Merge remote-tracking branch 'upstream/master'

core-java-8/.project

@@ -1,15 +1,10 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <projectDescription>
-	<name>core-java-8</name>
+	<name>core-java8</name>
 	<comment></comment>
 	<projects>
 	</projects>
 	<buildSpec>
-		<buildCommand>
-			<name>org.eclipse.jdt.core.javabuilder</name>
-			<arguments>
-			</arguments>
-		</buildCommand>
 		<buildCommand>
 			<name>org.eclipse.m2e.core.maven2Builder</name>
 			<arguments>
@@ -17,8 +12,6 @@
 		</buildCommand>
 	</buildSpec>
 	<natures>
-		<nature>org.eclipse.jem.workbench.JavaEMFNature</nature>
-		<nature>org.eclipse.jdt.core.javanature</nature>
 		<nature>org.eclipse.m2e.core.maven2Nature</nature>
 	</natures>
 </projectDescription>

core-java-8/.settings/.jsdtscope

@@ -1,5 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<classpath>
-	<classpathentry kind="src" path="src/main/webapp"/>
-	<classpathentry kind="output" path=""/>
-</classpath>

core-java-8/.settings/org.eclipse.jdt.core.prefs

@@ -1,101 +0,0 @@
-eclipse.preferences.version=1
-org.eclipse.jdt.core.compiler.annotation.inheritNullAnnotations=disabled
-org.eclipse.jdt.core.compiler.annotation.missingNonNullByDefaultAnnotation=ignore
-org.eclipse.jdt.core.compiler.annotation.nonnull=org.eclipse.jdt.annotation.NonNull
-org.eclipse.jdt.core.compiler.annotation.nonnullbydefault=org.eclipse.jdt.annotation.NonNullByDefault
-org.eclipse.jdt.core.compiler.annotation.nullable=org.eclipse.jdt.annotation.Nullable
-org.eclipse.jdt.core.compiler.annotation.nullanalysis=disabled
-org.eclipse.jdt.core.compiler.codegen.inlineJsrBytecode=enabled
-org.eclipse.jdt.core.compiler.codegen.methodParameters=do not generate
-org.eclipse.jdt.core.compiler.codegen.targetPlatform=1.8
-org.eclipse.jdt.core.compiler.codegen.unusedLocal=preserve
-org.eclipse.jdt.core.compiler.compliance=1.8
-org.eclipse.jdt.core.compiler.debug.lineNumber=generate
-org.eclipse.jdt.core.compiler.debug.localVariable=generate
-org.eclipse.jdt.core.compiler.debug.sourceFile=generate
-org.eclipse.jdt.core.compiler.problem.annotationSuperInterface=warning
-org.eclipse.jdt.core.compiler.problem.assertIdentifier=error
-org.eclipse.jdt.core.compiler.problem.autoboxing=ignore
-org.eclipse.jdt.core.compiler.problem.comparingIdentical=warning
-org.eclipse.jdt.core.compiler.problem.deadCode=warning
-org.eclipse.jdt.core.compiler.problem.deprecation=warning
-org.eclipse.jdt.core.compiler.problem.deprecationInDeprecatedCode=disabled
-org.eclipse.jdt.core.compiler.problem.deprecationWhenOverridingDeprecatedMethod=disabled
-org.eclipse.jdt.core.compiler.problem.discouragedReference=warning
-org.eclipse.jdt.core.compiler.problem.emptyStatement=ignore
-org.eclipse.jdt.core.compiler.problem.enumIdentifier=error
-org.eclipse.jdt.core.compiler.problem.explicitlyClosedAutoCloseable=ignore
-org.eclipse.jdt.core.compiler.problem.fallthroughCase=ignore
-org.eclipse.jdt.core.compiler.problem.fatalOptionalError=disabled
-org.eclipse.jdt.core.compiler.problem.fieldHiding=warning
-org.eclipse.jdt.core.compiler.problem.finalParameterBound=warning
-org.eclipse.jdt.core.compiler.problem.finallyBlockNotCompletingNormally=warning
-org.eclipse.jdt.core.compiler.problem.forbiddenReference=warning
-org.eclipse.jdt.core.compiler.problem.hiddenCatchBlock=warning
-org.eclipse.jdt.core.compiler.problem.includeNullInfoFromAsserts=disabled
-org.eclipse.jdt.core.compiler.problem.incompatibleNonInheritedInterfaceMethod=warning
-org.eclipse.jdt.core.compiler.problem.incompleteEnumSwitch=ignore
-org.eclipse.jdt.core.compiler.problem.indirectStaticAccess=ignore
-org.eclipse.jdt.core.compiler.problem.localVariableHiding=warning
-org.eclipse.jdt.core.compiler.problem.methodWithConstructorName=warning
-org.eclipse.jdt.core.compiler.problem.missingDefaultCase=ignore
-org.eclipse.jdt.core.compiler.problem.missingDeprecatedAnnotation=ignore
-org.eclipse.jdt.core.compiler.problem.missingEnumCaseDespiteDefault=disabled
-org.eclipse.jdt.core.compiler.problem.missingHashCodeMethod=ignore
-org.eclipse.jdt.core.compiler.problem.missingOverrideAnnotation=ignore
-org.eclipse.jdt.core.compiler.problem.missingOverrideAnnotationForInterfaceMethodImplementation=enabled
-org.eclipse.jdt.core.compiler.problem.missingSerialVersion=warning
-org.eclipse.jdt.core.compiler.problem.missingSynchronizedOnInheritedMethod=ignore
-org.eclipse.jdt.core.compiler.problem.noEffectAssignment=warning
-org.eclipse.jdt.core.compiler.problem.noImplicitStringConversion=warning
-org.eclipse.jdt.core.compiler.problem.nonExternalizedStringLiteral=ignore
-org.eclipse.jdt.core.compiler.problem.nonnullParameterAnnotationDropped=warning
-org.eclipse.jdt.core.compiler.problem.nullAnnotationInferenceConflict=error
-org.eclipse.jdt.core.compiler.problem.nullReference=warning
-org.eclipse.jdt.core.compiler.problem.nullSpecViolation=error
-org.eclipse.jdt.core.compiler.problem.nullUncheckedConversion=warning
-org.eclipse.jdt.core.compiler.problem.overridingPackageDefaultMethod=warning
-org.eclipse.jdt.core.compiler.problem.parameterAssignment=ignore
-org.eclipse.jdt.core.compiler.problem.possibleAccidentalBooleanAssignment=ignore
-org.eclipse.jdt.core.compiler.problem.potentialNullReference=ignore
-org.eclipse.jdt.core.compiler.problem.potentiallyUnclosedCloseable=ignore
-org.eclipse.jdt.core.compiler.problem.rawTypeReference=warning
-org.eclipse.jdt.core.compiler.problem.redundantNullAnnotation=warning
-org.eclipse.jdt.core.compiler.problem.redundantNullCheck=ignore
-org.eclipse.jdt.core.compiler.problem.redundantSpecificationOfTypeArguments=ignore
-org.eclipse.jdt.core.compiler.problem.redundantSuperinterface=ignore
-org.eclipse.jdt.core.compiler.problem.reportMethodCanBePotentiallyStatic=ignore
-org.eclipse.jdt.core.compiler.problem.reportMethodCanBeStatic=ignore
-org.eclipse.jdt.core.compiler.problem.specialParameterHidingField=disabled
-org.eclipse.jdt.core.compiler.problem.staticAccessReceiver=warning
-org.eclipse.jdt.core.compiler.problem.suppressOptionalErrors=disabled
-org.eclipse.jdt.core.compiler.problem.suppressWarnings=enabled
-org.eclipse.jdt.core.compiler.problem.syntacticNullAnalysisForFields=disabled
-org.eclipse.jdt.core.compiler.problem.syntheticAccessEmulation=ignore
-org.eclipse.jdt.core.compiler.problem.typeParameterHiding=error
-org.eclipse.jdt.core.compiler.problem.unavoidableGenericTypeProblems=enabled
-org.eclipse.jdt.core.compiler.problem.uncheckedTypeOperation=warning
-org.eclipse.jdt.core.compiler.problem.unclosedCloseable=warning
-org.eclipse.jdt.core.compiler.problem.undocumentedEmptyBlock=ignore
-org.eclipse.jdt.core.compiler.problem.unhandledWarningToken=warning
-org.eclipse.jdt.core.compiler.problem.unnecessaryElse=ignore
-org.eclipse.jdt.core.compiler.problem.unnecessaryTypeCheck=ignore
-org.eclipse.jdt.core.compiler.problem.unqualifiedFieldAccess=ignore
-org.eclipse.jdt.core.compiler.problem.unusedDeclaredThrownException=ignore
-org.eclipse.jdt.core.compiler.problem.unusedDeclaredThrownExceptionExemptExceptionAndThrowable=enabled
-org.eclipse.jdt.core.compiler.problem.unusedDeclaredThrownExceptionIncludeDocCommentReference=enabled
-org.eclipse.jdt.core.compiler.problem.unusedDeclaredThrownExceptionWhenOverriding=disabled
-org.eclipse.jdt.core.compiler.problem.unusedExceptionParameter=ignore
-org.eclipse.jdt.core.compiler.problem.unusedImport=warning
-org.eclipse.jdt.core.compiler.problem.unusedLabel=warning
-org.eclipse.jdt.core.compiler.problem.unusedLocal=warning
-org.eclipse.jdt.core.compiler.problem.unusedObjectAllocation=ignore
-org.eclipse.jdt.core.compiler.problem.unusedParameter=ignore
-org.eclipse.jdt.core.compiler.problem.unusedParameterIncludeDocCommentReference=enabled
-org.eclipse.jdt.core.compiler.problem.unusedParameterWhenImplementingAbstract=disabled
-org.eclipse.jdt.core.compiler.problem.unusedParameterWhenOverridingConcrete=disabled
-org.eclipse.jdt.core.compiler.problem.unusedPrivateMember=warning
-org.eclipse.jdt.core.compiler.problem.unusedTypeParameter=ignore
-org.eclipse.jdt.core.compiler.problem.unusedWarningToken=warning
-org.eclipse.jdt.core.compiler.problem.varargsArgumentNeedCast=warning
-org.eclipse.jdt.core.compiler.source=1.8

core-java-8/.settings/org.eclipse.jdt.ui.prefs

@@ -1,57 +0,0 @@
-eclipse.preferences.version=1
-editor_save_participant_org.eclipse.jdt.ui.postsavelistener.cleanup=true
-sp_cleanup.add_default_serial_version_id=true
-sp_cleanup.add_generated_serial_version_id=false
-sp_cleanup.add_missing_annotations=true
-sp_cleanup.add_missing_deprecated_annotations=true
-sp_cleanup.add_missing_methods=false
-sp_cleanup.add_missing_nls_tags=false
-sp_cleanup.add_missing_override_annotations=true
-sp_cleanup.add_missing_override_annotations_interface_methods=true
-sp_cleanup.add_serial_version_id=false
-sp_cleanup.always_use_blocks=true
-sp_cleanup.always_use_parentheses_in_expressions=true
-sp_cleanup.always_use_this_for_non_static_field_access=false
-sp_cleanup.always_use_this_for_non_static_method_access=false
-sp_cleanup.convert_functional_interfaces=false
-sp_cleanup.convert_to_enhanced_for_loop=true
-sp_cleanup.correct_indentation=true
-sp_cleanup.format_source_code=true
-sp_cleanup.format_source_code_changes_only=true
-sp_cleanup.make_local_variable_final=true
-sp_cleanup.make_parameters_final=true
-sp_cleanup.make_private_fields_final=false
-sp_cleanup.make_type_abstract_if_missing_method=false
-sp_cleanup.make_variable_declarations_final=true
-sp_cleanup.never_use_blocks=false
-sp_cleanup.never_use_parentheses_in_expressions=false
-sp_cleanup.on_save_use_additional_actions=true
-sp_cleanup.organize_imports=true
-sp_cleanup.qualify_static_field_accesses_with_declaring_class=false
-sp_cleanup.qualify_static_member_accesses_through_instances_with_declaring_class=true
-sp_cleanup.qualify_static_member_accesses_through_subtypes_with_declaring_class=true
-sp_cleanup.qualify_static_member_accesses_with_declaring_class=true
-sp_cleanup.qualify_static_method_accesses_with_declaring_class=false
-sp_cleanup.remove_private_constructors=true
-sp_cleanup.remove_trailing_whitespaces=true
-sp_cleanup.remove_trailing_whitespaces_all=true
-sp_cleanup.remove_trailing_whitespaces_ignore_empty=false
-sp_cleanup.remove_unnecessary_casts=true
-sp_cleanup.remove_unnecessary_nls_tags=false
-sp_cleanup.remove_unused_imports=true
-sp_cleanup.remove_unused_local_variables=false
-sp_cleanup.remove_unused_private_fields=true
-sp_cleanup.remove_unused_private_members=false
-sp_cleanup.remove_unused_private_methods=true
-sp_cleanup.remove_unused_private_types=true
-sp_cleanup.sort_members=false
-sp_cleanup.sort_members_all=false
-sp_cleanup.use_anonymous_class_creation=false
-sp_cleanup.use_blocks=true
-sp_cleanup.use_blocks_only_for_return_and_throw=false
-sp_cleanup.use_lambda=false
-sp_cleanup.use_parentheses_in_expressions=false
-sp_cleanup.use_this_for_non_static_field_access=true
-sp_cleanup.use_this_for_non_static_field_access_only_if_necessary=true
-sp_cleanup.use_this_for_non_static_method_access=true
-sp_cleanup.use_this_for_non_static_method_access_only_if_necessary=true

core-java-8/.settings/org.eclipse.m2e.core.prefs

@@ -1,4 +0,0 @@
-activeProfiles=
-eclipse.preferences.version=1
-resolveWorkspaceProjects=true
-version=1

core-java-8/.springBeans

@@ -1,14 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<beansProjectDescription>
-	<version>1</version>
-	<pluginVersion><![CDATA[3.3.0.201307091516-RELEASE]]></pluginVersion>
-	<configSuffixes>
-		<configSuffix><![CDATA[xml]]></configSuffix>
-	</configSuffixes>
-	<enableImports><![CDATA[false]]></enableImports>
-	<configs>
-		<config>src/main/webapp/WEB-INF/api-servlet.xml</config>
-	</configs>
-	<configSets>
-	</configSets>
-</beansProjectDescription>

core-java-8/pom.xml

@@ -1,4 +1,5 @@
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.baeldung</groupId>
     <artifactId>core-java8</artifactId>

core-java-8/src/main/java/com/baeldung/enums/Pizza.java

@@ -0,0 +1,91 @@
+package com.baeldung.enums;
+
+import java.util.EnumMap;
+import java.util.EnumSet;
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class Pizza {
+
+    private static EnumSet<PizzaStatusEnum> deliveredPizzaStatuses =
+            EnumSet.of(PizzaStatusEnum.DELIVERED);
+
+    private PizzaStatusEnum status;
+
+    public enum PizzaStatusEnum {
+        ORDERED(5) {
+            @Override
+            public boolean isOrdered() {
+                return true;
+            }
+        },
+        READY(2) {
+            @Override
+            public boolean isReady() {
+                return true;
+            }
+        },
+        DELIVERED(0) {
+            @Override
+            public boolean isDelivered() {
+                return true;
+            }
+        };
+
+        private int timeToDelivery;
+
+        public boolean isOrdered() {
+            return false;
+        }
+
+        public boolean isReady() {
+            return false;
+        }
+
+        public boolean isDelivered() {
+            return false;
+        }
+
+        public int getTimeToDelivery() {
+            return timeToDelivery;
+        }
+
+        PizzaStatusEnum(int timeToDelivery) {
+            this.timeToDelivery = timeToDelivery;
+        }
+    }
+
+    public PizzaStatusEnum getStatus() {
+        return status;
+    }
+
+    public void setStatus(PizzaStatusEnum status) {
+        this.status = status;
+    }
+
+    public boolean isDeliverable() {
+        return this.status.isReady();
+    }
+
+    public void printTimeToDeliver() {
+        System.out.println("Time to delivery is " + this.getStatus().getTimeToDelivery() + " days");
+    }
+
+    public static List<Pizza> getAllUndeliveredPizzas(List<Pizza> input) {
+        return input.stream().filter((s) -> !deliveredPizzaStatuses.contains(s.getStatus())).collect(Collectors.toList());
+    }
+
+    public static EnumMap<PizzaStatusEnum, List<Pizza>> groupPizzaByStatus(List<Pizza> pzList) {
+        return pzList.stream().collect(
+                Collectors.groupingBy(Pizza::getStatus,
+                        () -> new EnumMap<>(PizzaStatusEnum.class), Collectors.toList()));
+    }
+
+    public void deliver() {
+        if (isDeliverable()) {
+            PizzaDeliverySystemConfiguration.getInstance().getDeliveryStrategy().deliver(this);
+            this.setStatus(PizzaStatusEnum.DELIVERED);
+        }
+    }
+
+}

core-java-8/src/main/java/com/baeldung/enums/PizzaDeliveryStrategy.java

@@ -0,0 +1,18 @@
+package com.baeldung.enums;
+
+public enum PizzaDeliveryStrategy {
+    EXPRESS {
+        @Override
+        public void deliver(Pizza pz) {
+            System.out.println("Pizza will be delivered in express mode");
+        }
+    },
+    NORMAL {
+        @Override
+        public void deliver(Pizza pz) {
+            System.out.println("Pizza will be delivered in normal mode");
+        }
+    };
+
+    public abstract void deliver(Pizza pz);
+}

core-java-8/src/main/java/com/baeldung/enums/PizzaDeliverySystemConfiguration.java

@@ -0,0 +1,22 @@
+package com.baeldung.enums;
+
+
+public enum PizzaDeliverySystemConfiguration {
+    INSTANCE;
+
+    PizzaDeliverySystemConfiguration() {
+        // Do the configuration initialization which
+        // involves overriding defaults like delivery strategy
+    }
+
+    private PizzaDeliveryStrategy deliveryStrategy = PizzaDeliveryStrategy.NORMAL;
+
+    public static PizzaDeliverySystemConfiguration getInstance() {
+        return INSTANCE;
+    }
+
+    public PizzaDeliveryStrategy getDeliveryStrategy() {
+        return deliveryStrategy;
+    }
+
+}

core-java-8/src/main/java/com/baeldung/forkjoin/CustomRecursiveAction.java

@@ -0,0 +1,49 @@
+package com.baeldung.forkjoin;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+import java.util.concurrent.ForkJoinTask;
+import java.util.concurrent.RecursiveAction;
+import java.util.logging.Logger;
+
+public class CustomRecursiveAction extends RecursiveAction {
+
+    private String workLoad = "";
+    private static final int THRESHOLD = 4;
+
+    private static Logger logger = Logger.getAnonymousLogger();
+
+    public CustomRecursiveAction(String workLoad) {
+        this.workLoad = workLoad;
+    }
+
+    @Override
+    protected void compute() {
+
+        if (workLoad.length() > THRESHOLD) {
+            ForkJoinTask.invokeAll(createSubtasks());
+        } else {
+            processing(workLoad);
+        }
+    }
+
+    private Collection<CustomRecursiveAction> createSubtasks() {
+
+        List<CustomRecursiveAction> subtasks =
+                new ArrayList<>();
+
+        String partOne = workLoad.substring(0, workLoad.length() / 2);
+        String partTwo = workLoad.substring(workLoad.length() / 2, workLoad.length());
+
+        subtasks.add(new CustomRecursiveAction(partOne));
+        subtasks.add(new CustomRecursiveAction(partTwo));
+
+        return subtasks;
+    }
+
+    private void processing(String work) {
+        String result = work.toUpperCase();
+        logger.info("This result - (" + result + ") - was processed by " + Thread.currentThread().getName());
+    }
+}

core-java-8/src/main/java/com/baeldung/forkjoin/CustomRecursiveTask.java

@@ -0,0 +1,51 @@
+package com.baeldung.forkjoin;
+
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.List;
+import java.util.concurrent.ForkJoinTask;
+import java.util.concurrent.RecursiveTask;
+
+public class CustomRecursiveTask extends RecursiveTask<Integer> {
+
+    private int[] arr;
+
+    private static final int THRESHOLD = 20;
+
+    public CustomRecursiveTask(int[] arr) {
+        this.arr = arr;
+    }
+
+    @Override
+    protected Integer compute() {
+
+        if (arr.length > THRESHOLD) {
+
+            return ForkJoinTask.invokeAll(createSubtasks())
+                    .stream()
+                    .mapToInt(ForkJoinTask::join)
+                    .sum();
+
+        } else {
+            return processing(arr);
+        }
+    }
+
+    private Collection<CustomRecursiveTask> createSubtasks() {
+        List<CustomRecursiveTask> dividedTasks = new ArrayList<>();
+        dividedTasks.add(new CustomRecursiveTask(
+                Arrays.copyOfRange(arr, 0, arr.length / 2)));
+        dividedTasks.add(new CustomRecursiveTask(
+                Arrays.copyOfRange(arr, arr.length / 2, arr.length)));
+        return dividedTasks;
+    }
+
+    private Integer processing(int[] arr) {
+        return Arrays.stream(arr)
+                .filter(a -> a > 10 && a < 27)
+                .map(a -> a * 10)
+                .sum();
+    }
+}

core-java-8/src/main/java/com/baeldung/forkjoin/util/PoolUtil.java

@@ -0,0 +1,10 @@
+package com.baeldung.forkjoin.util;
+
+
+import java.util.concurrent.ForkJoinPool;
+
+public class PoolUtil {
+
+    public static ForkJoinPool forkJoinPool = new ForkJoinPool(2);
+
+}

core-java-8/src/main/java/com/baeldung/java_8_features/Address.java

@@ -0,0 +1,14 @@
+package com.baeldung.java_8_features;
+
+public class Address {
+
+    private String street;
+
+    public String getStreet() {
+        return street;
+    }
+
+    public void setStreet(String street) {
+        this.street = street;
+    }
+}

core-java-8/src/main/java/com/baeldung/java_8_features/CustomException.java

@@ -0,0 +1,4 @@
+package com.baeldung.java_8_features;
+
+public class CustomException extends RuntimeException {
+}

core-java-8/src/main/java/com/baeldung/java_8_features/Detail.java

@@ -0,0 +1,13 @@
+package com.baeldung.java_8_features;
+
+import java.util.Arrays;
+import java.util.List;
+
+public class Detail {
+
+    private static final List<String> PARTS = Arrays.asList("turbine", "pump");
+
+    public List<String> getParts() {
+        return PARTS;
+    }
+}

core-java-8/src/main/java/com/baeldung/java_8_features/OptionalAddress.java

@@ -0,0 +1,16 @@
+package com.baeldung.java_8_features;
+
+import java.util.Optional;
+
+public class OptionalAddress {
+
+    private String street;
+
+    public Optional<String> getStreet() {
+        return Optional.ofNullable(street);
+    }
+
+    public void setStreet(String street) {
+        this.street = street;
+    }
+}

core-java-8/src/main/java/com/baeldung/java_8_features/OptionalUser.java

@@ -0,0 +1,16 @@
+package com.baeldung.java_8_features;
+
+import java.util.Optional;
+
+public class OptionalUser {
+
+    private OptionalAddress address;
+
+    public Optional<OptionalAddress> getAddress() {
+        return Optional.of(address);
+    }
+
+    public void setAddress(OptionalAddress address) {
+        this.address = address;
+    }
+}

core-java-8/src/main/java/com/baeldung/java_8_features/User.java

@@ -0,0 +1,40 @@
+package com.baeldung.java_8_features;
+
+import java.util.Optional;
+
+public class User {
+
+    private String name;
+
+    private Address address;
+
+    public Address getAddress() {
+        return address;
+    }
+
+    public void setAddress(Address address) {
+        this.address = address;
+    }
+
+    public User() {
+    }
+
+    public User(String name) {
+        this.name = name;
+    }
+
+    public static boolean isRealUser(User user) {
+        return true;
+    }
+
+    public String getOrThrow() {
+        String value = null;
+        Optional<String> valueOpt = Optional.ofNullable(value);
+        String result = valueOpt.orElseThrow(CustomException::new).toUpperCase();
+        return result;
+    }
+
+    public boolean isLegalName(String name) {
+        return name.length() > 3 && name.length() < 16;
+    }
+}

core-java-8/src/main/java/com/baeldung/java_8_features/Vehicle.java

@@ -0,0 +1,18 @@
+package com.baeldung.java_8_features;
+
+public interface Vehicle {
+
+    void moveTo(long altitude, long longitude);
+
+    static String producer() {
+        return "N&F Vehicles";
+    }
+
+    default long[] startPosition() {
+        return new long[]{23, 15};
+    }
+
+    default String getOverview() {
+        return "ATV made by " + producer();
+    }
+}

core-java-8/src/main/java/com/baeldung/java_8_features/VehicleImpl.java

@@ -0,0 +1,9 @@
+package com.baeldung.java_8_features;
+
+public class VehicleImpl implements  Vehicle {
+
+    @Override
+    public void moveTo(long altitude, long longitude) {
+        //do nothing
+    }
+}

core-java-8/src/main/java/com/baeldung/unzip/UnzipFile.java

@@ -13,7 +13,7 @@ public class UnzipFile {
         final byte[] buffer = new byte[1024];
         final ZipInputStream zis = new ZipInputStream(new FileInputStream(fileZip));
         ZipEntry zipEntry = zis.getNextEntry();
-        while(zipEntry != null){
+        while (zipEntry != null) {
             final String fileName = zipEntry.getName();
             final File newFile = new File("src/main/resources/unzipTest/" + fileName);
             final FileOutputStream fos = new FileOutputStream(newFile);

core-java-8/src/main/java/com/baeldung/zip/ZipFile.java

@@ -18,7 +18,7 @@ public class ZipFile {
         zipOut.putNextEntry(zipEntry);
         final byte[] bytes = new byte[1024];
         int length;
-        while((length = fis.read(bytes)) >= 0) {
+        while ((length = fis.read(bytes)) >= 0) {
             zipOut.write(bytes, 0, length);
         }
         zipOut.close();

core-java-8/src/main/java/com/baeldung/zip/ZipMultipleFiles.java

@@ -22,7 +22,7 @@ public class ZipMultipleFiles {
 
             final byte[] bytes = new byte[1024];
             int length;
-            while((length = fis.read(bytes)) >= 0) {
+            while ((length = fis.read(bytes)) >= 0) {
                 zipOut.write(bytes, 0, length);
             }
             fis.close();

core-java-8/src/main/resources/logback.xml

@@ -10,7 +10,7 @@
     <!-- <logger name="org.springframework" level="WARN" /> -->
 
     <root level="INFO">
-        <appender-ref ref="STDOUT" />
+        <appender-ref ref="STDOUT"/>
     </root>
 
 </configuration>

core-java-8/src/test/java/com/baeldung/doublecolon/TestComputerUtils.java

@@ -6,7 +6,9 @@ import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
 
-import java.util.*;
+import java.util.Arrays;
+import java.util.Comparator;
+import java.util.List;
 import java.util.function.BiFunction;
 
 import static com.baeldung.doublecolon.ComputerUtils.*;

core-java-8/src/test/java/com/baeldung/enums/PizzaTest.java

@@ -0,0 +1,80 @@
+package com.baeldung.enums;
+
+
+import org.junit.Test;
+
+import java.util.ArrayList;
+import java.util.EnumMap;
+import java.util.List;
+
+import static junit.framework.TestCase.assertTrue;
+
+public class PizzaTest {
+
+    @Test
+    public void givenPizaOrder_whenReady_thenDeliverable() {
+        Pizza testPz = new Pizza();
+        testPz.setStatus(Pizza.PizzaStatusEnum.READY);
+        assertTrue(testPz.isDeliverable());
+    }
+
+    @Test
+    public void givenPizaOrders_whenRetrievingUnDeliveredPzs_thenCorrectlyRetrieved() {
+        List<Pizza> pzList = new ArrayList<>();
+        Pizza pz1 = new Pizza();
+        pz1.setStatus(Pizza.PizzaStatusEnum.DELIVERED);
+
+        Pizza pz2 = new Pizza();
+        pz2.setStatus(Pizza.PizzaStatusEnum.ORDERED);
+
+        Pizza pz3 = new Pizza();
+        pz3.setStatus(Pizza.PizzaStatusEnum.ORDERED);
+
+        Pizza pz4 = new Pizza();
+        pz4.setStatus(Pizza.PizzaStatusEnum.READY);
+
+        pzList.add(pz1);
+        pzList.add(pz2);
+        pzList.add(pz3);
+        pzList.add(pz4);
+
+        List<Pizza> undeliveredPzs = Pizza.getAllUndeliveredPizzas(pzList);
+        assertTrue(undeliveredPzs.size() == 3);
+    }
+
+    @Test
+    public void givenPizaOrders_whenGroupByStatusCalled_thenCorrectlyGrouped() {
+
+        List<Pizza> pzList = new ArrayList<>();
+        Pizza pz1 = new Pizza();
+        pz1.setStatus(Pizza.PizzaStatusEnum.DELIVERED);
+
+        Pizza pz2 = new Pizza();
+        pz2.setStatus(Pizza.PizzaStatusEnum.ORDERED);
+
+        Pizza pz3 = new Pizza();
+        pz3.setStatus(Pizza.PizzaStatusEnum.ORDERED);
+
+        Pizza pz4 = new Pizza();
+        pz4.setStatus(Pizza.PizzaStatusEnum.READY);
+
+        pzList.add(pz1);
+        pzList.add(pz2);
+        pzList.add(pz3);
+        pzList.add(pz4);
+
+        EnumMap<Pizza.PizzaStatusEnum, List<Pizza>> map = Pizza.groupPizzaByStatus(pzList);
+        assertTrue(map.get(Pizza.PizzaStatusEnum.DELIVERED).size() == 1);
+        assertTrue(map.get(Pizza.PizzaStatusEnum.ORDERED).size() == 2);
+        assertTrue(map.get(Pizza.PizzaStatusEnum.READY).size() == 1);
+    }
+
+    @Test
+    public void givenPizaOrder_whenDelivered_thenPizzaGetsDeliveredAndStatusChanges() {
+        Pizza pz = new Pizza();
+        pz.setStatus(Pizza.PizzaStatusEnum.READY);
+        pz.deliver();
+        assertTrue(pz.getStatus() == Pizza.PizzaStatusEnum.DELIVERED);
+    }
+
+}

core-java-8/src/test/java/com/baeldung/java8/Java8CollectionCleanupUnitTest.java

@@ -1,14 +1,13 @@
 package com.baeldung.java8;
 
-import static org.hamcrest.Matchers.hasSize;
-import static org.junit.Assert.assertThat;
+import com.google.common.collect.Lists;
+import org.junit.Test;
 
 import java.util.List;
 import java.util.stream.Collectors;
 
-import org.junit.Test;
-
-import com.google.common.collect.Lists;
+import static org.hamcrest.Matchers.hasSize;
+import static org.junit.Assert.assertThat;
 
 public class Java8CollectionCleanupUnitTest {
 

core-java-8/src/test/java/com/baeldung/java8/Java8DefaultStaticIntefaceMethodsTest.java

@@ -0,0 +1,27 @@
+package com.baeldung.java8;
+
+import com.baeldung.java_8_features.Vehicle;
+import com.baeldung.java_8_features.VehicleImpl;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class Java8DefaultStaticIntefaceMethodsTest {
+
+    @Test
+    public void callStaticInterfaceMethdosMethods_whenExpectedResults_thenCorrect() {
+        Vehicle vehicle = new VehicleImpl();
+        String overview = vehicle.getOverview();
+        long[] startPosition = vehicle.startPosition();
+
+        assertEquals(overview, "ATV made by N&F Vehicles");
+        assertEquals(startPosition[0], 23);
+        assertEquals(startPosition[1], 15);
+    }
+
+    @Test
+    public void callDefaultInterfaceMethods_whenExpectedResults_thenCorrect() {
+        String producer = Vehicle.producer();
+        assertEquals(producer, "N&F Vehicles");
+    }
+}

core-java-8/src/test/java/com/baeldung/java8/Java8ExecutorServiceTest.java

@@ -7,6 +7,7 @@ import org.junit.Test;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.*;
+
 import static org.junit.Assert.*;
 
 
@@ -53,8 +54,8 @@ public class Java8ExecutorServiceTest {
     public void creationSubmittingTasksShuttingDownNow_whenShutDownAfterAwating_thenCorrect() {
 
         ExecutorService threadPoolExecutor =
-          new ThreadPoolExecutor(1, 1, 0L, TimeUnit.MILLISECONDS,
-            new LinkedBlockingQueue<>());
+                new ThreadPoolExecutor(1, 1, 0L, TimeUnit.MILLISECONDS,
+                        new LinkedBlockingQueue<>());
 
         for (int i = 0; i < 100; i++) {
             threadPoolExecutor.submit(callableTask);