refactor : Update api-gateway pattern (#2910)

Co-authored-by: rleontiev <rleontiev@i-novus.ru>

api-gateway/price-microservice/src/main/java/com/iluwatar/price/microservice/PriceController.java

@@ -24,7 +24,7 @@
  */
 package com.iluwatar.price.microservice;
 
-import lombok.extern.slf4j.Slf4j;
+import lombok.RequiredArgsConstructor;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.RestController;
 
@@ -32,10 +32,12 @@ import org.springframework.web.bind.annotation.RestController;
 /**
  * Exposes the Price microservice's endpoints.
  */
-@Slf4j
 @RestController
+@RequiredArgsConstructor
 public class PriceController {
 
+  private final PriceService priceService;
+
   /**
    * An endpoint for a user to retrieve a product's price.
    *
@@ -43,7 +45,6 @@ public class PriceController {
    */
   @GetMapping("/price")
   public String getPrice() {
-    LOGGER.info("Successfully found price info");
-    return "20";
+    return priceService.getPrice();
   }
 }

api-gateway/price-microservice/src/main/java/com/iluwatar/price/microservice/PriceService.java

@@ -0,0 +1,38 @@
+/*
+ * This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt).
+ *
+ * The MIT License
+ * Copyright © 2014-2022 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package com.iluwatar.price.microservice;
+
+/**
+ * Service to get a product's price.
+ */
+public interface PriceService {
+
+  /**
+   * Getting the price of a product.
+   *
+   * @return A product's price
+   */
+  String getPrice();
+}

api-gateway/price-microservice/src/main/java/com/iluwatar/price/microservice/PriceServiceImpl.java

@@ -0,0 +1,45 @@
+/*
+ * This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt).
+ *
+ * The MIT License
+ * Copyright © 2014-2022 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package com.iluwatar.price.microservice;
+
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.stereotype.Service;
+
+/**
+ * {@inheritDoc}
+ */
+@Service
+@Slf4j
+public class PriceServiceImpl implements PriceService {
+
+  /**
+   * {@inheritDoc}
+   */
+  @Override
+  public String getPrice() {
+    LOGGER.info("Successfully found price info");
+    return "20";
+  }
+}

api-gateway/price-microservice/src/test/java/com/iluwatar/price/microservice/PriceControllerTest.java

@@ -34,8 +34,8 @@ import static org.junit.jupiter.api.Assertions.assertEquals;
 class PriceControllerTest {
 
   @Test
-  void testgetPrice() {
-    var priceController = new PriceController();
+  void getPriceTest() {
+    var priceController = new PriceController(new PriceServiceImpl());
     var price = priceController.getPrice();
     assertEquals("20", price);
   }

api-gateway/price-microservice/src/test/java/com/iluwatar/price/microservice/PriceServiceTest.java

@@ -0,0 +1,42 @@
+/*
+ * This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt).
+ *
+ * The MIT License
+ * Copyright © 2014-2022 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package com.iluwatar.price.microservice;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+/**
+ * Test for Price Service
+ */
+class PriceServiceTest {
+
+  @Test
+  void getPriceTest() {
+    var priceService = new PriceServiceImpl();
+    var price = priceService.getPrice();
+    assertEquals("20", price);
+  }
+}