        + "' or its nullary constructor is not accessible", e);
+            } catch (InstantiationException e) {
+                log.error("Extension class '" + extensionClass + "' instantiation is failed", e);
+            }
+        }
+        return null;
+    }
+}