Java 11 migration: patterns starting with a (#1084)

* Moves abstract-factory pattern to java 11

* Moves abstract-document pattern to java 11

* Moves acyclic-visitor pattern to java 11

* Moves adapter pattern to java 11

* Moves aggregator-microservices pattern to java 11

* Moves api-gateway pattern to java 11

abstract-document/src/main/java/com/iluwatar/abstractdocument/AbstractDocument.java

@@ -23,10 +23,10 @@
 
 package com.iluwatar.abstractdocument;
 
+import java.util.Collection;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
-import java.util.Optional;
 import java.util.function.Function;
 import java.util.stream.Stream;
 
@@ -55,9 +55,13 @@ public abstract class AbstractDocument implements Document {
 
   @Override
   public <T> Stream<T> children(String key, Function<Map<String, Object>, T> constructor) {
-    Optional<List<Map<String, Object>>> any = Stream.of(get(key)).filter(Objects::nonNull)
+    return Stream.ofNullable(get(key))
-        .map(el -> (List<Map<String, Object>>) el).findAny();
+        .filter(Objects::nonNull)
-    return any.map(maps -> maps.stream().map(constructor)).orElseGet(Stream::empty);
+        .map(el -> (List<Map<String, Object>>) el)
+        .findAny()
+        .stream()
+        .flatMap(Collection::stream)
+        .map(constructor);
   }
 
   @Override

abstract-document/src/main/java/com/iluwatar/abstractdocument/App.java

@@ -66,11 +66,14 @@ public class App {
     var car = new Car(carProperties);
 
     LOGGER.info("Here is our car:");
-    LOGGER.info("-> model: {}", car.getModel().get());
+    LOGGER.info("-> model: {}", car.getModel().orElseThrow());
-    LOGGER.info("-> price: {}", car.getPrice().get());
+    LOGGER.info("-> price: {}", car.getPrice().orElseThrow());
     LOGGER.info("-> parts: ");
-    car.getParts().forEach(p -> LOGGER
+    car.getParts().forEach(p -> LOGGER.info("\t{}/{}/{}",
-        .info("\t{}/{}/{}", p.getType().get(), p.getModel().get(), p.getPrice().get()));
+        p.getType().orElse(null),
+        p.getModel().orElse(null),
+        p.getPrice().orElse(null))
+    );
   }
 
   /**

abstract-document/src/test/java/com/iluwatar/abstractdocument/AbstractDocumentTest.java

@@ -23,14 +23,14 @@
 
 package com.iluwatar.abstractdocument;
 
-import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.stream.Stream;
+import org.junit.jupiter.api.Test;
-
-import static org.junit.jupiter.api.Assertions.*;
 
 /**
  * AbstractDocument test class
@@ -61,22 +61,22 @@ public class AbstractDocumentTest {
 
     document.put(KEY, children);
 
-    Stream<DocumentImplementation> childrenStream = document.children(KEY, DocumentImplementation::new);
+    var childrenStream = document.children(KEY, DocumentImplementation::new);
     assertNotNull(children);
     assertEquals(2, childrenStream.count());
   }
 
   @Test
   public void shouldRetrieveEmptyStreamForNonExistingChildren() {
-    Stream<DocumentImplementation> children = document.children(KEY, DocumentImplementation::new);
+    var children = document.children(KEY, DocumentImplementation::new);
     assertNotNull(children);
     assertEquals(0, children.count());
   }
 
   @Test
   public void shouldIncludePropsInToString() {
-    Map<String, Object> props = Map.of(KEY, VALUE);
+    var props = Map.of(KEY, (Object) VALUE);
-    DocumentImplementation document = new DocumentImplementation(props);
+    var document = new DocumentImplementation(props);
     assertTrue(document.toString().contains(KEY));
     assertTrue(document.toString().contains(VALUE));
   }

abstract-document/src/test/java/com/iluwatar/abstractdocument/DomainTest.java

@@ -23,15 +23,14 @@
 
 package com.iluwatar.abstractdocument;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
 import com.iluwatar.abstractdocument.domain.Car;
 import com.iluwatar.abstractdocument.domain.Part;
 import com.iluwatar.abstractdocument.domain.enums.Property;
-import org.junit.jupiter.api.Test;
-
 import java.util.List;
 import java.util.Map;
-
+import org.junit.jupiter.api.Test;
-import static org.junit.jupiter.api.Assertions.assertEquals;
 
 /**
  * Test for Part and Car
@@ -47,27 +46,27 @@ public class DomainTest {
 
   @Test
   public void shouldConstructPart() {
-    Map<String, Object> partProperties = Map.of(
+    var partProperties = Map.of(
-            Property.TYPE.toString(), TEST_PART_TYPE,
+        Property.TYPE.toString(), TEST_PART_TYPE,
-            Property.MODEL.toString(), TEST_PART_MODEL,
+        Property.MODEL.toString(), TEST_PART_MODEL,
-            Property.PRICE.toString(), TEST_PART_PRICE);
+        Property.PRICE.toString(), (Object) TEST_PART_PRICE
-    Part part = new Part(partProperties);
+    );
-
+    var part = new Part(partProperties);
-    assertEquals(TEST_PART_TYPE, part.getType().get());
+    assertEquals(TEST_PART_TYPE, part.getType().orElseThrow());
-    assertEquals(TEST_PART_MODEL, part.getModel().get());
+    assertEquals(TEST_PART_MODEL, part.getModel().orElseThrow());
-    assertEquals(TEST_PART_PRICE, part.getPrice().get());
+    assertEquals(TEST_PART_PRICE, part.getPrice().orElseThrow());
   }
 
   @Test
   public void shouldConstructCar() {
-    Map<String, Object> carProperties = Map.of(
+    var carProperties = Map.of(
-            Property.MODEL.toString(), TEST_CAR_MODEL,
+        Property.MODEL.toString(), TEST_CAR_MODEL,
-            Property.PRICE.toString(), TEST_CAR_PRICE,
+        Property.PRICE.toString(), TEST_CAR_PRICE,
-            Property.PARTS.toString(), List.of(Map.of(), Map.of()));
+        Property.PARTS.toString(), List.of(Map.of(), Map.of())
-    Car car = new Car(carProperties);
+    );
-
+    var car = new Car(carProperties);
-    assertEquals(TEST_CAR_MODEL, car.getModel().get());
+    assertEquals(TEST_CAR_MODEL, car.getModel().orElseThrow());
-    assertEquals(TEST_CAR_PRICE, car.getPrice().get());
+    assertEquals(TEST_CAR_PRICE, car.getPrice().orElseThrow());
     assertEquals(2, car.getParts().count());
   }
 

abstract-factory/README.md

@@ -109,10 +109,10 @@ public class OrcKingdomFactory implements KingdomFactory {
 Now we have our abstract factory that lets us make family of related objects i.e. Elven kingdom factory creates Elven castle, king and army etc.
 
 ```java
-KingdomFactory factory = new ElfKingdomFactory();
+var factory = new ElfKingdomFactory();
-Castle castle = factory.createCastle();
+var castle = factory.createCastle();
-King king = factory.createKing();
+var king = factory.createKing();
-Army army = factory.createArmy();
+var army = factory.createArmy();
 
 castle.getDescription();  // Output: This is the Elven castle!
 king.getDescription(); // Output: This is the Elven king!
@@ -143,7 +143,7 @@ public static class FactoryMaker {
 }
 
 public static void main(String[] args) {
-  App app = new App();
+  var app = new App();
 
   LOGGER.info("Elf Kingdom");
   app.createKingdom(FactoryMaker.makeFactory(KingdomType.ELF));

abstract-factory/src/main/java/com/iluwatar/abstractfactory/App.java

@@ -128,7 +128,7 @@ public class App {
    */
   public static void main(String[] args) {
 
-    App app = new App();
+    var app = new App();
 
     LOGGER.info("Elf Kingdom");
     app.createKingdom(FactoryMaker.makeFactory(KingdomType.ELF));

abstract-factory/src/test/java/com/iluwatar/abstractfactory/AbstractFactoryTest.java

@@ -28,7 +28,6 @@ import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import com.iluwatar.abstractfactory.App.FactoryMaker;
 import com.iluwatar.abstractfactory.App.FactoryMaker.KingdomType;
-
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
@@ -49,30 +48,30 @@ public class AbstractFactoryTest {
 
   @Test
   public void king() {
-    final King elfKing = app.getKing(elfFactory);
+    final var elfKing = app.getKing(elfFactory);
     assertTrue(elfKing instanceof ElfKing);
     assertEquals(ElfKing.DESCRIPTION, elfKing.getDescription());
-    final King orcKing = app.getKing(orcFactory);
+    final var orcKing = app.getKing(orcFactory);
     assertTrue(orcKing instanceof OrcKing);
     assertEquals(OrcKing.DESCRIPTION, orcKing.getDescription());
   }
 
   @Test
   public void castle() {
-    final Castle elfCastle = app.getCastle(elfFactory);
+    final var elfCastle = app.getCastle(elfFactory);
     assertTrue(elfCastle instanceof ElfCastle);
     assertEquals(ElfCastle.DESCRIPTION, elfCastle.getDescription());
-    final Castle orcCastle = app.getCastle(orcFactory);
+    final var orcCastle = app.getCastle(orcFactory);
     assertTrue(orcCastle instanceof OrcCastle);
     assertEquals(OrcCastle.DESCRIPTION, orcCastle.getDescription());
   }
 
   @Test
   public void army() {
-    final Army elfArmy = app.getArmy(elfFactory);
+    final var elfArmy = app.getArmy(elfFactory);
     assertTrue(elfArmy instanceof ElfArmy);
     assertEquals(ElfArmy.DESCRIPTION, elfArmy.getDescription());
-    final Army orcArmy = app.getArmy(orcFactory);
+    final var orcArmy = app.getArmy(orcFactory);
     assertTrue(orcArmy instanceof OrcArmy);
     assertEquals(OrcArmy.DESCRIPTION, orcArmy.getDescription());
   }
@@ -80,9 +79,9 @@ public class AbstractFactoryTest {
   @Test
   public void createElfKingdom() {
     app.createKingdom(elfFactory);
-    final King king = app.getKing();
+    final var king = app.getKing();
-    final Castle castle = app.getCastle();
+    final var castle = app.getCastle();
-    final Army army = app.getArmy();
+    final var army = app.getArmy();
     assertTrue(king instanceof ElfKing);
     assertEquals(ElfKing.DESCRIPTION, king.getDescription());
     assertTrue(castle instanceof ElfCastle);
@@ -94,9 +93,9 @@ public class AbstractFactoryTest {
   @Test
   public void createOrcKingdom() {
     app.createKingdom(orcFactory);
-    final King king = app.getKing();
+    final var king = app.getKing();
-    final Castle castle = app.getCastle();
+    final var castle = app.getCastle();
-    final Army army = app.getArmy();
+    final var army = app.getArmy();
     assertTrue(king instanceof OrcKing);
     assertEquals(OrcKing.DESCRIPTION, king.getDescription());
     assertTrue(castle instanceof OrcCastle);

abstract-factory/src/test/java/com/iluwatar/abstractfactory/AppTest.java

@@ -25,15 +25,12 @@ package com.iluwatar.abstractfactory;
 
 import org.junit.jupiter.api.Test;
 
-import java.io.IOException;
-
 /**
  * Tests that Abstract Factory example runs without errors.
  */
 public class AppTest {
   @Test
-  public void test() throws IOException {
+  public void test() {
-    String[] args = {};
+    App.main(new String[]{});
-    App.main(args);
   }
 }

acyclic-visitor/src/test/java/com/iluwatar/acyclicvisitor/AppTest.java

@@ -25,16 +25,13 @@ package com.iluwatar.acyclicvisitor;
 
 import org.junit.jupiter.api.Test;
 
-import com.iluwatar.acyclicvisitor.App;
-
 /**
  * Tests that the Acyclic Visitor example runs without errors.
  */
 public class AppTest {
-  
+
   @Test
   public void test() {
-    String[] args = {};
+    App.main(new String[]{});
-    App.main(args);  
   }
 }

acyclic-visitor/src/test/java/com/iluwatar/acyclicvisitor/ConfigureForDosVisitorTest.java

@@ -37,7 +37,7 @@ import uk.org.lidalia.slf4jtest.TestLoggerFactory;
  */
 public class ConfigureForDosVisitorTest {
 
-  TestLogger logger = TestLoggerFactory.getTestLogger(ConfigureForDosVisitor.class);
+  private TestLogger logger = TestLoggerFactory.getTestLogger(ConfigureForDosVisitor.class);
   
   @Test
   public void testVisitForZoom() {    
@@ -46,19 +46,21 @@ public class ConfigureForDosVisitorTest {
     
     conDos.visit(zoom);
     
-    assertThat(logger.getLoggingEvents()).extracting("level", "message").contains(
+    assertThat(logger.getLoggingEvents())
-        tuple(INFO, zoom + " used with Dos configurator."));
+        .extracting("level", "message")
+        .contains(tuple(INFO, zoom + " used with Dos configurator."));
   }
   
   @Test
   public void testVisitForHayes() {
-    ConfigureForDosVisitor conDos = new ConfigureForDosVisitor();
+    var conDos = new ConfigureForDosVisitor();
-    Hayes hayes = new Hayes();
+    var hayes = new Hayes();
     
     conDos.visit(hayes);
     
-    assertThat(logger.getLoggingEvents()).extracting("level", "message").contains(
+    assertThat(logger.getLoggingEvents())
-        tuple(INFO, hayes + " used with Dos configurator."));
+        .extracting("level", "message")
+        .contains(tuple(INFO, hayes + " used with Dos configurator."));
   }
   
   @AfterEach

acyclic-visitor/src/test/java/com/iluwatar/acyclicvisitor/ConfigureForUnixVisitorTest.java

@@ -52,7 +52,8 @@ public class ConfigureForUnixVisitorTest {
     
     conUnix.visit(zoom);
     
-    assertThat(LOGGER.getLoggingEvents()).extracting("level", "message").contains(
+    assertThat(LOGGER.getLoggingEvents())
-        tuple(INFO, zoom + " used with Unix configurator."));
+        .extracting("level", "message")
+        .contains(tuple(INFO, zoom + " used with Unix configurator."));
   }
 }

adapter/README.md

@@ -93,7 +93,7 @@ public class FishingBoatAdapter implements RowingBoat {
 And now the `Captain` can use the `FishingBoat` to escape the pirates.
 
 ```java
-Captain captain = new Captain(new FishingBoatAdapter());
+var captain = new Captain(new FishingBoatAdapter());
 captain.row();
 ```
 

adapter/src/test/java/com/iluwatar/adapter/AdapterPatternTest.java

@@ -23,18 +23,16 @@
 
 package com.iluwatar.adapter;
 
-import org.junit.jupiter.api.BeforeEach;
-import org.junit.jupiter.api.Test;
-
-import java.util.HashMap;
-import java.util.Map;
-
 import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.verify;
 
+import java.util.HashMap;
+import java.util.Map;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
 /**
  * Test class
- * 
  */
 public class AdapterPatternTest {
 
@@ -51,7 +49,7 @@ public class AdapterPatternTest {
   public void setup() {
     beans = new HashMap<>();
 
-    FishingBoatAdapter fishingBoatAdapter = spy(new FishingBoatAdapter());
+    var fishingBoatAdapter = spy(new FishingBoatAdapter());
     beans.put(FISHING_BEAN, fishingBoatAdapter);
 
     var captain = new Captain();
@@ -60,10 +58,10 @@ public class AdapterPatternTest {
   }
 
   /**
-   * This test asserts that when we use the row() method on a captain bean(client), it is
+   * This test asserts that when we use the row() method on a captain bean(client), it is internally
-   * internally calling sail method on the fishing boat object. The Adapter ({@link FishingBoatAdapter}
+   * calling sail method on the fishing boat object. The Adapter ({@link FishingBoatAdapter} )
-   * ) converts the interface of the target class ( {@link FishingBoat}) into a suitable one
+   * converts the interface of the target class ( {@link FishingBoat}) into a suitable one expected
-   * expected by the client ({@link Captain} ).
+   * by the client ({@link Captain} ).
    */
   @Test
   public void testAdapter() {

adapter/src/test/java/com/iluwatar/adapter/AppTest.java

@@ -25,15 +25,12 @@ package com.iluwatar.adapter;
 
 import org.junit.jupiter.api.Test;
 
-import java.io.IOException;
-
 /**
  * Tests that Adapter example runs without errors.
  */
 public class AppTest {
   @Test
-  public void test() throws IOException {
+  public void test() {
-    String[] args = {};
+    App.main(new String[]{});
-    App.main(args);
   }
 }

aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/Aggregator.java

@@ -23,6 +23,8 @@
 
 package com.iluwatar.aggregator.microservices;
 
+import static java.util.Objects.requireNonNullElse;
+
 import javax.annotation.Resource;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RequestMethod;
@@ -52,20 +54,14 @@ public class Aggregator {
   public Product getProduct() {
 
     var product = new Product();
-    String productTitle = informationClient.getProductTitle();
+    var productTitle = informationClient.getProductTitle();
-    Integer productInventory = inventoryClient.getProductInventories();
+    var productInventory = inventoryClient.getProductInventories();
 
-    if (productTitle != null) {
+    //Fallback to error message
-      product.setTitle(productTitle);
+    product.setTitle(requireNonNullElse(productTitle, "Error: Fetching Product Title Failed"));
-    } else {
-      product.setTitle("Error: Fetching Product Title Failed"); //Fallback to error message
-    }
 
-    if (productInventory != null) {
+    //Fallback to default error inventory
-      product.setProductInventories(productInventory);
+    product.setProductInventories(requireNonNullElse(productInventory, -1));
-    } else {
-      product.setProductInventories(-1); //Fallback to default error inventory
-    }
 
     return product;
   }

aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/ProductInformationClientImpl.java

@@ -42,19 +42,19 @@ public class ProductInformationClientImpl implements ProductInformationClient {
 
   @Override
   public String getProductTitle() {
-    String response = null;
+    var request = HttpRequest.newBuilder()
-    var request =
+        .GET()
-        HttpRequest.newBuilder().GET().uri(URI.create("http://localhost:51515/information"))
+        .uri(URI.create("http://localhost:51515/information"))
-            .build();
+        .build();
     var client = HttpClient.newHttpClient();
     try {
       var httpResponse = client.send(request, HttpResponse.BodyHandlers.ofString());
-      response = httpResponse.body();
+      return httpResponse.body();
     } catch (IOException ioe) {
       LOGGER.error("IOException Occurred", ioe);
     } catch (InterruptedException ie) {
       LOGGER.error("InterruptedException Occurred", ie);
     }
-    return response;
+    return null;
   }
 }

aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/ProductInventoryClientImpl.java

@@ -44,9 +44,10 @@ public class ProductInventoryClientImpl implements ProductInventoryClient {
   public Integer getProductInventories() {
     var response = "";
 
-    var request =
+    var request = HttpRequest.newBuilder()
-        HttpRequest.newBuilder().GET().uri(URI.create("http://localhost:51516/inventories"))
+        .GET()
-            .build();
+        .uri(URI.create("http://localhost:51516/inventories"))
+        .build();
     var client = HttpClient.newHttpClient();
     try {
       var httpResponse = client.send(request, HttpResponse.BodyHandlers.ofString());

aggregator-microservices/aggregator-service/src/test/java/com/iluwatar/aggregator/microservices/AggregatorTest.java

@@ -56,13 +56,13 @@ public class AggregatorTest {
    */
   @Test
   public void testGetProduct() {
-    String title = "The Product Title.";
+    var title = "The Product Title.";
-    int inventories = 5;
+    var inventories = 5;
 
     when(informationClient.getProductTitle()).thenReturn(title);
     when(inventoryClient.getProductInventories()).thenReturn(inventories);
 
-    Product testProduct = aggregator.getProduct();
+    var testProduct = aggregator.getProduct();
 
     assertEquals(title, testProduct.getTitle());
     assertEquals(inventories, testProduct.getProductInventories());

aggregator-microservices/information-microservice/src/test/java/com/iluwatar/information/microservice/InformationControllerTest.java

@@ -34,10 +34,8 @@ public class InformationControllerTest {
 
   @Test
   public void shouldGetProductTitle() {
-    InformationController infoController = new InformationController();
+    var infoController = new InformationController();
-
+    var title = infoController.getProductTitle();
-    String title = infoController.getProductTitle();
-
     assertEquals("The Product Title.", title);
   }
 

aggregator-microservices/inventory-microservice/src/test/java/com/iluwatar/inventory/microservice/InventoryControllerTest.java

@@ -33,10 +33,8 @@ import org.junit.jupiter.api.Test;
 public class InventoryControllerTest {
   @Test
   public void testGetProductInventories() {
-    InventoryController inventoryController = new InventoryController();
+    var inventoryController = new InventoryController();
-
+    var numberOfInventories = inventoryController.getProductInventories();
-    int numberOfInventories = inventoryController.getProductInventories();
-
     assertEquals(5, numberOfInventories);
   }
 }

api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/ApiGateway.java

@@ -47,7 +47,7 @@ public class ApiGateway {
    */
   @RequestMapping(path = "/desktop", method = RequestMethod.GET)
   public DesktopProduct getProductDesktop() {
-    DesktopProduct desktopProduct = new DesktopProduct();
+    var desktopProduct = new DesktopProduct();
     desktopProduct.setImagePath(imageClient.getImagePath());
     desktopProduct.setPrice(priceClient.getPrice());
     return desktopProduct;
@@ -60,7 +60,7 @@ public class ApiGateway {
    */
   @RequestMapping(path = "/mobile", method = RequestMethod.GET)
   public MobileProduct getProductMobile() {
-    MobileProduct mobileProduct = new MobileProduct();
+    var mobileProduct = new MobileProduct();
     mobileProduct.setPrice(priceClient.getPrice());
     return mobileProduct;
   }

api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/ImageClientImpl.java

@@ -27,7 +27,6 @@ import java.io.IOException;
 import java.net.URI;
 import java.net.http.HttpClient;
 import java.net.http.HttpRequest;
-import java.net.http.HttpResponse;
 import java.net.http.HttpResponse.BodyHandlers;
 import org.springframework.stereotype.Component;
 
@@ -43,21 +42,19 @@ public class ImageClientImpl implements ImageClient {
    */
   @Override
   public String getImagePath() {
-    String response = null;
+    var httpClient = HttpClient.newHttpClient();
-
+    var httpGet = HttpRequest.newBuilder()
-    HttpClient httpClient = HttpClient.newHttpClient();
+        .GET()
-    HttpRequest httpGet =
+        .uri(URI.create("http://localhost:50005/image-path"))
-        HttpRequest.newBuilder().GET().uri(URI.create("http://localhost:50005/image-path")).build();
+        .build();
 
     try {
-      HttpResponse<String> httpResponse = httpClient.send(httpGet, BodyHandlers.ofString());
+      var httpResponse = httpClient.send(httpGet, BodyHandlers.ofString());
-      response = httpResponse.body();
+      return httpResponse.body();
-    } catch (IOException e) {
+    } catch (IOException | InterruptedException e) {
-      e.printStackTrace();
-    } catch (InterruptedException e) {
       e.printStackTrace();
     }
 
-    return response;
+    return null;
   }
 }

api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/PriceClientImpl.java

@@ -27,7 +27,6 @@ import java.io.IOException;
 import java.net.URI;
 import java.net.http.HttpClient;
 import java.net.http.HttpRequest;
-import java.net.http.HttpResponse;
 import java.net.http.HttpResponse.BodyHandlers;
 import org.springframework.stereotype.Component;
 
@@ -43,22 +42,19 @@ public class PriceClientImpl implements PriceClient {
    */
   @Override
   public String getPrice() {
-
+    var httpClient = HttpClient.newHttpClient();
-    String response = null;
+    var httpGet = HttpRequest.newBuilder()
-
+        .GET()
-    HttpClient httpClient = HttpClient.newHttpClient();
+        .uri(URI.create("http://localhost:50006/price"))
-    HttpRequest httpGet =
+        .build();
-        HttpRequest.newBuilder().GET().uri(URI.create("http://localhost:50006/price")).build();
 
     try {
-      HttpResponse<String> httpResponse = httpClient.send(httpGet, BodyHandlers.ofString());
+      var httpResponse = httpClient.send(httpGet, BodyHandlers.ofString());
-      response = httpResponse.body();
+      return httpResponse.body();
-    } catch (IOException e) {
+    } catch (IOException | InterruptedException e) {
-      e.printStackTrace();
-    } catch (InterruptedException e) {
       e.printStackTrace();
     }
 
-    return response;
+    return null;
   }
 }

api-gateway/api-gateway-service/src/test/java/com/iluwatar/api/gateway/ApiGatewayTest.java

@@ -23,15 +23,15 @@
 
 package com.iluwatar.api.gateway;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.mockito.Mockito.when;
+
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.mockito.InjectMocks;
 import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.mockito.Mockito.when;
-
 /**
  * Test API Gateway Pattern
  */
@@ -56,12 +56,12 @@ public class ApiGatewayTest {
    */
   @Test
   public void testGetProductDesktop() {
-    String imagePath = "/product-image.png";
+    var imagePath = "/product-image.png";
-    String price = "20";
+    var price = "20";
     when(imageClient.getImagePath()).thenReturn(imagePath);
     when(priceClient.getPrice()).thenReturn(price);
 
-    DesktopProduct desktopProduct = apiGateway.getProductDesktop();
+    var desktopProduct = apiGateway.getProductDesktop();
 
     assertEquals(price, desktopProduct.getPrice());
     assertEquals(imagePath, desktopProduct.getImagePath());
@@ -72,10 +72,10 @@ public class ApiGatewayTest {
    */
   @Test
   public void testGetProductMobile() {
-    String price = "20";
+    var price = "20";
     when(priceClient.getPrice()).thenReturn(price);
 
-    MobileProduct mobileProduct = apiGateway.getProductMobile();
+    var mobileProduct = apiGateway.getProductMobile();
 
     assertEquals(price, mobileProduct.getPrice());
   }

api-gateway/image-microservice/src/test/java/com/iluwatar/image/microservice/ImageControllerTest.java

@@ -23,20 +23,18 @@
 
 package com.iluwatar.image.microservice;
 
-import org.junit.jupiter.api.Test;
-
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
+import org.junit.jupiter.api.Test;
+
 /**
  * Test for Image Rest Controller
  */
 public class ImageControllerTest {
   @Test
   public void testGetImagePath() {
-    ImageController imageController = new ImageController();
+    var imageController = new ImageController();
-
+    var imagePath = imageController.getImagePath();
-    String imagePath = imageController.getImagePath();
-
     assertEquals("/product-image.png", imagePath);
   }
 }

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

@@ -23,20 +23,18 @@
 
 package com.iluwatar.price.microservice;
 
-import org.junit.jupiter.api.Test;
-
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
+import org.junit.jupiter.api.Test;
+
 /**
  * Test for Price Rest Controller
  */
 public class PriceControllerTest {
   @Test
   public void testgetPrice() {
-    PriceController priceController = new PriceController();
+    var priceController = new PriceController();
-
+    var price = priceController.getPrice();
-    String price = priceController.getPrice();
-
     assertEquals("20", price);
   }
 }