Merge remote-tracking branch 'upstream/master'

README.md

@@ -2,7 +2,7 @@
 The "REST with Spring" Classes
 ==============================
 
-After 5 months of work, here's the Master Class of REST With Spring: <br/>
+Here's the Master Class of REST With Spring (price changes permanently next Friday): <br/>
 **[>> THE REST WITH SPRING MASTER CLASS](http://www.baeldung.com/rest-with-spring-course?utm_source=github&utm_medium=social&utm_content=tutorials&utm_campaign=rws#master-class)**
 
 And here's the Master Class of Learn Spring Security: <br/>

algorithms/src/main/java/com/baeldung/algorithms/mcts/montecarlo/State.java

@@ -87,7 +87,7 @@ public class State {
     void randomPlay() {
         List<Position> availablePositions = this.board.getEmptyPositions();
         int totalPossibilities = availablePositions.size();
-        int selectRandom = (int) (Math.random() * ((totalPossibilities - 1) + 1));
+        int selectRandom = (int) (Math.random() * totalPossibilities);
         this.board.performMove(this.playerNo, availablePositions.get(selectRandom));
     }
 

algorithms/src/main/java/com/baeldung/algorithms/mcts/tree/Node.java

@@ -65,7 +65,7 @@ public class Node {
 
     public Node getRandomChildNode() {
         int noOfPossibleMoves = this.childArray.size();
-        int selectRandom = (int) (Math.random() * ((noOfPossibleMoves - 1) + 1));
+        int selectRandom = (int) (Math.random() * noOfPossibleMoves);
         return this.childArray.get(selectRandom);
     }
 

algorithms/src/main/java/com/baeldung/algorithms/string/EnglishAlphabetLetters.java

@@ -0,0 +1,35 @@
+package com.baeldung.algorithms.string;
+
+public class EnglishAlphabetLetters {
+
+    public static boolean checkStringForAllTheLetters(String input) {
+        boolean[] visited = new boolean[26];
+
+        int index = 0;
+
+        for (int id = 0; id < input.length(); id++) {
+            if ('a' <= input.charAt(id) && input.charAt(id) <= 'z') {
+                index = input.charAt(id) - 'a';
+            } else if ('A' <= input.charAt(id) && input.charAt(id) <= 'Z') {
+                index = input.charAt(id) - 'A';
+            }
+            visited[index] = true;
+        }
+
+        for (int id = 0; id < 26; id++) {
+            if (!visited[id]) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    public static boolean checkStringForAllLetterUsingStream(String input) {
+        long c = input.toLowerCase().chars().filter(ch -> ch >= 'a' && ch <= 'z').distinct().count();
+        return c == 26;
+    }
+
+    public static void main(String[] args) {
+        checkStringForAllLetterUsingStream("intit");
+    }
+}

algorithms/src/test/java/com/baeldung/algorithms/AntColonyOptimizationLongRunningUnitTest.java

@@ -1,4 +1,4 @@
-package algorithms;
+package com.baeldung.algorithms;
 
 import org.junit.Assert;
 import org.junit.Test;

algorithms/src/test/java/com/baeldung/algorithms/BinaryGeneticAlgorithmLongRunningUnitTest.java

@@ -1,4 +1,4 @@
-package algorithms;
+package com.baeldung.algorithms;
 
 import org.junit.Assert;
 import org.junit.Test;

algorithms/src/test/java/com/baeldung/algorithms/DijkstraAlgorithmLongRunningUnitTest.java

@@ -1,4 +1,4 @@
-package algorithms;
+package com.baeldung.algorithms;
 
 import org.junit.Test;
 

algorithms/src/test/java/com/baeldung/algorithms/HillClimbingAlgorithmUnitTest.java

@@ -1,4 +1,4 @@
-package algorithms;
+package com.baeldung.algorithms;
 
 import com.baeldung.algorithms.hillclimbing.HillClimbing;
 import com.baeldung.algorithms.hillclimbing.State;

algorithms/src/test/java/com/baeldung/algorithms/MiddleElementLookupUnitTest.java

@@ -1,4 +1,4 @@
-package algorithms;
+package com.baeldung.algorithms;
 
 import com.baeldung.algorithms.middleelementlookup.MiddleElementLookup;
 import com.baeldung.algorithms.middleelementlookup.Node;

algorithms/src/test/java/com/baeldung/algorithms/RtFiniteStateMachineLongRunningUnitTest.java

@@ -1,4 +1,4 @@
-package algorithms;
+package com.baeldung.algorithms;
 
 import com.baeldung.algorithms.automata.*;
 import org.junit.Test;

algorithms/src/test/java/com/baeldung/algorithms/SimulatedAnnealingLongRunningUnitTest.java

@@ -1,4 +1,4 @@
-package algorithms;
+package com.baeldung.algorithms;
 
 import org.junit.Assert;
 import org.junit.Test;

algorithms/src/test/java/com/baeldung/algorithms/StringSearchAlgorithmsUnitTest.java

@@ -1,4 +1,4 @@
-package algorithms;
+package com.baeldung.algorithms;
 
 
 import org.junit.Assert;

algorithms/src/test/java/com/baeldung/algorithms/binarysearch/BinarySearchUnitTest.java

@@ -1,4 +1,4 @@
-package algorithms.binarysearch;
+package com.baeldung.algorithms.binarysearch;
 
 import java.util.Arrays;
 import java.util.List;

algorithms/src/test/java/com/baeldung/algorithms/mcts/MCTSUnitTest.java

@@ -1,4 +1,4 @@
-package algorithms.mcts;
+package com.baeldung.algorithms.mcts;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;

algorithms/src/test/java/com/baeldung/algorithms/minimax/MinimaxUnitTest.java

@@ -1,4 +1,4 @@
-package algorithms.minimax;
+package com.baeldung.algorithms.minimax;
 
 import org.junit.Before;
 import org.junit.Test;

algorithms/src/test/java/com/baeldung/algorithms/string/EnglishAlphabetLettersUnitTest.java

@@ -0,0 +1,20 @@
+package com.baeldung.algorithms.string;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+public class EnglishAlphabetLettersUnitTest {
+
+    @Test
+    void givenString_whenContainsAllCharacter_thenTrue() {
+        String input = "Farmer jack realized that big yellow quilts were expensive";
+        Assertions.assertTrue(EnglishAlphabetLetters.checkStringForAllTheLetters(input));
+    }
+
+    @Test
+    void givenString_whenContainsAllCharacter_thenUsingStreamExpectTrue() {
+        String input = "Farmer jack realized that big yellow quilts were expensive";
+        Assertions.assertTrue(EnglishAlphabetLetters.checkStringForAllLetterUsingStream(input));
+    }
+
+}

apache-avro/src/main/java/com/baeldung/avro/util/serealization/AvroDeSerealizer.java

@@ -5,29 +5,37 @@ import org.apache.avro.io.DatumReader;
 import org.apache.avro.io.Decoder;
 import org.apache.avro.io.DecoderFactory;
 import org.apache.avro.specific.SpecificDatumReader;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import java.io.IOException;
 
 public class AvroDeSerealizer {
 
+    private static Logger logger = LoggerFactory.getLogger(AvroDeSerealizer.class);
+
     public AvroHttpRequest deSerealizeAvroHttpRequestJSON(byte[] data) {
         DatumReader<AvroHttpRequest> reader = new SpecificDatumReader<>(AvroHttpRequest.class);
         Decoder decoder = null;
         try {
-        decoder = DecoderFactory.get().jsonDecoder(AvroHttpRequest.getClassSchema(), new String(data));
+            decoder = DecoderFactory.get()
+                .jsonDecoder(AvroHttpRequest.getClassSchema(), new String(data));
             return reader.read(null, decoder);
         } catch (IOException e) {
-        return null;
+            logger.error("Deserialization error" + e.getMessage());
         }
+        return null;
     }
 
     public AvroHttpRequest deSerealizeAvroHttpRequestBinary(byte[] data) {
         DatumReader<AvroHttpRequest> employeeReader = new SpecificDatumReader<>(AvroHttpRequest.class);
-    Decoder decoder = DecoderFactory.get().binaryDecoder(data, null);
+        Decoder decoder = DecoderFactory.get()
+            .binaryDecoder(data, null);
         try {
             return employeeReader.read(null, decoder);
         } catch (IOException e) {
+            logger.error("Deserialization error" + e.getMessage());
+        }
         return null;
     }
 }
-}

apache-avro/src/main/java/com/baeldung/avro/util/serealization/AvroSerealizer.java

@@ -3,24 +3,29 @@ package com.baeldung.avro.util.serealization;
 import com.baeldung.avro.util.model.AvroHttpRequest;
 import org.apache.avro.io.*;
 import org.apache.avro.specific.SpecificDatumWriter;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 
 public class AvroSerealizer {
 
+    private static final Logger logger = LoggerFactory.getLogger(AvroSerealizer.class);
+
     public byte[] serealizeAvroHttpRequestJSON(AvroHttpRequest request) {
         DatumWriter<AvroHttpRequest> writer = new SpecificDatumWriter<>(AvroHttpRequest.class);
         byte[] data = new byte[0];
         ByteArrayOutputStream stream = new ByteArrayOutputStream();
         Encoder jsonEncoder = null;
         try {
-        jsonEncoder = EncoderFactory.get().jsonEncoder(AvroHttpRequest.getClassSchema(), stream);
+            jsonEncoder = EncoderFactory.get()
+                .jsonEncoder(AvroHttpRequest.getClassSchema(), stream);
             writer.write(request, jsonEncoder);
             jsonEncoder.flush();
             data = stream.toByteArray();
         } catch (IOException e) {
-        data =null;
+            logger.error("Serialization error " + e.getMessage());
         }
         return data;
     }
@@ -29,13 +34,14 @@ public byte[] serealizeAvroHttpRequestBinary(AvroHttpRequest request){
         DatumWriter<AvroHttpRequest> writer = new SpecificDatumWriter<>(AvroHttpRequest.class);
         byte[] data = new byte[0];
         ByteArrayOutputStream stream = new ByteArrayOutputStream();
-    Encoder jsonEncoder = EncoderFactory.get().binaryEncoder(stream,null);
+        Encoder jsonEncoder = EncoderFactory.get()
+            .binaryEncoder(stream, null);
         try {
             writer.write(request, jsonEncoder);
             jsonEncoder.flush();
             data = stream.toByteArray();
         } catch (IOException e) {
-        data = null;
+            logger.error("Serialization error " + e.getMessage());
         }
 
         return data;

apache-avro/src/test/java/com/baeldung/avro/util/serealization/AvroSerealizerDeSerealizerTest.java

@@ -24,8 +24,10 @@ public class AvroSerealizerDeSerealizerTest {
         serealizer = new AvroSerealizer();
         deSerealizer = new AvroDeSerealizer();
 
-        ClientIdentifier clientIdentifier = ClientIdentifier.newBuilder().
+        ClientIdentifier clientIdentifier = ClientIdentifier.newBuilder()
-                setHostName("localhost").setIpAddress("255.255.255.0").build();
+            .setHostName("localhost")
+            .setIpAddress("255.255.255.0")
+            .build();
 
         List<CharSequence> employees = new ArrayList();
         employees.add("James");
@@ -33,9 +35,12 @@ public class AvroSerealizerDeSerealizerTest {
         employees.add("David");
         employees.add("Han");
 
-        request = AvroHttpRequest.newBuilder().setRequestTime(01l)
+        request = AvroHttpRequest.newBuilder()
-                .setActive(Active.YES).setClientIdentifier(clientIdentifier)
+            .setRequestTime(01l)
-                .setEmployeeNames(employees).build();
+            .setActive(Active.YES)
+            .setClientIdentifier(clientIdentifier)
+            .setEmployeeNames(employees)
+            .build();
     }
 
     @After
@@ -43,33 +48,36 @@ public class AvroSerealizerDeSerealizerTest {
     }
 
     @Test
-public void WhenSerialized_UsingJSONEncoder_ObjectGetsSerialized(){
+    public void WhenSerializedUsingJSONEncoder_thenObjectGetsSerialized() {
         byte[] data = serealizer.serealizeAvroHttpRequestJSON(request);
         assertTrue(Objects.nonNull(data));
         assertTrue(data.length > 0);
     }
 
     @Test
-public void WhenSerialized_UsingBinaryEncoder_ObjectGetsSerialized(){
+    public void WhenSerializedUsingBinaryEncoder_thenObjectGetsSerialized() {
         byte[] data = serealizer.serealizeAvroHttpRequestBinary(request);
         assertTrue(Objects.nonNull(data));
         assertTrue(data.length > 0);
     }
 
     @Test
-public void WhenDeserialize_UsingJSONDecoder_ActualAndExpectedObjectsAreEqual(){
+    public void WhenDeserializeUsingJSONDecoder_thenActualAndExpectedObjectsAreEqual() {
         byte[] data = serealizer.serealizeAvroHttpRequestJSON(request);
         AvroHttpRequest actualRequest = deSerealizer.deSerealizeAvroHttpRequestJSON(data);
         assertEquals(actualRequest, request);
-    assertTrue(actualRequest.getRequestTime().equals(request.getRequestTime()));
+        assertTrue(actualRequest.getRequestTime()
+            .equals(request.getRequestTime()));
     }
 
     @Test
-public void WhenDeserialize_UsingBinaryecoder_ActualAndExpectedObjectsAreEqual(){
+    public void WhenDeserializeUsingBinaryecoder_thenActualAndExpectedObjectsAreEqual() {
         byte[] data = serealizer.serealizeAvroHttpRequestBinary(request);
         AvroHttpRequest actualRequest = deSerealizer.deSerealizeAvroHttpRequestBinary(data);
         assertEquals(actualRequest, request);
-    assertTrue(actualRequest.getRequestTime().equals(request.getRequestTime()));
+        assertTrue(actualRequest.getRequestTime()
-}
+            .equals(request.getRequestTime()));
+    }
+    
 }
 

apache-fop/src/main/resources/logback.xml

@@ -2,7 +2,7 @@
 <configuration>
     <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
         <encoder>
-            <pattern>web - %date [%thread] %-5level %logger{36} - %message%n
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
             </pattern>
         </encoder>
     </appender>

apache-thrift/pom.xml

@@ -39,6 +39,7 @@
             <plugin>
                 <groupId>org.codehaus.mojo</groupId>
                 <artifactId>build-helper-maven-plugin</artifactId>
+                <version>${build-helper-maven-plugin.version}</version>
                 <executions>
                     <execution>
                         <phase>generate-sources</phase>
@@ -60,6 +61,7 @@
         <thrift.version>0.10.0</thrift.version>
         <maven-thrift.version>0.1.11</maven-thrift.version>
         <org.slf4j.slf4j-simple.version>1.7.12</org.slf4j.slf4j-simple.version>
+        <build-helper-maven-plugin.version>3.0.0</build-helper-maven-plugin.version>
     </properties>
 
 </project>

apache-velocity/src/main/resources/logback.xml

@@ -2,7 +2,7 @@
 <configuration>
     <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
         <encoder>
-            <pattern>web - %date [%thread] %-5level %logger{36} - %message%n
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
             </pattern>
         </encoder>
     </appender>

aws/pom.xml

@@ -137,7 +137,7 @@
         <aws-lambda-java-core.version>1.1.0</aws-lambda-java-core.version>
         <gson.version>2.8.0</gson.version>
         <aws-java-sdk.version>1.11.290</aws-java-sdk.version>
-        <mockito-core.version>2.8.9</mockito-core.version>
+        <mockito-core.version>2.21.0</mockito-core.version>
         <assertj-core.version>3.8.0</assertj-core.version>
         <dynamodblocal.version>1.11.86</dynamodblocal.version>
         <dynamodblocal.repository.url>https://s3-us-west-2.amazonaws.com/dynamodb-local/release</dynamodblocal.repository.url>

core-java-8/README.md

@@ -9,54 +9,30 @@
 - [Java 8 New Features](http://www.baeldung.com/java-8-new-features)
 - [Lambda Expressions and Functional Interfaces: Tips and Best Practices](http://www.baeldung.com/java-8-lambda-expressions-tips)
 - [The Double Colon Operator in Java 8](http://www.baeldung.com/java-8-double-colon-operator)
-- [Java 8 Streams Advanced](http://www.baeldung.com/java-8-streams)
-- [Introduction to Java 8 Streams](http://www.baeldung.com/java-8-streams-introduction)
 - [Guide to Java 8 groupingBy Collector](http://www.baeldung.com/java-groupingby-collector)
 - [Strategy Design Pattern in Java 8](http://www.baeldung.com/java-strategy-pattern)
-- [Java 8 and Infinite Streams](http://www.baeldung.com/java-inifinite-streams)
-- [String Operations with Java Streams](http://www.baeldung.com/java-stream-operations-on-strings)
 - [Exceptions in Java 8 Lambda Expressions](http://www.baeldung.com/java-lambda-exceptions)
-- [Java 8 Stream findFirst() vs. findAny()](http://www.baeldung.com/java-stream-findfirst-vs-findany)
 - [Guide to Java 8 Comparator.comparing()](http://www.baeldung.com/java-8-comparator-comparing)
-- [How to Get the Last Element of a Stream in Java?](http://www.baeldung.com/java-stream-last-element)
-- [Introduction to the Java 8 Date/Time API](http://www.baeldung.com/java-8-date-time-intro)
-- [Migrating to the New Java 8 Date Time API](http://www.baeldung.com/migrating-to-java-8-date-time-api)
 - [Guide To Java 8 Optional](http://www.baeldung.com/java-optional)
 - [Guide to the Java 8 forEach](http://www.baeldung.com/foreach-java)
-- [Get the Current Date, Time and Timestamp in Java 8](http://www.baeldung.com/current-date-time-and-timestamp-in-java-8)
-- [TemporalAdjuster in Java](http://www.baeldung.com/java-temporal-adjuster)
 - [Finding Max/Min of a List or Collection](http://www.baeldung.com/java-collection-min-max)
 - [Java Base64 Encoding and Decoding](http://www.baeldung.com/java-base64-encode-and-decode)
 - [The Difference Between map() and flatMap()](http://www.baeldung.com/java-difference-map-and-flatmap)
-- [Merging Streams in Java](http://www.baeldung.com/java-merge-streams)
-- [“Stream has already been operated upon or closed” Exception in Java](http://www.baeldung.com/java-stream-operated-upon-or-closed-exception)
-- [Display All Time Zones With GMT And UTC in Java](http://www.baeldung.com/java-time-zones)
 - [Copy a File with Java](http://www.baeldung.com/java-copy-file)
 - [Static and Default Methods in Interfaces in Java](http://www.baeldung.com/java-static-default-methods)
-- [Iterable to Stream in Java](http://www.baeldung.com/java-iterable-to-stream)
-- [Converting String to Stream of chars](http://www.baeldung.com/java-string-to-stream)
-- [How to Iterate Over a Stream With Indices](http://www.baeldung.com/java-stream-indices)
 - [Efficient Word Frequency Calculator in Java](http://www.baeldung.com/java-word-frequency)
-- [Primitive Type Streams in Java 8](http://www.baeldung.com/java-8-primitive-streams)
 - [Fail-Safe Iterator vs Fail-Fast Iterator](http://www.baeldung.com/java-fail-safe-vs-fail-fast-iterator)
 - [Shuffling Collections In Java](http://www.baeldung.com/java-shuffle-collection)
-- [Java 8 StringJoiner](http://www.baeldung.com/java-string-joiner)
 - [Introduction to Spliterator in Java](http://www.baeldung.com/java-spliterator)
 - [Java 8 Math New Methods](http://www.baeldung.com/java-8-math)
 - [Overview of Java Built-in Annotations](http://www.baeldung.com/java-default-annotations)
 - [Finding Min/Max in an Array with Java](http://www.baeldung.com/java-array-min-max)
 - [Internationalization and Localization in Java 8](http://www.baeldung.com/java-8-localization)
 - [How to Find an Element in a List with Java](http://www.baeldung.com/find-list-element-java)
-- [Measure Elapsed Time in Java](http://www.baeldung.com/java-measure-elapsed-time)
 - [Java Optional – orElse() vs orElseGet()](http://www.baeldung.com/java-optional-or-else-vs-or-else-get)
 - [An Introduction to Java.util.Hashtable Class](http://www.baeldung.com/java-hash-table)
 - [Method Parameter Reflection in Java](http://www.baeldung.com/java-parameter-reflection)
 - [Java 8 Unsigned Arithmetic Support](http://www.baeldung.com/java-unsigned-arithmetic)
-- [How to Get the Start and the End of a Day using Java](http://www.baeldung.com/java-day-start-end)
 - [Generalized Target-Type Inference in Java](http://www.baeldung.com/java-generalized-target-type-inference)
-- [Image to Base64 String Conversion](http://www.baeldung.com/java-base64-image-string)
-- [Calculate Age in Java](http://www.baeldung.com/java-get-age)
 - [Copy a List to Another List in Java](http://www.baeldung.com/java-copy-list-to-another)
-- [Increment Date in Java](http://www.baeldung.com/java-increment-date)
-- [Add Hours To a Date In Java](http://www.baeldung.com/java-add-hours-date)
 - [Overriding System Time for Testing in Java](http://www.baeldung.com/java-override-system-time)

core-java-8/pom.xml

@@ -89,11 +89,6 @@
             <artifactId>vavr</artifactId>
             <version>${vavr.version}</version>
         </dependency>
-        <dependency>
-            <groupId>one.util</groupId>
-            <artifactId>streamex</artifactId>
-            <version>${streamex.version}</version>
-        </dependency>
         <dependency>
             <groupId>joda-time</groupId>
             <artifactId>joda-time</artifactId>
@@ -151,6 +146,7 @@
             <plugin>
                 <groupId>org.springframework.boot</groupId>
                 <artifactId>spring-boot-maven-plugin</artifactId>
+                <version>${spring-boot-maven-plugin.version}</version>
                 <executions>
                     <execution>
                         <goals>
@@ -176,7 +172,6 @@
         <lombok.version>1.16.12</lombok.version>
         <vavr.version>0.9.0</vavr.version>
         <protonpack.version>1.13</protonpack.version>
-        <streamex.version>0.6.5</streamex.version>
         <joda.version>2.10</joda.version>
         <!-- testing -->
         <assertj.version>3.6.1</assertj.version>
@@ -184,6 +179,6 @@
         <avaitility.version>1.7.0</avaitility.version>
         <jmh-core.version>1.19</jmh-core.version>
         <jmh-generator.version>1.19</jmh-generator.version>
+        <spring-boot-maven-plugin.version>2.0.4.RELEASE</spring-boot-maven-plugin.version>
     </properties>
-
 </project>

core-java-8/src/main/java/com/baeldung/optional/PersonRepository.java

@@ -0,0 +1,9 @@
+package com.baeldung.optional;
+
+public class PersonRepository {
+
+    public String findNameById(String id) {
+        return id == null ? null : "Name";
+    }
+
+}

core-java-8/src/main/java/com/baeldung/primitive/BenchmarkRunner.java

@@ -0,0 +1,23 @@
+package com.baeldung.primitive;
+
+public class BenchmarkRunner {
+
+    public static void main(String[] args) throws Exception {
+        new IntPrimitiveLookup().run();
+        new IntegerWrapperLookup().run();
+        new FloatPrimitiveLookup().run();
+        new FloatWrapperLookup().run();
+        new DoublePrimitiveLookup().run();
+        new DoubleWrapperLookup().run();
+        new ShortPrimitiveLookup().run();
+        new ShortWrapperLookup().run();
+        new BooleanPrimitiveLookup().run();
+        new BooleanWrapperLookup().run();
+        new CharPrimitiveLookup().run();
+        new CharacterWrapperLookup().run();
+        new BytePrimitiveLookup().run();
+        new ByteWrapperLookup().run();
+        new LongPrimitiveLookup().run();
+        new LongWrapperLookup().run();
+    }
+}

core-java-8/src/main/java/com/baeldung/primitive/BooleanPrimitiveLookup.java

@@ -0,0 +1,45 @@
+package com.baeldung.primitive;
+
+import org.openjdk.jmh.annotations.*;
+
+@State(Scope.Thread)
+public class BooleanPrimitiveLookup extends Lookup {
+
+    private boolean[] elements;
+    private final boolean pivot = false;
+
+    @Setup
+    @Override
+    public void prepare() {
+        elements = new boolean[s];
+        for (int i = 0; i < s - 1; i++) {
+            elements[i] = true;
+        }
+        elements[s - 1] = pivot;
+    }
+
+    @TearDown
+    @Override
+    public void clean() {
+        elements = null;
+    }
+
+
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public int findPosition() {
+        int index = 0;
+        while (pivot != elements[index]) {
+            index++;
+        }
+        return index;
+    }
+
+    @Override
+    public String getSimpleClassName() {
+        return BooleanPrimitiveLookup.class.getSimpleName();
+    }
+
+
+
+}

core-java-8/src/main/java/com/baeldung/primitive/BooleanWrapperLookup.java

@@ -0,0 +1,45 @@
+package com.baeldung.primitive;
+
+import org.openjdk.jmh.annotations.*;
+
+@State(Scope.Thread)
+public class BooleanWrapperLookup extends Lookup {
+    private Boolean[] elements;
+    private final boolean pivot = false;
+
+    @Override
+    @Setup
+    public void prepare() {
+        elements = new Boolean[s];
+        for (int i = 0; i < s - 1; i++) {
+            elements[i] = true;
+        }
+        elements[s - 1] = pivot;
+    }
+
+    @Override
+    @TearDown
+    public void clean() {
+        elements = null;
+    }
+
+    @Override
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public int findPosition() {
+        int index = 0;
+        Boolean pivotWrapper = pivot;
+        while (!pivotWrapper.equals(elements[index])) {
+            index++;
+        }
+        return index;
+
+    }
+
+    @Override
+    public String getSimpleClassName() {
+        return BooleanWrapperLookup.class.getSimpleName();
+    }
+
+
+}

core-java-8/src/main/java/com/baeldung/primitive/BytePrimitiveLookup.java

@@ -0,0 +1,46 @@
+package com.baeldung.primitive;
+
+import org.openjdk.jmh.annotations.*;
+
+@State(Scope.Thread)
+public class BytePrimitiveLookup extends Lookup {
+
+    private byte[] elements;
+    private final byte pivot = 2;
+
+    @Setup
+    @Override
+    public void prepare() {
+        byte common = 1;
+        elements = new byte[s];
+        for (int i = 0; i < s - 1; i++) {
+            elements[i] = common;
+        }
+        elements[s - 1] = pivot;
+    }
+
+    @TearDown
+    @Override
+    public void clean() {
+        elements = null;
+    }
+
+
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public int findPosition() {
+        int index = 0;
+        while (pivot != elements[index]) {
+            index++;
+        }
+        return index;
+    }
+
+    @Override
+    public String getSimpleClassName() {
+        return BytePrimitiveLookup.class.getSimpleName();
+    }
+
+
+
+}

core-java-8/src/main/java/com/baeldung/primitive/ByteWrapperLookup.java

@@ -0,0 +1,46 @@
+package com.baeldung.primitive;
+
+import org.openjdk.jmh.annotations.*;
+
+@State(Scope.Thread)
+public class ByteWrapperLookup extends Lookup {
+    private Byte[] elements;
+    private final byte pivot = 2;
+
+    @Override
+    @Setup
+    public void prepare() {
+        byte common = 1;
+        elements = new Byte[s];
+        for (int i = 0; i < s - 1; i++) {
+            elements[i] = common;
+        }
+        elements[s - 1] = pivot;
+    }
+
+    @Override
+    @TearDown
+    public void clean() {
+        elements = null;
+    }
+
+    @Override
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public int findPosition() {
+        int index = 0;
+        Byte pivotWrapper = pivot;
+        while (!pivotWrapper.equals(elements[index])) {
+            index++;
+        }
+        return index;
+
+    }
+
+    @Override
+    public String getSimpleClassName() {
+        return ByteWrapperLookup.class.getSimpleName();
+    }
+
+
+}

core-java-8/src/main/java/com/baeldung/primitive/CharPrimitiveLookup.java

@@ -0,0 +1,46 @@
+package com.baeldung.primitive;
+
+import org.openjdk.jmh.annotations.*;
+
+@State(Scope.Thread)
+public class CharPrimitiveLookup extends Lookup {
+
+    private char[] elements;
+    private final char pivot = 'b';
+
+    @Setup
+    @Override
+    public void prepare() {
+        char common = 'a';
+        elements = new char[s];
+        for (int i = 0; i < s - 1; i++) {
+            elements[i] = common;
+        }
+        elements[s - 1] = pivot;
+    }
+
+    @TearDown
+    @Override
+    public void clean() {
+        elements = null;
+    }
+
+
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public int findPosition() {
+        int index = 0;
+        while (pivot != elements[index]) {
+            index++;
+        }
+        return index;
+    }
+
+    @Override
+    public String getSimpleClassName() {
+        return CharPrimitiveLookup.class.getSimpleName();
+    }
+
+
+
+}

core-java-8/src/main/java/com/baeldung/primitive/CharacterWrapperLookup.java

@@ -0,0 +1,46 @@
+package com.baeldung.primitive;
+
+import org.openjdk.jmh.annotations.*;
+
+@State(Scope.Thread)
+public class CharacterWrapperLookup extends Lookup {
+    private Character[] elements;
+    private final char pivot = 'b';
+
+    @Override
+    @Setup
+    public void prepare() {
+        char common = 'a';
+        elements = new Character[s];
+        for (int i = 0; i < s - 1; i++) {
+            elements[i] = common;
+        }
+        elements[s - 1] = pivot;
+    }
+
+    @Override
+    @TearDown
+    public void clean() {
+        elements = null;
+    }
+
+    @Override
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public int findPosition() {
+        int index = 0;
+        Character pivotWrapper = pivot;
+        while (!pivotWrapper.equals(elements[index])) {
+            index++;
+        }
+        return index;
+
+    }
+
+    @Override
+    public String getSimpleClassName() {
+        return CharacterWrapperLookup.class.getSimpleName();
+    }
+
+
+}

core-java-8/src/main/java/com/baeldung/primitive/DoublePrimitiveLookup.java

@@ -0,0 +1,42 @@
+package com.baeldung.primitive;
+
+import org.openjdk.jmh.annotations.*;
+
+@State(Scope.Thread)
+public class DoublePrimitiveLookup extends Lookup {
+    private double[] elements;
+    private final double pivot = 2;
+
+    @Setup
+    @Override
+    public void prepare() {
+        double common = 1;
+        elements = new double[s];
+        for (int i = 0; i < s - 1; i++) {
+            elements[i] = common;
+        }
+        elements[s - 1] = pivot;
+    }
+
+    @TearDown
+    @Override
+    public void clean() {
+        elements = null;
+    }
+
+
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public int findPosition() {
+        int index = 0;
+        while (pivot != elements[index]) {
+            index++;
+        }
+        return index;
+    }
+
+    @Override
+    public String getSimpleClassName() {
+        return DoublePrimitiveLookup.class.getSimpleName();
+    }
+}

core-java-8/src/main/java/com/baeldung/primitive/DoubleWrapperLookup.java

@@ -0,0 +1,45 @@
+package com.baeldung.primitive;
+
+import org.openjdk.jmh.annotations.*;
+
+@State(Scope.Thread)
+public class DoubleWrapperLookup extends Lookup {
+    private Double[] elements;
+    private final double pivot = 2d;
+
+    @Override
+    @Setup
+    public void prepare() {
+        double common = 1;
+        elements = new Double[s];
+        for (int i = 0; i < s - 1; i++) {
+            elements[i] = common;
+        }
+        elements[s - 1] = pivot;
+    }
+
+    @Override
+    @TearDown
+    public void clean() {
+        elements = null;
+    }
+
+    @Override
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public int findPosition() {
+        int index = 0;
+        Double pivotWrapper = pivot;
+        while (!pivotWrapper.equals(elements[index])) {
+            index++;
+        }
+        return index;
+
+    }
+
+    @Override
+    public String getSimpleClassName() {
+        return DoubleWrapperLookup.class.getSimpleName();
+    }
+
+}

core-java-8/src/main/java/com/baeldung/primitive/FloatPrimitiveLookup.java

@@ -0,0 +1,42 @@
+package com.baeldung.primitive;
+
+import org.openjdk.jmh.annotations.*;
+
+@State(Scope.Thread)
+public class FloatPrimitiveLookup extends Lookup {
+    private float[] elements;
+    private final float pivot = 2;
+
+    @Setup
+    @Override
+    public void prepare() {
+        int common = 1;
+        elements = new float[s];
+        for (int i = 0; i < s - 1; i++) {
+            elements[i] = common;
+        }
+        elements[s - 1] = pivot;
+    }
+
+    @TearDown
+    @Override
+    public void clean() {
+        elements = null;
+    }
+
+
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public int findPosition() {
+        int index = 0;
+        while (pivot != elements[index]) {
+            index++;
+        }
+        return index;
+    }
+
+    @Override
+    public String getSimpleClassName() {
+        return FloatPrimitiveLookup.class.getSimpleName();
+    }
+}

core-java-8/src/main/java/com/baeldung/primitive/FloatWrapperLookup.java

@@ -0,0 +1,43 @@
+package com.baeldung.primitive;
+
+import org.openjdk.jmh.annotations.*;
+
+@State(Scope.Thread)
+public class FloatWrapperLookup extends Lookup {
+    private Float[] elements;
+    private final float pivot = 2;
+
+    @Override
+    @Setup
+    public void prepare() {
+        float common = 1;
+        elements = new Float[s];
+        for (int i = 0; i < s - 1; i++) {
+            elements[i] = common;
+        }
+        elements[s - 1] = pivot;
+    }
+
+    @Override
+    @TearDown
+    public void clean() {
+        elements = null;
+    }
+
+    @Override
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public int findPosition() {
+        int index = 0;
+        Float pivotWrapper = pivot;
+        while (!pivotWrapper.equals(elements[index])) {
+            index++;
+        }
+        return index;
+    }
+
+    @Override
+    public String getSimpleClassName() {
+        return FloatWrapperLookup.class.getSimpleName();
+    }
+}

core-java-8/src/main/java/com/baeldung/primitive/IntPrimitiveLookup.java

@@ -0,0 +1,45 @@
+package com.baeldung.primitive;
+
+import org.openjdk.jmh.annotations.*;
+
+@State(Scope.Thread)
+public class IntPrimitiveLookup extends Lookup {
+
+    private int[] elements;
+    private final int pivot = 2;
+
+    @Setup
+    @Override
+    public void prepare() {
+        int common = 1;
+        elements = new int[s];
+        for (int i = 0; i < s - 1; i++) {
+            elements[i] = common;
+        }
+        elements[s - 1] = pivot;
+    }
+
+    @TearDown
+    @Override
+    public void clean() {
+        elements = null;
+    }
+
+
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public int findPosition() {
+        int index = 0;
+        while (pivot != elements[index]) {
+            index++;
+        }
+        return index;
+    }
+
+    @Override
+    public String getSimpleClassName() {
+        return IntPrimitiveLookup.class.getSimpleName();
+    }
+
+
+}

core-java-8/src/main/java/com/baeldung/primitive/IntegerWrapperLookup.java

@@ -0,0 +1,45 @@
+package com.baeldung.primitive;
+
+import org.openjdk.jmh.annotations.*;
+
+@State(Scope.Thread)
+public class IntegerWrapperLookup extends Lookup {
+    private Integer[] elements;
+    private final int pivot = 2;
+
+    @Override
+    @Setup
+    public void prepare() {
+        int common = 1;
+        elements = new Integer[s];
+        for (int i = 0; i < s - 1; i++) {
+            elements[i] = common;
+        }
+        elements[s - 1] = pivot;
+    }
+
+    @Override
+    @TearDown
+    public void clean() {
+        elements = null;
+    }
+
+    @Override
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public int findPosition() {
+        int index = 0;
+        Integer pivotWrapper = pivot;
+        while (!pivotWrapper.equals(elements[index])) {
+            index++;
+        }
+        return index;
+
+    }
+
+    @Override
+    public String getSimpleClassName() {
+        return IntegerWrapperLookup.class.getSimpleName();
+    }
+
+}

core-java-8/src/main/java/com/baeldung/primitive/LongPrimitiveLookup.java

@@ -0,0 +1,42 @@
+package com.baeldung.primitive;
+
+import org.openjdk.jmh.annotations.*;
+
+@State(Scope.Thread)
+public class LongPrimitiveLookup extends Lookup {
+    private long[] elements;
+    private final long pivot = 2;
+
+    @Setup
+    @Override
+    public void prepare() {
+        long common = 1;
+        elements = new long[s];
+        for (int i = 0; i < s - 1; i++) {
+            elements[i] = common;
+        }
+        elements[s - 1] = pivot;
+    }
+
+    @TearDown
+    @Override
+    public void clean() {
+        elements = null;
+    }
+
+
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public int findPosition() {
+        int index = 0;
+        while (pivot != elements[index]) {
+            index++;
+        }
+        return index;
+    }
+
+    @Override
+    public String getSimpleClassName() {
+        return LongPrimitiveLookup.class.getSimpleName();
+    }
+}

core-java-8/src/main/java/com/baeldung/primitive/LongWrapperLookup.java

@@ -0,0 +1,45 @@
+package com.baeldung.primitive;
+
+import org.openjdk.jmh.annotations.*;
+
+@State(Scope.Thread)
+public class LongWrapperLookup extends Lookup{
+    private Long[] elements;
+    private final long pivot = 2;
+
+    @Override
+    @Setup
+    public void prepare() {
+        long common = 1;
+        elements = new Long[s];
+        for (int i = 0; i < s - 1; i++) {
+            elements[i] = common;
+        }
+        elements[s - 1] = pivot;
+    }
+
+    @Override
+    @TearDown
+    public void clean() {
+        elements = null;
+    }
+
+    @Override
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public int findPosition() {
+        int index = 0;
+        Long pivotWrapper = pivot;
+        while (!pivotWrapper.equals(elements[index])) {
+            index++;
+        }
+        return index;
+
+    }
+
+    @Override
+    public String getSimpleClassName() {
+        return LongWrapperLookup.class.getSimpleName();
+    }
+
+}

core-java-8/src/main/java/com/baeldung/primitive/Lookup.java

@@ -0,0 +1,56 @@
+package com.baeldung.primitive;
+
+import org.openjdk.jmh.results.RunResult;
+import org.openjdk.jmh.runner.Runner;
+import org.openjdk.jmh.runner.RunnerException;
+import org.openjdk.jmh.runner.options.Options;
+import org.openjdk.jmh.runner.options.OptionsBuilder;
+
+import java.util.Collection;
+
+/**
+ * An abstract class that is to be extended by the classes that
+ * perform lookup in the arrays either of Java primitive types or their wrappers.
+ */
+public abstract class Lookup {
+    /**
+     * the array size
+     */
+    final protected int s = 50000000;
+
+    /**
+     * Initialize the array: fill in the array with the same
+     * elements except for the last one.
+     */
+    abstract public void prepare();
+
+    /**
+     * Free the array's reference.
+     */
+    abstract public void clean();
+
+    /**
+     * Find the position of the element that is different from the others.
+     * By construction, it is the last array element.
+     *
+     * @return array's last element index
+     */
+    abstract public int findPosition();
+
+    /**
+     * Get the name of the class that extends this one. It is needed in order
+     * to set up the benchmark.
+     *
+     * @return
+     */
+    abstract public String getSimpleClassName();
+
+    Collection<RunResult> run() throws RunnerException {
+        Options opt = new OptionsBuilder()
+                .include(getSimpleClassName())
+                .forks(1)
+                .build();
+        return new Runner(opt).run();
+    }
+
+}

core-java-8/src/main/java/com/baeldung/primitive/ShortPrimitiveLookup.java

@@ -0,0 +1,45 @@
+package com.baeldung.primitive;
+
+import org.openjdk.jmh.annotations.*;
+
+@State(Scope.Thread)
+public class ShortPrimitiveLookup extends Lookup {
+
+    private short[] elements;
+    private final short pivot = 2;
+
+    @Setup
+    @Override
+    public void prepare() {
+        short common = 1;
+        elements = new short[s];
+        for (int i = 0; i < s - 1; i++) {
+            elements[i] = common;
+        }
+        elements[s - 1] = pivot;
+    }
+
+    @TearDown
+    @Override
+    public void clean() {
+        elements = null;
+    }
+
+
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public int findPosition() {
+        int index = 0;
+        while (pivot != elements[index]) {
+            index++;
+        }
+        return index;
+    }
+
+    @Override
+    public String getSimpleClassName() {
+        return ShortPrimitiveLookup.class.getSimpleName();
+    }
+
+
+}

core-java-8/src/main/java/com/baeldung/primitive/ShortWrapperLookup.java

@@ -0,0 +1,46 @@
+package com.baeldung.primitive;
+
+import org.openjdk.jmh.annotations.*;
+
+@State(Scope.Thread)
+public class ShortWrapperLookup extends Lookup {
+    private Short[] elements;
+    private final short pivot = 2;
+
+    @Override
+    @Setup
+    public void prepare() {
+        short common = 1;
+        elements = new Short[s];
+        for (int i = 0; i < s - 1; i++) {
+            elements[i] = common;
+        }
+        elements[s - 1] = pivot;
+    }
+
+    @Override
+    @TearDown
+    public void clean() {
+        elements = null;
+    }
+
+    @Override
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public int findPosition() {
+        int index = 0;
+        Short pivotWrapper = pivot;
+        while (!pivotWrapper.equals(elements[index])) {
+            index++;
+        }
+        return index;
+
+    }
+
+    @Override
+    public String getSimpleClassName() {
+        return ShortWrapperLookup.class.getSimpleName();
+    }
+
+
+}

core-java-8/src/test/java/com/baeldung/optional/PersonRepositoryUnitTest.java

@@ -0,0 +1,43 @@
+package com.baeldung.optional;
+
+import org.junit.Test;
+
+import java.util.Optional;
+
+import static org.junit.jupiter.api.Assertions.assertAll;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+public class PersonRepositoryUnitTest {
+
+    PersonRepository personRepository = new PersonRepository();
+
+    @Test
+    public void whenIdIsNull_thenExceptionIsThrown() {
+        assertThrows(IllegalArgumentException.class,
+                () ->
+                        Optional
+                                .ofNullable(personRepository.findNameById(null))
+                                .orElseThrow(IllegalArgumentException::new));
+    }
+
+    @Test
+    public void whenIdIsNonNull_thenNoExceptionIsThrown() {
+        assertAll(
+                () ->
+                        Optional
+                                .ofNullable(personRepository.findNameById("id"))
+                                .orElseThrow(RuntimeException::new));
+    }
+
+    @Test
+    public void whenIdNonNull_thenReturnsNameUpperCase() {
+        String name = Optional
+                .ofNullable(personRepository.findNameById("id"))
+                .map(String::toUpperCase)
+                .orElseThrow(RuntimeException::new);
+
+        assertEquals("NAME", name);
+    }
+
+}

core-java-8/src/test/java/com/baeldung/streamordering/BenchmarkUnitTest.java

@@ -0,0 +1,97 @@
+package com.baeldung.streamordering;
+
+import org.junit.Test;
+import org.openjdk.jmh.annotations.*;
+import org.openjdk.jmh.infra.Blackhole;
+import org.openjdk.jmh.runner.Runner;
+import org.openjdk.jmh.runner.options.Options;
+import org.openjdk.jmh.runner.options.OptionsBuilder;
+import org.openjdk.jmh.runner.options.TimeValue;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Random;
+import java.util.concurrent.TimeUnit;
+import java.util.stream.IntStream;
+
+
+public class BenchmarkUnitTest
+{
+
+  @Test
+  public void
+  launchBenchmark() throws Exception {
+
+    Options opt = new OptionsBuilder()
+      // Specify which benchmarks to run.
+      // You can be more specific if you'd like to run only one benchmark per test.
+      .include(this.getClass().getName() + ".*")
+      // Set the following options as needed
+      .mode (Mode.AverageTime)
+      .timeUnit(TimeUnit.MICROSECONDS)
+      .warmupTime(TimeValue.seconds(1))
+      .warmupIterations(2)
+      .measurementTime(TimeValue.seconds(1))
+      .measurementIterations(2)
+      .threads(2)
+      .forks(1)
+      .shouldFailOnError(true)
+      .shouldDoGC(true)
+      //.jvmArgs("-XX:+UnlockDiagnosticVMOptions", "-XX:+PrintInlining")
+      //.addProfiler(WinPerfAsmProfiler.class)
+      .build();
+
+    new Runner(opt).run();
+
+
+  }
+
+  @Benchmark
+  public void givenOrderedStreamInput_whenStreamFiltered_showOpsPerMS(){
+    IntStream.range(1, 100_000_000).parallel().filter(i -> i % 10 == 0).toArray();
+  }
+
+  @Benchmark
+  public void givenUnorderedStreamInput_whenStreamFiltered_showOpsPerMS(){
+    IntStream.range(1,100_000_000).unordered().parallel().filter(i -> i % 10 == 0).toArray();
+  }
+
+  @Benchmark
+  public void givenUnorderedStreamInput_whenStreamDistinct_showOpsPerMS(){
+    IntStream.range(1, 1_000_000).unordered().parallel().distinct().toArray();
+  }
+
+  @Benchmark
+  public void givenOrderedStreamInput_whenStreamDistinct_showOpsPerMS() {
+    //section 5.1.
+    IntStream.range(1, 1_000_000).parallel().distinct().toArray();
+  }
+
+
+  // The JMH samples are the best documentation for how to use it
+  // http://hg.openjdk.java.net/code-tools/jmh/file/tip/jmh-samples/src/main/java/org/openjdk/jmh/samples/
+  @State(Scope.Thread)
+  public static class BenchmarkState
+  {
+    List<Integer> list;
+
+    @Setup(Level.Trial) public void
+    initialize() {
+
+      Random rand = new Random();
+
+      list = new ArrayList<>();
+      for (int i = 0; i < 1000; i++)
+        list.add (rand.nextInt());
+    }
+  }
+
+  @Benchmark public void
+  benchmark1 (BenchmarkState state, Blackhole bh) {
+
+    List<Integer> list = state.list;
+
+    for (int i = 0; i < 1000; i++)
+      bh.consume (list.get (i));
+  }
+}

core-java-8/src/test/java/com/baeldung/streamordering/StreamsOrderingUnitTest.java

@@ -0,0 +1,149 @@
+package com.baeldung.streamordering;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import java.util.*;
+import java.util.function.Function;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+
+import static org.junit.Assert.assertEquals;
+
+public class StreamsOrderingUnitTest {
+
+  Logger logger = Logger.getLogger( StreamsOrderingUnitTest.class.getName());
+
+  @Before
+  public void setUp() throws Exception {
+    logger.setLevel(Level.ALL);
+  }
+
+  @Test
+  public void givenTwoCollections_whenStreamed_thenCheckOutputDifferent(){
+
+    List<String> list = Arrays.asList("B", "A", "C", "D", "F");
+    Set<String> set = new TreeSet<>(Arrays.asList("B", "A", "C", "D", "F"));
+
+    Object[] listOutput = list.stream().toArray();
+    Object[] setOutput = set.stream().toArray();
+
+    assertEquals("[B, A, C, D, F]", Arrays.toString(listOutput));
+    assertEquals("[A, B, C, D, F]", Arrays.toString(setOutput));
+
+  }
+
+  @Test
+  public void givenTwoCollections_whenStreamedInParallel_thenCheckOutputDifferent(){
+
+    List<String> list = Arrays.asList("B", "A", "C", "D", "F");
+    Set<String> set = new TreeSet<>(Arrays.asList("B", "A", "C", "D", "F"));
+
+    Object[] listOutput = list.stream().parallel().toArray();
+    Object[] setOutput = set.stream().parallel().toArray();
+
+    assertEquals("[B, A, C, D, F]", Arrays.toString(listOutput));
+    assertEquals("[A, B, C, D, F]", Arrays.toString(setOutput));
+
+  }
+
+
+
+  @Test
+  public void givenOrderedInput_whenUnorderedAndOrderedCompared_thenCheckUnorderedOutputChanges(){
+    Set<Integer> set = new TreeSet<>(
+      Arrays.asList(-9, -5, -4, -2, 1, 2, 4, 5, 7, 9, 12, 13, 16, 29, 23, 34, 57, 68, 90, 102, 230));
+
+      Object[] orderedArray = set.stream()
+        .parallel()
+        .limit(5)
+        .toArray();
+      Object[] unorderedArray = set.stream()
+        .unordered()
+        .parallel()
+        .limit(5)
+        .toArray();
+
+     logger.info(Arrays.toString(orderedArray));
+     logger.info(Arrays.toString(unorderedArray));
+  }
+
+
+  @Test
+  public void givenUnsortedStreamInput_whenStreamSorted_thenCheckOrderChanged(){
+
+    List<Integer> list = Arrays.asList(-3,10,-4,1,3);
+
+    Object[] listOutput = list.stream().toArray();
+    Object[] listOutputSorted = list.stream().sorted().toArray();
+
+    assertEquals("[-3, 10, -4, 1, 3]", Arrays.toString(listOutput));
+    assertEquals("[-4, -3, 1, 3, 10]", Arrays.toString(listOutputSorted));
+
+  }
+
+  @Test
+  public void givenUnsortedStreamInput_whenStreamDistinct_thenShowTimeTaken(){
+    long start, end;
+    start = System.currentTimeMillis();
+    IntStream.range(1,1_000_000).unordered().parallel().distinct().toArray();
+    end = System.currentTimeMillis();
+    System.out.println(String.format("Time taken when unordered: %d ms", (end - start)));
+  }
+
+
+  @Test
+  public void givenSameCollection_whenStreamTerminated_thenCheckEachVsEachOrdered(){
+
+    List<String> list = Arrays.asList("B", "A", "C", "D", "F");
+
+    list.stream().parallel().forEach(e -> logger.log(Level.INFO, e));
+    list.stream().parallel().forEachOrdered(e -> logger.log(Level.INFO, e));
+
+  }
+
+  @Test
+  public void givenSameCollection_whenStreamCollected_thenCheckOutput(){
+
+    List<String> list = Arrays.asList("B", "A", "C", "D", "F");
+
+    List<String> collectionList = list.stream().parallel().collect(Collectors.toList());
+    Set<String> collectionSet = list.stream().parallel().collect(Collectors.toCollection(TreeSet::new));
+
+    assertEquals("[B, A, C, D, F]", collectionList.toString());
+    assertEquals("[A, B, C, D, F]", collectionSet.toString());
+
+  }
+
+
+  @Test
+  public void givenListIterationOrder_whenStreamCollectedToMap_thenCeckOrderChanged() {
+    List<String> list = Arrays.asList("A", "BB", "CCC");
+
+    Map<String, Integer> hashMap = list.stream().collect(Collectors.toMap(Function.identity(), String::length));
+
+    Object[] keySet = hashMap.keySet().toArray();
+
+    assertEquals("[BB, A, CCC]", Arrays.toString(keySet));
+
+  }
+
+  @Test
+  public void givenListIteration_whenStreamCollectedtoHashMap_thenCheckOrderMaintained() {
+    List<String> list = Arrays.asList("A", "BB", "CCC", "CCC");
+
+    Map<String, Integer> linkedHashMap = list.stream().collect(Collectors.toMap(
+      Function.identity(),
+      String::length,
+      (u, v) -> u,
+      LinkedHashMap::new
+    ));
+
+    Object[] keySet = linkedHashMap.keySet().toArray();
+
+    assertEquals("[A, BB, CCC]", Arrays.toString(keySet));
+  }
+
+}

core-java-9/README.md

@@ -15,10 +15,7 @@
 - [Introduction to Project Jigsaw](http://www.baeldung.com/project-jigsaw-java-modularity)
 - [Java 9 Optional API Additions](http://www.baeldung.com/java-9-optional)
 - [Java 9 Reactive Streams](http://www.baeldung.com/java-9-reactive-streams)
-- [How to Get All Dates Between Two Dates?](http://www.baeldung.com/java-between-dates)
 - [Java 9 java.util.Objects Additions](http://www.baeldung.com/java-9-objects-new)
-- [Compact Strings in Java 9](http://www.baeldung.com/java-9-compact-string)
-- [Convert Date to LocalDate or LocalDateTime and Back](http://www.baeldung.com/java-date-to-localdate-and-localdatetime)
 - [Java 9 Variable Handles Demistyfied](http://www.baeldung.com/java-variable-handles)
 - [Exploring the New HTTP Client in Java 9](http://www.baeldung.com/java-9-http-client)
 - [Method Handles in Java](http://www.baeldung.com/java-method-handles)
@@ -26,3 +23,4 @@
 - [A Guide to Java 9 Modularity](http://www.baeldung.com/java-9-modularity)
 - [Optional orElse Optional](http://www.baeldung.com/java-optional-or-else-optional)
 - [Java 9 java.lang.Module API](http://www.baeldung.com/java-9-module-api)
+- [Iterate Through a Range of Dates in Java](https://www.baeldung.com/java-iterate-date-range)

core-java-9/src/main/java/com/baeldung/java9/rangedates/DatesCollectionIteration.java

@@ -0,0 +1,24 @@
+package com.baeldung.java9.rangedates;
+
+import java.util.Collection;
+import java.util.Date;
+
+public class DatesCollectionIteration {
+
+    public void iteratingRangeOfDatesJava7(Collection<Date> dates) {
+
+        for (Date date : dates) {
+            processDate(date);
+        }
+    }
+
+    public void iteratingRangeOfDatesJava8(Collection<Date> dates) {
+        dates.stream()
+            .forEach(this::processDate);
+    }
+
+    private void processDate(Date date) {
+        System.out.println(date);
+    }
+
+}

core-java-9/src/main/java/com/baeldung/java9/rangedates/RangeDatesIteration.java

@@ -0,0 +1,43 @@
+package com.baeldung.java9.rangedates;
+
+import java.time.LocalDate;
+import java.util.Calendar;
+import java.util.Date;
+
+public class RangeDatesIteration {
+
+    public void iterateBetweenDatesJava9(LocalDate startDate, LocalDate endDate) {
+
+        startDate.datesUntil(endDate)
+            .forEach(this::processDate);
+    }
+
+    public void iterateBetweenDatesJava8(LocalDate start, LocalDate end) {
+        for (LocalDate date = start; date.isBefore(end); date = date.plusDays(1)) {
+            processDate(date);
+        }
+    }
+
+    public void iterateBetweenDatesJava7(Date start, Date end) {
+        Date current = start;
+
+        while (current.before(end)) {
+            processDate(current);
+
+            Calendar calendar = Calendar.getInstance();
+            calendar.setTime(current);
+
+            calendar.add(Calendar.DATE, 1);
+
+            current = calendar.getTime();
+        }
+    }
+
+    private void processDate(LocalDate date) {
+        System.out.println(date);
+    }
+
+    private void processDate(Date date) {
+        System.out.println(date);
+    }
+}

core-java-9/src/main/resources/logback.xml

@@ -2,7 +2,7 @@
 <configuration>
     <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
         <encoder>
-            <pattern>web - %date [%thread] %-5level %logger{36} - %message%n
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
             </pattern>
         </encoder>
     </appender>

core-java-9/src/test/java/com/baeldung/java9/rangedates/DatesCollectionIterationUnitTest.java

@@ -0,0 +1,61 @@
+package com.baeldung.java9.rangedates;
+
+import java.time.LocalDate;
+import java.time.ZoneId;
+import java.time.temporal.ChronoUnit;
+import java.util.ArrayList;
+import java.util.Calendar;
+import java.util.Collection;
+import java.util.Date;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import org.junit.Test;
+
+public class DatesCollectionIterationUnitTest {
+
+    private Collection<LocalDate> localDates = LocalDate.now()
+        .datesUntil(LocalDate.now()
+            .plus(10L, ChronoUnit.DAYS))
+        .collect(Collectors.toList());
+
+    private Collection<Date> dates = localDates.stream()
+        .map(localDate -> Date.from(localDate.atStartOfDay(ZoneId.systemDefault())
+            .toInstant()))
+        .collect(Collectors.toList());
+
+    @Test
+    public void givenIteratingListOfDatesJava7_WhenStartTodayAndEnding10DaysAhead() {
+        DatesCollectionIteration iterateInColleciton = new DatesCollectionIteration();
+        Calendar today = Calendar.getInstance();
+        Calendar next10Ahead = (Calendar) today.clone();
+        next10Ahead.add(Calendar.DATE, 10);
+
+        iterateInColleciton.iteratingRangeOfDatesJava7(createRangeDates(today.getTime(), next10Ahead.getTime()));
+    }
+
+    @Test
+    public void givenIteratingListOfDatesJava8_WhenStartTodayAndEnd10DaysAhead() {
+        DatesCollectionIteration iterateInColleciton = new DatesCollectionIteration();
+
+        iterateInColleciton.iteratingRangeOfDatesJava8(dates);
+    }
+
+    private List<Date> createRangeDates(Date start, Date end) {
+
+        List<Date> dates = new ArrayList<>();
+        Date current = start;
+
+        while (current.before(end)) {
+            dates.add(current);
+            
+            Calendar calendar = Calendar.getInstance();
+            calendar.setTime(current);
+            calendar.add(Calendar.DATE, 1);
+
+            current = calendar.getTime();
+        }
+
+        return dates;
+    }
+}

core-java-9/src/test/java/com/baeldung/java9/rangedates/RangeDatesIterationUnitTest.java

@@ -0,0 +1,48 @@
+package com.baeldung.java9.rangedates;
+
+import java.time.LocalDate;
+import java.time.temporal.ChronoUnit;
+import java.util.Calendar;
+import java.util.Date;
+
+import org.junit.Test;
+
+public class RangeDatesIterationUnitTest {
+
+    @Test
+    public void givenIterateBetweenDatesJava9_WhenStartDateAsTodayAndEndDateAs10DaysAhead() {
+        LocalDate start = LocalDate.now();
+        LocalDate end = start.plus(10L, ChronoUnit.DAYS);
+
+        RangeDatesIteration iteration = new RangeDatesIteration();
+
+        iteration.iterateBetweenDatesJava9(start, end);
+    }
+
+    @Test
+    public void givenIterateBetweenDatesJava8_WhenStartDateAsTodayAndEndDateAs10DaysAhead() {
+        LocalDate start = LocalDate.now();
+        LocalDate end = start.plus(10L, ChronoUnit.DAYS);
+
+        RangeDatesIteration iteration = new RangeDatesIteration();
+
+        iteration.iterateBetweenDatesJava8(start, end);
+    }
+
+    @Test
+    public void givenIterateBetweenDatesJava7_WhenStartDateAsTodayAndEndDateAs10DaysAhead() {
+        Calendar today = Calendar.getInstance();
+        Calendar calendar = Calendar.getInstance();
+        calendar.clear();
+        calendar.set(today.get(Calendar.YEAR), today.get(Calendar.MONTH), today.get(Calendar.DATE));
+        Date start = calendar.getTime();
+
+        calendar.add(Calendar.DATE, 10);
+        Date end = calendar.getTime();
+
+        RangeDatesIteration iteration = new RangeDatesIteration();
+
+        iteration.iterateBetweenDatesJava7(start, end);
+    }
+
+}

core-java-collections/README.md

@@ -36,3 +36,4 @@
 - [Remove the First Element from a List](http://www.baeldung.com/java-remove-first-element-from-list)
 - [How to Convert List to Map in Java](http://www.baeldung.com/java-list-to-map)
 - [Initializing HashSet at the Time of Construction](http://www.baeldung.com/java-initialize-hashset)
+- [Removing the First Element of an Array](https://www.baeldung.com/java-array-remove-first-element)

core-java-collections/pom.xml

@@ -53,15 +53,27 @@
             <version>${junit.platform.version}</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-core</artifactId>
+            <version>${openjdk.jmh.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-generator-annprocess</artifactId>
+            <version>${openjdk.jmh.version}</version>
+        </dependency>
     </dependencies>
 
+
     <properties>
+        <openjdk.jmh.version>1.19</openjdk.jmh.version>
         <junit.platform.version>1.2.0</junit.platform.version>
         <commons-lang3.version>3.5</commons-lang3.version>
         <commons-collections4.version>4.1</commons-collections4.version>
         <collections-generic.version>4.01</collections-generic.version>
         <avaitility.version>1.7.0</avaitility.version>
         <assertj.version>3.6.1</assertj.version>
-        <eclipse.collections.version>9.2.0</eclipse.collections.version>
+        <eclipse.collections.version>7.1.0</eclipse.collections.version>
     </properties>
 </project>

core-java-collections/src/main/java/com/baeldung/performance/CollectionsBenchmark.java

@@ -0,0 +1,59 @@
+package com.baeldung.performance;
+
+import org.openjdk.jmh.annotations.*;
+import org.openjdk.jmh.runner.Runner;
+import org.openjdk.jmh.runner.options.Options;
+import org.openjdk.jmh.runner.options.OptionsBuilder;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.concurrent.TimeUnit;
+
+@BenchmarkMode(Mode.AverageTime)
+@OutputTimeUnit(TimeUnit.NANOSECONDS)
+@Warmup(iterations = 5)
+public class CollectionsBenchmark {
+
+    @State(Scope.Thread)
+    public static class MyState {
+        private Set<Employee> employeeSet = new HashSet<>();
+        private List<Employee> employeeList = new ArrayList<>();
+
+        private long iterations = 10000;
+
+        private Employee employee = new Employee(100L, "Harry");
+
+        @Setup(Level.Trial)
+        public void setUp() {
+
+            for (long i = 0; i < iterations; i++) {
+                employeeSet.add(new Employee(i, "John"));
+                employeeList.add(new Employee(i, "John"));
+            }
+
+            employeeList.add(employee);
+            employeeSet.add(employee);
+        }
+    }
+
+    @Benchmark
+    public boolean testArrayList(MyState state) {
+        return state.employeeList.contains(state.employee);
+    }
+
+    @Benchmark
+    public boolean testHashSet(MyState state) {
+        return state.employeeSet.contains(state.employee);
+    }
+
+    public static void main(String[] args) throws Exception {
+        Options options = new OptionsBuilder()
+                .include(CollectionsBenchmark.class.getSimpleName()).threads(1)
+                .forks(1).shouldFailOnError(true)
+                .shouldDoGC(true)
+                .jvmArgs("-server").build();
+        new Runner(options).run();
+    }
+}

core-java-collections/src/main/java/com/baeldung/performance/Employee.java

@@ -0,0 +1,31 @@
+package com.baeldung.performance;
+
+public class Employee {
+
+    private Long id;
+    private String name;
+
+    public Employee(Long id, String name) {
+        this.name = name;
+        this.id = id;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+
+        Employee employee = (Employee) o;
+
+        if (!id.equals(employee.id)) return false;
+        return name.equals(employee.name);
+
+    }
+
+    @Override
+    public int hashCode() {
+        int result = id.hashCode();
+        result = 31 * result + name.hashCode();
+        return result;
+    }
+}

core-java-collections/src/test/java/com/baeldung/collection/StreamOperateAndRemoveUnitTest.java

@@ -0,0 +1,80 @@
+package com.baeldung.collection;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.function.Predicate;
+import java.util.stream.Collectors;
+
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class StreamOperateAndRemoveUnitTest {
+
+    private List<Item> itemList;
+
+    @Before
+    public void setup() {
+
+        itemList = new ArrayList<>();
+        for (int i = 0; i < 10; i++) {
+            itemList.add(new Item(i));
+        }
+    }
+
+    @Test
+    public void givenAListOf10Items_whenFilteredForQualifiedItems_thenFilteredListContains5Items() {
+
+        final List<Item> filteredList = itemList.stream().filter(item -> item.isQualified())
+            .collect(Collectors.toList());
+
+        Assert.assertEquals(5, filteredList.size());
+    }
+
+    @Test
+    public void givenAListOf10Items_whenOperateAndRemoveQualifiedItemsUsingRemoveIf_thenListContains5Items() {
+
+        final Predicate<Item> isQualified = item -> item.isQualified();
+        itemList.stream().filter(isQualified).forEach(item -> item.operate());
+        itemList.removeIf(isQualified);
+
+        Assert.assertEquals(5, itemList.size());
+    }
+
+    @Test
+    public void givenAListOf10Items_whenOperateAndRemoveQualifiedItemsUsingRemoveAll_thenListContains5Items() {
+
+        final List<Item> operatedList = new ArrayList<>();
+        itemList.stream().filter(item -> item.isQualified()).forEach(item -> {
+            item.operate();
+            operatedList.add(item);
+        });
+        itemList.removeAll(operatedList);
+
+        Assert.assertEquals(5, itemList.size());
+    }
+
+    class Item {
+
+        private final Logger logger = LoggerFactory.getLogger(this.getClass().getName());
+
+        private final int value;
+
+        public Item(final int value) {
+
+            this.value = value;
+        }
+
+        public boolean isQualified() {
+
+            return value % 2 == 0;
+        }
+
+        public void operate() {
+
+            logger.info("Even Number: " + this.value);
+        }
+    }
+}

core-java-collections/src/test/java/com/baeldung/list/removefirst/RemoveFirstElementUnitTest.java

@@ -4,6 +4,7 @@ import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.*;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.LinkedList;
 import java.util.List;
 
@@ -48,4 +49,14 @@ public class RemoveFirstElementUnitTest {
         assertThat(linkedList, not(contains("cat")));
     }
 
+    @Test
+    public void givenStringArray_whenRemovingFirstElement_thenArrayIsSmallerAndElementRemoved() {
+        String[] stringArray = {"foo", "bar", "baz"};
+
+        String[] modifiedArray = Arrays.copyOfRange(stringArray, 1, stringArray.length);
+
+        assertThat(modifiedArray.length, is(2));
+        assertThat(modifiedArray[0], is("bar"));
+    }
+
 }

core-java-collections/src/test/java/org/baeldung/java/collections/CollectionsEmpty.java

@@ -0,0 +1,26 @@
+package org.baeldung.java.collections;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import org.junit.Assert;
+import org.junit.Test;
+
+class CollectionsEmpty {
+
+    @Test
+    public void givenArrayList_whenAddingElement_addsNewElement() {
+        ArrayList<String> mutableList = new ArrayList<>();
+        mutableList.add("test");
+
+        Assert.assertEquals(mutableList.size(), 1);
+        Assert.assertEquals(mutableList.get(0), "test");
+    }
+
+    @Test(expected = UnsupportedOperationException.class)
+    public void givenCollectionsEmptyList_whenAddingElement_throwsUnsupportedOperationException() {
+        List<String> immutableList = Collections.emptyList();
+        immutableList.add("test");
+    }
+
+}

core-java-concurrency-collections/.gitignore

@@ -0,0 +1,26 @@
+*.class
+
+0.*
+
+#folders#
+/target
+/neoDb*
+/data
+/src/main/webapp/WEB-INF/classes
+*/META-INF/*
+.resourceCache
+
+# Packaged files #
+*.jar
+*.war
+*.ear
+
+# Files generated by integration tests
+*.txt
+backup-pom.xml
+/bin/
+/temp
+
+#IntelliJ specific
+.idea/
+*.iml

core-java-concurrency-collections/README.md

@@ -0,0 +1,15 @@
+=========
+
+## Core Java Concurrency Collections Examples
+
+### Relevant Articles: 
+- [Guide to java.util.concurrent.BlockingQueue](http://www.baeldung.com/java-blocking-queue)
+- [A Guide to ConcurrentMap](http://www.baeldung.com/java-concurrent-map)
+- [Guide to PriorityBlockingQueue in Java](http://www.baeldung.com/java-priority-blocking-queue)
+- [Avoiding the ConcurrentModificationException in Java](http://www.baeldung.com/java-concurrentmodificationexception)
+- [Custom Thread Pools In Java 8 Parallel Streams](http://www.baeldung.com/java-8-parallel-streams-custom-threadpool)
+- [Guide to DelayQueue](http://www.baeldung.com/java-delay-queue)
+- [A Guide to Java SynchronousQueue](http://www.baeldung.com/java-synchronous-queue)
+- [Guide to the Java TransferQueue](http://www.baeldung.com/java-transfer-queue)
+- [Guide to the ConcurrentSkipListMap](http://www.baeldung.com/java-concurrent-skip-list-map)
+- [Guide to CopyOnWriteArrayList](http://www.baeldung.com/java-copy-on-write-arraylist)

core-java-concurrency-collections/pom.xml

@@ -0,0 +1,94 @@
+<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-java-concurrency-collections</artifactId>
+    <version>0.1.0-SNAPSHOT</version>
+    <packaging>jar</packaging>
+    <name>core-java-concurrency-collections</name>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-java</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../parent-java</relativePath>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-collections4</artifactId>
+            <version>${commons-collections4.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>commons-io</groupId>
+            <artifactId>commons-io</artifactId>
+            <version>${commons-io.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-lang3</artifactId>
+            <version>${commons-lang3.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-math3</artifactId>
+            <version>${commons-math3.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>com.jayway.awaitility</groupId>
+            <artifactId>awaitility</artifactId>
+            <version>${avaitility.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <finalName>core-java-concurrency-collections</finalName>
+        <resources>
+            <resource>
+                <directory>src/main/resources</directory>
+                <filtering>true</filtering>
+            </resource>
+        </resources>
+
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-dependency-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <id>copy-dependencies</id>
+                        <phase>prepare-package</phase>
+                        <goals>
+                            <goal>copy-dependencies</goal>
+                        </goals>
+                        <configuration>
+                            <outputDirectory>${project.build.directory}/libs</outputDirectory>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+            
+        </plugins>
+    </build>
+
+    <properties>
+        <!-- util -->
+        <guava.version>21.0</guava.version>
+        <commons-lang3.version>3.5</commons-lang3.version>
+        <commons-math3.version>3.6.1</commons-math3.version>
+        <commons-collections4.version>4.1</commons-collections4.version>
+        <collections-generic.version>4.01</collections-generic.version>
+        <!-- testing -->
+        <assertj.version>3.6.1</assertj.version>
+        <avaitility.version>1.7.0</avaitility.version>
+    </properties>
+
+</project>

core-java-concurrency-collections/src/main/java/com/baeldung/concurrent/blockingqueue/BlockingQueueUsage.java

@@ -10,15 +10,18 @@ public class BlockingQueueUsage {
         int N_CONSUMERS = Runtime.getRuntime().availableProcessors();
         int poisonPill = Integer.MAX_VALUE;
         int poisonPillPerProducer = N_CONSUMERS / N_PRODUCERS;
-
+        int mod = N_CONSUMERS % N_PRODUCERS;
         BlockingQueue<Integer> queue = new LinkedBlockingQueue<>(BOUND);
 
-        for (int i = 0; i < N_PRODUCERS; i++) {
+        for (int i = 1; i < N_PRODUCERS; i++) {
             new Thread(new NumbersProducer(queue, poisonPill, poisonPillPerProducer)).start();
         }
 
         for (int j = 0; j < N_CONSUMERS; j++) {
             new Thread(new NumbersConsumer(queue, poisonPill)).start();
         }
+        
+        new Thread(new NumbersProducer(queue, poisonPill, poisonPillPerProducer+mod)).start();
+
     }
 }

core-java-concurrency-collections/src/main/resources/logback.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>web - %date [%thread] %-5level %logger{36} - %message%n
+            </pattern>
+        </encoder>
+    </appender>
+
+    <logger name="org.springframework" level="WARN" />
+    <logger name="org.springframework.transaction" level="WARN" />
+
+    <!-- in order to debug some marshalling issues, this needs to be TRACE -->
+    <logger name="org.springframework.web.servlet.mvc" level="WARN" />
+
+    <root level="INFO">
+        <appender-ref ref="STDOUT" />
+    </root>
+</configuration>

core-java-concurrency/README.md

@@ -7,22 +7,12 @@
 - [A Guide to the Java ExecutorService](http://www.baeldung.com/java-executor-service-tutorial)
 - [Introduction to Thread Pools in Java](http://www.baeldung.com/thread-pool-java-and-guava)
 - [Guide to java.util.concurrent.Future](http://www.baeldung.com/java-future)
-- [Guide to java.util.concurrent.BlockingQueue](http://www.baeldung.com/java-blocking-queue)
 - [Guide to CountDownLatch in Java](http://www.baeldung.com/java-countdown-latch)
-- [A Guide to ConcurrentMap](http://www.baeldung.com/java-concurrent-map)
-- [Guide to PriorityBlockingQueue in Java](http://www.baeldung.com/java-priority-blocking-queue)
-- [Avoiding the ConcurrentModificationException in Java](http://www.baeldung.com/java-concurrentmodificationexception)
-- [Custom Thread Pools In Java 8 Parallel Streams](http://www.baeldung.com/java-8-parallel-streams-custom-threadpool)
 - [Guide to java.util.concurrent.Locks](http://www.baeldung.com/java-concurrent-locks)
 - [An Introduction to ThreadLocal in Java](http://www.baeldung.com/java-threadlocal)
-- [Guide to DelayQueue](http://www.baeldung.com/java-delay-queue)
-- [A Guide to Java SynchronousQueue](http://www.baeldung.com/java-synchronous-queue)
-- [Guide to the Java TransferQueue](http://www.baeldung.com/java-transfer-queue)
-- [Guide to the ConcurrentSkipListMap](http://www.baeldung.com/java-concurrent-skip-list-map)
 - [Difference Between Wait and Sleep in Java](http://www.baeldung.com/java-wait-and-sleep)
 - [LongAdder and LongAccumulator in Java](http://www.baeldung.com/java-longadder-and-longaccumulator)
 - [The Dining Philosophers Problem in Java](http://www.baeldung.com/java-dining-philoshophers)
-- [Guide to CopyOnWriteArrayList](http://www.baeldung.com/java-copy-on-write-arraylist)
 - [Guide to the Java Phaser](http://www.baeldung.com/java-phaser)
 - [Guide to Synchronized Keyword in Java](http://www.baeldung.com/java-synchronized)
 - [An Introduction to Atomic Variables in Java](http://www.baeldung.com/java-atomic-variables)

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

@@ -2,7 +2,7 @@
 <configuration>
     <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
         <encoder>
-            <pattern>web - %date [%thread] %-5level %logger{36} - %message%n
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
             </pattern>
         </encoder>
     </appender>

core-java-io/pom.xml

@@ -183,6 +183,7 @@
             <plugin>
                 <groupId>org.springframework.boot</groupId>
                 <artifactId>spring-boot-maven-plugin</artifactId>
+                <version>${spring-boot-maven-plugin.version}</version>
                 <executions>
                     <execution>
                         <goals>
@@ -316,6 +317,7 @@
         <esapi.version>2.1.0.1</esapi.version>
         <jmh-generator-annprocess.version>1.19</jmh-generator-annprocess.version>
         <async-http-client.version>2.4.5</async-http-client.version>
+        <spring-boot-maven-plugin.version>2.0.4.RELEASE</spring-boot-maven-plugin.version>
     </properties>
 
 </project>

core-java-io/src/main/java/com/baeldung/fileparser/BufferedReaderExample.java

@@ -0,0 +1,24 @@
+package com.baeldung.fileparser;
+
+import java.io.BufferedReader;
+import java.io.FileReader;
+import java.io.IOException;
+import java.util.ArrayList;
+
+public class BufferedReaderExample {
+
+    protected static ArrayList<String> generateArrayListFromFile(String filename) throws IOException {
+
+        ArrayList<String> result = new ArrayList<>();
+
+        try (BufferedReader br = new BufferedReader(new FileReader(filename))) {
+
+            while (br.ready()) {
+                result.add(br.readLine());
+            }
+            return result;
+        }
+
+    }
+
+}

core-java-io/src/main/java/com/baeldung/fileparser/FileReaderExample.java

@@ -0,0 +1,31 @@
+package com.baeldung.fileparser;
+
+import java.io.FileReader;
+import java.io.IOException;
+import java.util.ArrayList;
+
+public class FileReaderExample {
+
+    protected static ArrayList<String> generateArrayListFromFile(String filename) throws IOException {
+
+        ArrayList<String> result = new ArrayList<>();
+
+        try (FileReader f = new FileReader(filename)) {
+            StringBuffer sb = new StringBuffer();
+            while (f.ready()) {
+                char c = (char) f.read();
+                if (c == '\n') {
+                    result.add(sb.toString());
+                    sb = new StringBuffer();
+                } else {
+                    sb.append(c);
+                }
+            }
+            if (sb.length() > 0) {
+                result.add(sb.toString());
+            }
+        }
+        
+        return result;
+    }
+}

core-java-io/src/main/java/com/baeldung/fileparser/FilesReadLinesExample.java

@@ -0,0 +1,18 @@
+package com.baeldung.fileparser;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.util.ArrayList;
+import java.util.List;
+
+public class FilesReadLinesExample {
+
+    protected static ArrayList<String> generateArrayListFromFile(String filename) throws IOException {
+        
+        List<String> result = Files.readAllLines(Paths.get(filename));
+        
+        return (ArrayList<String>) result;
+    }
+
+}

core-java-io/src/main/java/com/baeldung/fileparser/ScannerIntExample.java

@@ -0,0 +1,24 @@
+package com.baeldung.fileparser;
+
+import java.io.FileReader;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Scanner;
+
+public class ScannerIntExample {
+
+    protected static ArrayList<Integer> generateArrayListFromFile(String filename) throws IOException {
+        
+        ArrayList<Integer> result = new ArrayList<>();
+
+        try (Scanner s = new Scanner(new FileReader(filename))) {
+
+            while (s.hasNext()) {
+                result.add(s.nextInt());
+            }
+            return result;
+        }
+
+    }
+
+}

core-java-io/src/main/java/com/baeldung/fileparser/ScannerStringExample.java

@@ -0,0 +1,24 @@
+package com.baeldung.fileparser;
+
+import java.io.FileReader;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Scanner;
+
+public class ScannerStringExample {
+
+    protected static ArrayList<String> generateArrayListFromFile(String filename) throws IOException {
+        
+        ArrayList<String> result = new ArrayList<>();
+
+        try (Scanner s = new Scanner(new FileReader(filename))) {
+
+            while (s.hasNext()) {
+                result.add(s.nextLine());
+            }
+            return result;
+        }
+
+    }
+
+}

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

@@ -2,7 +2,7 @@
 <configuration>
     <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
         <encoder>
-            <pattern>web - %date [%thread] %-5level %logger{36} - %message%n
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
             </pattern>
         </encoder>
     </appender>

core-java-io/src/test/java/com/baeldung/file/FilenameFilterManualTest.java

@@ -18,7 +18,7 @@ public class FilenameFilterManualTest {
     @BeforeClass
     public static void setupClass() {
         directory = new File(FilenameFilterManualTest.class.getClassLoader()
-            .getResource("testFolder")
+            .getResource("fileNameFilterManualTestFolder")
             .getFile());
     }
 

core-java-io/src/test/java/com/baeldung/fileparser/BufferedReaderUnitTest.java

@@ -0,0 +1,19 @@
+package com.baeldung.fileparser;
+
+import static org.junit.Assert.assertTrue;
+
+import java.io.IOException;
+import java.util.List;
+
+import org.junit.Test;
+
+public class BufferedReaderUnitTest {
+
+    protected static final String TEXT_FILENAME = "src/test/resources/sampleTextFile.txt";
+    
+    @Test
+    public void whenParsingExistingTextFile_thenGetArrayList() throws IOException {
+        List<String> lines = BufferedReaderExample.generateArrayListFromFile(TEXT_FILENAME);
+        assertTrue("File does not has 2 lines", lines.size() == 2);
+    }
+}

core-java-io/src/test/java/com/baeldung/fileparser/FileReaderUnitTest.java

@@ -0,0 +1,19 @@
+package com.baeldung.fileparser;
+
+import static org.junit.Assert.assertTrue;
+
+import java.io.IOException;
+import java.util.List;
+
+import org.junit.Test;
+
+public class FileReaderUnitTest {
+
+    protected static final String TEXT_FILENAME = "src/test/resources/sampleTextFile.txt";
+    
+    @Test
+    public void whenParsingExistingTextFile_thenGetArrayList() throws IOException {
+        List<String> lines = FileReaderExample.generateArrayListFromFile(TEXT_FILENAME);
+        assertTrue("File does not has 2 lines", lines.size() == 2);
+    }
+}