Merge branch 'master' of https://github.com/eugenp/tutorials

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));
+    }
+
+}

core-java-8/README.md

@@ -9,15 +9,10 @@
 - [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)
 - [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)
@@ -27,15 +22,10 @@
 - [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)
-- [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)
 - [Introduction to Spliterator in Java](http://www.baeldung.com/java-spliterator)

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>
@@ -177,7 +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>

core-java/src/main/java/com/baeldung/classcastexception/ClassCastException.java

@@ -0,0 +1,21 @@
+package com.baeldung.classcastexception;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+public class ClassCastException {
+
+	public static void main(String[] args) {
+
+		String p1 = new String("John");
+		String p2 = new String("Snow");
+		String[] strArray = new String[] { p1, p2 };
+		ArrayList<String> strList = (ArrayList<String>) Arrays.asList(strArray);
+		// To fix the ClassCastException at above line, modify the code as:
+		// List<String> strList = Arrays.asList(strArray);
+		System.out.println("String list: " + strList);
+
+	}
+
+}

core-java/src/main/java/com/baeldung/throwsexception/PersonRepository.java

@@ -8,7 +8,7 @@ public class PersonRepository {
 
     @Nullable
     public String findNameById(String id) {
-        return id == null ? null : "example-name";
+        return id == null ? null : "Name";
     }
 
     public List<String> findAll() throws SQLException {

core-java/src/test/java/com/baeldung/throwsexception/PersonRepositoryUnitTest.java

@@ -4,6 +4,7 @@ import org.junit.Test;
 
 import java.util.Optional;
 
+import static org.junit.Assert.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertAll;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
@@ -29,4 +30,14 @@ public class PersonRepositoryUnitTest {
                                 .orElseThrow(Exception::new));
     }
 
+    @Test
+    public void whenIdIsNonNull_thenShouldReturnNameUpperCase() throws Exception {
+        String name = Optional
+                .ofNullable(personRepository.findNameById("id"))
+                .map(String::toUpperCase)
+                .orElseThrow(Exception::new);
+
+        assertEquals("NAME", name);
+    }
+
 }

java-streams/.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

java-streams/README.md

@@ -0,0 +1,14 @@
+=========
+
+## Java Streams Cookbooks and Examples
+
+### Relevant Articles: 
+- [Java 8 Streams Advanced](http://www.baeldung.com/java-8-streams)
+- [Introduction to Java 8 Streams](http://www.baeldung.com/java-8-streams-introduction)
+- [Java 8 and Infinite Streams](http://www.baeldung.com/java-inifinite-streams)
+- [Java 8 Stream findFirst() vs. findAny()](http://www.baeldung.com/java-stream-findfirst-vs-findany)
+- [How to Get the Last Element of a Stream in Java?](http://www.baeldung.com/java-stream-last-element)
+- [”Stream has already been operated upon or closed” Exception in Java](http://www.baeldung.com/java-stream-operated-upon-or-closed-exception)
+- [Iterable to Stream in Java](http://www.baeldung.com/java-iterable-to-stream)
+- [How to Iterate Over a Stream With Indices](http://www.baeldung.com/java-stream-indices)
+- [Primitive Type Streams in Java 8](http://www.baeldung.com/java-8-primitive-streams)

java-streams/pom.xml

@@ -0,0 +1,120 @@
+<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>java-streams</artifactId>
+    <version>0.1.0-SNAPSHOT</version>
+    <packaging>jar</packaging>
+    <name>java-streams</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-lang3</artifactId>
+            <version>${commons-lang3.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>log4j</groupId>
+            <artifactId>log4j</artifactId>
+            <version>${log4j.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <version>${lombok.version}</version>
+            <scope>provided</scope>
+        </dependency>
+        <!-- test scoped -->
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>com.codepoetics</groupId>
+            <artifactId>protonpack</artifactId>
+            <version>${protonpack.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>io.vavr</groupId>
+            <artifactId>vavr</artifactId>
+            <version>${vavr.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>one.util</groupId>
+            <artifactId>streamex</artifactId>
+            <version>${streamex.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.aspectj</groupId>
+            <artifactId>aspectjrt</artifactId>
+            <version>${asspectj.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.aspectj</groupId>
+            <artifactId>aspectjweaver</artifactId>
+            <version>${asspectj.version}</version>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <finalName>java-streams</finalName>
+        <resources>
+            <resource>
+                <directory>src/main/resources</directory>
+                <filtering>true</filtering>
+            </resource>
+        </resources>
+
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-dependency-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <id>copy-dependencies</id>
+                        <phase>prepare-package</phase>
+                        <goals>
+                            <goal>copy-dependencies</goal>
+                        </goals>
+                        <configuration>
+                            <outputDirectory>${project.build.directory}/libs</outputDirectory>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>3.1</version>
+                <configuration>
+                    <source>1.8</source>
+                    <target>1.8</target>
+                    <compilerArgument>-parameters</compilerArgument>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+    <properties>
+        <!-- util -->
+        <commons-lang3.version>3.5</commons-lang3.version>
+        <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>
+        <asspectj.version>1.8.9</asspectj.version>
+    </properties>
+</project>

java-streams/src/main/resources/logback.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
+            </pattern>
+        </encoder>
+    </appender>
+
+    <root level="INFO">
+        <appender-ref ref="STDOUT" />
+    </root>
+</configuration>

java-streams/src/test/resources/.gitignore

@@ -0,0 +1,13 @@
+*.class
+
+#folders#
+/target
+/neoDb*
+/data
+/src/main/webapp/WEB-INF/classes
+*/META-INF/*
+
+# Packaged files #
+*.jar
+*.war
+*.ear

pom.xml

@@ -348,6 +348,7 @@
 				<module>core-java-collections</module>
 				<module>core-java-io</module>
 				<module>core-java-8</module>
+				<module>java-streams</module>
                 <module>core-java-persistence</module>
 				<module>core-kotlin</module>
 				<module>core-groovy</module>
@@ -902,6 +903,7 @@
 				<module>core-java-collections</module>
 				<module>core-java-io</module>
 				<module>core-java-8</module>
+				<module>java-streams</module>
 				<module>core-groovy</module>
 
 				<module>couchbase</module>

testing-modules/streams-ordering/pom.xml

@@ -0,0 +1,34 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<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>StreamsOrdering</artifactId>
+    <version>1.0-SNAPSHOT</version>
+
+    <dependencies>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.12</version>
+            <scope>test</scope>
+
+        </dependency>
+        <!-- https://mvnrepository.com/artifact/org.openjdk.jmh/jmh-core -->
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-core</artifactId>
+            <version>1.21</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-generator-annprocess</artifactId>
+            <version>1.21</version>
+            <scope>provided</scope>
+        </dependency>
+
+    </dependencies>
+</project>

testing-modules/streams-ordering/src/test/java/StreamsOrderingTest.java

@@ -0,0 +1,148 @@
+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 StreamsOrderingTest {
+
+  Logger logger = Logger.getLogger( StreamsOrderingTest.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));
+  }
+
+}

testing-modules/streams-ordering/src/test/java/benchmarking/TestBenchmark.java

@@ -0,0 +1,97 @@
+package benchmarking;
+
+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 TestBenchmark
+{
+
+  @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));
+  }
+}