re-sync from base

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

@@ -23,15 +23,15 @@
 
 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;
 
 /**
- * Abstract implementation of Document interface
+ * Abstract implementation of Document interface.
  */
 public abstract class AbstractDocument implements Document {
 
@@ -55,16 +55,21 @@ public Object get(String key) {
 
   @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)
-        .map(el -> (List<Map<String, Object>>) el).findAny();
-    return any.map(maps -> maps.stream().map(constructor)).orElseGet(Stream::empty);
+    return Stream.ofNullable(get(key))
+        .filter(Objects::nonNull)
+        .map(el -> (List<Map<String, Object>>) el)
+        .findAny()
+        .stream()
+        .flatMap(Collection::stream)
+        .map(constructor);
   }
 
   @Override
   public String toString() {
     var builder = new StringBuilder();
     builder.append(getClass().getName()).append("[");
-    properties.forEach((key, value) -> builder.append("[").append(key).append(" : ").append(value).append("]"));
+    properties.forEach((key, value) -> builder.append("[").append(key).append(" : ").append(value)
+        .append("]"));
     builder.append("]");
     return builder.toString();
   }

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

@@ -25,58 +25,59 @@
 
 import com.iluwatar.abstractdocument.domain.Car;
 import com.iluwatar.abstractdocument.domain.enums.Property;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 import java.util.List;
 import java.util.Map;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
- * The Abstract Document pattern enables handling additional, non-static
- * properties. This pattern uses concept of traits to enable type safety and
- * separate properties of different classes into set of interfaces.
- * <p>
- * <p>
- * In Abstract Document pattern,({@link AbstractDocument}) fully implements
- * {@link Document}) interface. Traits are then defined to enable access to
- * properties in usual, static way.
+ * The Abstract Document pattern enables handling additional, non-static properties. This pattern
+ * uses concept of traits to enable type safety and separate properties of different classes into
+ * set of interfaces.
+ *
+ * <p>In Abstract Document pattern,({@link AbstractDocument}) fully implements {@link Document})
+ * interface. Traits are then defined to enable access to properties in usual, static way.
  */
 public class App {
 
   private static final Logger LOGGER = LoggerFactory.getLogger(App.class);
 
   /**
-   * Executes the App
+   * Executes the App.
    */
   public App() {
     LOGGER.info("Constructing parts and car");
 
     var wheelProperties = Map.of(
-            Property.TYPE.toString(), "wheel",
-            Property.MODEL.toString(), "15C",
-            Property.PRICE.toString(), 100L);
+        Property.TYPE.toString(), "wheel",
+        Property.MODEL.toString(), "15C",
+        Property.PRICE.toString(), 100L);
 
     var doorProperties = Map.of(
-            Property.TYPE.toString(), "door",
-            Property.MODEL.toString(), "Lambo",
-            Property.PRICE.toString(), 300L);
+        Property.TYPE.toString(), "door",
+        Property.MODEL.toString(), "Lambo",
+        Property.PRICE.toString(), 300L);
 
     var carProperties = Map.of(
-            Property.MODEL.toString(), "300SL",
-            Property.PRICE.toString(), 10000L,
-            Property.PARTS.toString(), List.of(wheelProperties, doorProperties));
+        Property.MODEL.toString(), "300SL",
+        Property.PRICE.toString(), 10000L,
+        Property.PARTS.toString(), List.of(wheelProperties, doorProperties));
 
     var car = new Car(carProperties);
 
     LOGGER.info("Here is our car:");
-    LOGGER.info("-> model: {}", car.getModel().get());
-    LOGGER.info("-> price: {}", car.getPrice().get());
+    LOGGER.info("-> model: {}", car.getModel().orElseThrow());
+    LOGGER.info("-> price: {}", car.getPrice().orElseThrow());
     LOGGER.info("-> parts: ");
-    car.getParts().forEach(p -> LOGGER.info("\t{}/{}/{}", p.getType().get(), p.getModel().get(), p.getPrice().get()));
+    car.getParts().forEach(p -> LOGGER.info("\t{}/{}/{}",
+        p.getType().orElse(null),
+        p.getModel().orElse(null),
+        p.getPrice().orElse(null))
+    );
   }
 
   /**
-   * Program entry point
+   * Program entry point.
    *
    * @param args command line args
    */

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

@@ -28,12 +28,12 @@
 import java.util.stream.Stream;
 
 /**
- * Document interface
+ * Document interface.
  */
 public interface Document {
 
   /**
-   * Puts the value related to the key
+   * Puts the value related to the key.
    *
    * @param key   element key
    * @param value element value
@@ -42,15 +42,15 @@ public interface Document {
   Void put(String key, Object value);
 
   /**
-   * Gets the value for the key
+   * Gets the value for the key.
    *
    * @param key element key
    * @return value or null
    */
   Object get(String key);
 
   /**
-   * Gets the stream of child documents
+   * Gets the stream of child documents.
    *
    * @param key         element key
    * @param constructor constructor of child class

abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/Car.java

@@ -23,12 +23,11 @@
 
 package com.iluwatar.abstractdocument.domain;
 
-import java.util.Map;
-
 import com.iluwatar.abstractdocument.AbstractDocument;
+import java.util.Map;
 
 /**
- * Car entity
+ * Car entity.
  */
 public class Car extends AbstractDocument implements HasModel, HasPrice, HasParts {
 

abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/HasModel.java

@@ -23,13 +23,12 @@
 
 package com.iluwatar.abstractdocument.domain;
 
-import java.util.Optional;
-
 import com.iluwatar.abstractdocument.Document;
 import com.iluwatar.abstractdocument.domain.enums.Property;
+import java.util.Optional;
 
 /**
- * HasModel trait for static access to 'model' property
+ * HasModel trait for static access to 'model' property.
  */
 public interface HasModel extends Document {
 

abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/HasParts.java

@@ -23,13 +23,12 @@
 
 package com.iluwatar.abstractdocument.domain;
 
-import java.util.stream.Stream;
-
 import com.iluwatar.abstractdocument.Document;
 import com.iluwatar.abstractdocument.domain.enums.Property;
+import java.util.stream.Stream;
 
 /**
- * HasParts trait for static access to 'parts' property
+ * HasParts trait for static access to 'parts' property.
  */
 public interface HasParts extends Document {
 

abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/HasPrice.java

@@ -23,13 +23,12 @@
 
 package com.iluwatar.abstractdocument.domain;
 
-import java.util.Optional;
-
 import com.iluwatar.abstractdocument.Document;
 import com.iluwatar.abstractdocument.domain.enums.Property;
+import java.util.Optional;
 
 /**
- * HasPrice trait for static access to 'price' property
+ * HasPrice trait for static access to 'price' property.
  */
 public interface HasPrice extends Document {
 

abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/HasType.java

@@ -23,13 +23,12 @@
 
 package com.iluwatar.abstractdocument.domain;
 
-import java.util.Optional;
-
 import com.iluwatar.abstractdocument.Document;
 import com.iluwatar.abstractdocument.domain.enums.Property;
+import java.util.Optional;
 
 /**
- * HasType trait for static access to 'type' property
+ * HasType trait for static access to 'type' property.
  */
 public interface HasType extends Document {
 

abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/Part.java

@@ -23,12 +23,11 @@
 
 package com.iluwatar.abstractdocument.domain;
 
-import java.util.Map;
-
 import com.iluwatar.abstractdocument.AbstractDocument;
+import java.util.Map;
 
 /**
- * Part entity
+ * Part entity.
  */
 public class Part extends AbstractDocument implements HasType, HasModel, HasPrice {
 

abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/enums/Property.java

@@ -24,9 +24,7 @@
 package com.iluwatar.abstractdocument.domain.enums;
 
 /**
- * 
- * Enum To Describe Property type
- *
+ * Enum To Describe Property type.
  */
 public enum Property {
 

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 static org.junit.jupiter.api.Assertions.*;
+import org.junit.jupiter.api.Test;
 
 /**
  * AbstractDocument test class
@@ -61,22 +61,22 @@ public void shouldRetrieveChildren() {
 
     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);
-    DocumentImplementation document = new DocumentImplementation(props);
+    var props = Map.of(KEY, (Object) VALUE);
+    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 static org.junit.jupiter.api.Assertions.assertEquals;
+import org.junit.jupiter.api.Test;
 
 /**
  * Test for Part and Car
@@ -47,27 +46,27 @@ public class DomainTest {
 
   @Test
   public void shouldConstructPart() {
-    Map<String, Object> partProperties = Map.of(
-            Property.TYPE.toString(), TEST_PART_TYPE,
-            Property.MODEL.toString(), TEST_PART_MODEL,
-            Property.PRICE.toString(), TEST_PART_PRICE);
-    Part part = new Part(partProperties);
-
-    assertEquals(TEST_PART_TYPE, part.getType().get());
-    assertEquals(TEST_PART_MODEL, part.getModel().get());
-    assertEquals(TEST_PART_PRICE, part.getPrice().get());
+    var partProperties = Map.of(
+        Property.TYPE.toString(), TEST_PART_TYPE,
+        Property.MODEL.toString(), TEST_PART_MODEL,
+        Property.PRICE.toString(), (Object) TEST_PART_PRICE
+    );
+    var part = new Part(partProperties);
+    assertEquals(TEST_PART_TYPE, part.getType().orElseThrow());
+    assertEquals(TEST_PART_MODEL, part.getModel().orElseThrow());
+    assertEquals(TEST_PART_PRICE, part.getPrice().orElseThrow());
   }
 
   @Test
   public void shouldConstructCar() {
-    Map<String, Object> carProperties = Map.of(
-            Property.MODEL.toString(), TEST_CAR_MODEL,
-            Property.PRICE.toString(), TEST_CAR_PRICE,
-            Property.PARTS.toString(), List.of(Map.of(), Map.of()));
-    Car car = new Car(carProperties);
-
-    assertEquals(TEST_CAR_MODEL, car.getModel().get());
-    assertEquals(TEST_CAR_PRICE, car.getPrice().get());
+    var carProperties = Map.of(
+        Property.MODEL.toString(), TEST_CAR_MODEL,
+        Property.PRICE.toString(), TEST_CAR_PRICE,
+        Property.PARTS.toString(), List.of(Map.of(), Map.of())
+    );
+    var car = new Car(carProperties);
+    assertEquals(TEST_CAR_MODEL, car.getModel().orElseThrow());
+    assertEquals(TEST_CAR_PRICE, car.getPrice().orElseThrow());
     assertEquals(2, car.getParts().count());
   }