Merge remote-tracking branch 'upstream/master'

2017-04-11 22:40:55 -06:00
parent 8f1ca08b46 d21d7a1e2e
commit ee7724345e
1462 changed files with 67531 additions and 4384 deletions
@@ -1,3 +1,5 @@
+*/bin/*
+
 *.class

 # Package Files #
@@ -1,11 +1,13 @@
 language: java

-install: travis_wait 40 mvn -q clean install -Dgib.enabled=true
+install: travis_wait 60 mvn -q test
+
+before_script:
+  - echo "MAVEN_OPTS='-Xmx2048M -Xss128M -XX:MaxPermSize=2048M -XX:+CMSClassUnloadingEnabled -XX:+UseConcMarkSweepGC -XX:+TieredCompilation -XX:TieredStopAtLevel=1 -XX:-UseGCOverheadLimit'" > ~/.mavenrc

 jdk:
  - oraclejdk8

-sudo: false
 addons:
  apt:
    packages:
@@ -14,4 +16,6 @@ addons:
 cache:
  directories:
  - .autoconf
-  - $HOME/.m2
+  - $HOME/.m2
+  
+
@@ -0,0 +1,3 @@
+### Relevant articles
+
+- [Introduction to Twitter4J](http://www.baeldung.com/twitter4j)
@@ -0,0 +1,53 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>com.mabsisa</groupId>
+  <artifactId>Twitter4J</artifactId>
+  <packaging>jar</packaging>
+  <version>1.0-SNAPSHOT</version>
+  <name>Twitter4J</name>
+  <url>http://maven.apache.org</url>
+    
+	<properties>
+	    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+	    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
+	    <java.version>1.8</java.version>
+	    <maven.compiler.source>1.8</maven.compiler.source>
+		<maven.compiler.target>1.8</maven.compiler.target>
+	</properties>
+
+    <dependencies>
+		<dependency>
+    		<groupId>org.twitter4j</groupId>
+    		<artifactId>twitter4j-stream</artifactId>
+    		<version>4.0.6</version>
+		</dependency>
+		<dependency>
+		    <groupId>junit</groupId>
+		    <artifactId>junit</artifactId>
+		    <version>4.12</version>
+		</dependency>
+    </dependencies>
+    
+    <build>
+	    <finalName>${project.artifactId}</finalName>
+	    <resources>
+      		<resource>
+			<directory>src/main/resources</directory>
+      		</resource>
+	    </resources>
+	    <plugins>
+      		<plugin>
+        		<groupId>org.apache.maven.plugins</groupId>
+        		<artifactId>maven-surefire-plugin</artifactId>
+        		<version>2.19.1</version>
+        		<configuration>
+          			<excludes>
+            			<exclude>**/ApplicationTest.java</exclude>
+          			</excludes>
+        		</configuration>
+      		</plugin>
+    	</plugins>
+	</build>
+
+</project>
@@ -0,0 +1,116 @@
+/**
+ * 
+ */
+package com.baeldung;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+import twitter4j.DirectMessage;
+import twitter4j.Query;
+import twitter4j.QueryResult;
+import twitter4j.StallWarning;
+import twitter4j.Status;
+import twitter4j.StatusDeletionNotice;
+import twitter4j.StatusListener;
+import twitter4j.Twitter;
+import twitter4j.TwitterException;
+import twitter4j.TwitterFactory;
+import twitter4j.TwitterStream;
+import twitter4j.TwitterStreamFactory;
+import twitter4j.conf.ConfigurationBuilder;
+
+public class Application {
+
+	public static Twitter getTwitterinstance() {
+		/**
+		 * if not using properties file, we can set access token by following way
+		 */
+//		ConfigurationBuilder cb = new ConfigurationBuilder();
+//		cb.setDebugEnabled(true)
+//		  .setOAuthConsumerKey("//TODO")
+//		  .setOAuthConsumerSecret("//TODO")
+//		  .setOAuthAccessToken("//TODO")
+//		  .setOAuthAccessTokenSecret("//TODO");
+//		TwitterFactory tf = new TwitterFactory(cb.build());
+//		Twitter twitter = tf.getSingleton();
+		
+		Twitter twitter = TwitterFactory.getSingleton();
+		return twitter;
+		
+	}
+	
+	public static String createTweet(String tweet) throws TwitterException {
+		Twitter twitter = getTwitterinstance();
+		Status status = twitter.updateStatus("creating baeldung API");
+	        return status.getText();
+	}
+	
+	public static List<String> getTimeLine() throws TwitterException {
+		Twitter twitter = getTwitterinstance();
+		List<Status> statuses = twitter.getHomeTimeline();
+		return statuses.stream().map(
+				item -> item.getText()).collect(
+						Collectors.toList());
+	}
+	
+	public static String sendDirectMessage(String recipientName, String msg) throws TwitterException {
+		Twitter twitter = getTwitterinstance();
+	        DirectMessage message = twitter.sendDirectMessage(recipientName, msg);
+	        return message.getText();
+	}
+	
+	public static List<String> searchtweets() throws TwitterException {
+		Twitter twitter = getTwitterinstance();
+	        Query query = new Query("source:twitter4j baeldung");
+	        QueryResult result = twitter.search(query);
+	        List<Status> statuses = result.getTweets();
+	        return statuses.stream().map(
+				item -> item.getText()).collect(
+						Collectors.toList());
+	}
+	
+	public static void streamFeed() {
+		
+		StatusListener listener = new StatusListener(){
+
+			@Override
+			public void onException(Exception e) {
+				e.printStackTrace();
+			}
+
+			@Override
+			public void onDeletionNotice(StatusDeletionNotice arg) {
+                                System.out.println("Got a status deletion notice id:" + arg.getStatusId());
+			}
+
+			@Override
+			public void onScrubGeo(long userId, long upToStatusId) {
+                                System.out.println("Got scrub_geo event userId:" + userId + " upToStatusId:" + upToStatusId);
+			}
+
+			@Override
+			public void onStallWarning(StallWarning warning) {
+                                System.out.println("Got stall warning:" + warning);
+			}
+
+			@Override
+			public void onStatus(Status status) {
+                                System.out.println(status.getUser().getName() + " : " + status.getText());
+			}
+
+			@Override
+			public void onTrackLimitationNotice(int numberOfLimitedStatuses) {
+                                System.out.println("Got track limitation notice:" + numberOfLimitedStatuses);
+			}
+		};
+	
+		TwitterStream twitterStream = new TwitterStreamFactory().getInstance();
+		
+	        twitterStream.addListener(listener);
+	    
+	        twitterStream.sample();
+		
+	}
+	
+}
@@ -0,0 +1,4 @@
+oauth.consumerKey=//TODO
+oauth.consumerSecret=//TODO
+oauth.accessToken=//TODO
+oauth.accessTokenSecret=//TODO
@@ -0,0 +1,40 @@
+package com.baeldung;
+
+import static org.junit.Assert.assertEquals;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.junit.Test;
+
+import twitter4j.TwitterException;
+
+public class ApplicationTest {
+
+	/**
+	 * In order run this jUnit test you need to configure your API details in the twitter4j.properties
+	 */
+	
+	String tweet = "baeldung is awsome";
+	
+	@Test
+	public void givenText_updateStatus() throws TwitterException {
+		String text = Application.createTweet(tweet);
+		assertEquals(tweet, text);
+	}
+	
+	@Test
+	public void givenCredential_fetchStatus() throws TwitterException {
+		List<String> statuses = Application.getTimeLine();
+		List<String> expectedStatuses = new ArrayList<String>();
+		expectedStatuses.add(tweet);
+		assertEquals(expectedStatuses, statuses);
+	}
+	
+	@Test
+	public void givenRecipientNameAndMessage_sendDirectMessage() throws TwitterException {
+		String msg = Application.sendDirectMessage("YOUR_RECCIPIENT_ID", tweet);
+		assertEquals(msg, tweet);
+	}
+	
+}
@@ -0,0 +1 @@
+/target/
@@ -2,3 +2,6 @@

 - [Dijkstra Algorithm in Java](http://www.baeldung.com/java-dijkstra)
 - [Introduction to Cobertura](http://www.baeldung.com/cobertura)
+- [Ant Colony Optimization](http://www.baeldung.com/java-ant-colony-optimization)
+- [Validating Input With Finite Automata in Java](http://www.baeldung.com/finite-automata-java)
+- [Introduction to Jenetics Library](http://www.baeldung.com/jenetics)
@@ -9,15 +9,33 @@
 		<junit.version>4.12</junit.version>
 		<maven-compiler-plugin.version>3.6.0</maven-compiler-plugin.version>
 		<exec-maven-plugin.version>1.5.0</exec-maven-plugin.version>
+		<lombok.version>1.16.12</lombok.version>
+		<commons-math3.version>3.6.1</commons-math3.version>
 	</properties>

 	<dependencies>
+		<dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-math3</artifactId>
+            <version>${commons-math3.version}</version>
+        </dependency>
 		<dependency>
 			<groupId>junit</groupId>
 			<artifactId>junit</artifactId>
 			<version>${junit.version}</version>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <version>${lombok.version}</version>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+   	 		<groupId>io.jenetics</groupId>
+    		<artifactId>jenetics</artifactId>
+    		<version>3.7.0</version>
+		</dependency>
 	</dependencies>

 	<build>
@@ -9,13 +9,14 @@ import com.baeldung.algorithms.slope_one.SlopeOne;

 public class RunAlgorithm {

-	public static void main(String[] args) {
+	public static void main(String[] args) throws InstantiationException, IllegalAccessException {
 		Scanner in = new Scanner(System.in);
 		System.out.println("Run algorithm:");
 		System.out.println("1 - Simulated Annealing");
 		System.out.println("2 - Slope One");
 		System.out.println("3 - Simple Genetic Algorithm");
 		System.out.println("4 - Ant Colony");
+		System.out.println("5 - Dijkstra");
 		int decision = in.nextInt();
 		switch (decision) {
 		case 1:
@@ -33,6 +34,9 @@ public class RunAlgorithm {
 			AntColonyOptimization antColony = new AntColonyOptimization(21);
 			antColony.startAntOptimization();
 			break;
+		case 5:
+			System.out.println("Please run the DijkstraAlgorithmTest.");
+			break;
 		default:
 			System.out.println("Unknown option");
 			break;
@@ -0,0 +1,203 @@
+package com.baeldung.algorithms.ga.ant_colony;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.OptionalInt;
+import java.util.Random;
+import java.util.stream.IntStream;
+
+public class AntColonyOptimization {
+
+    private double c = 1.0;
+    private double alpha = 1;
+    private double beta = 5;
+    private double evaporation = 0.5;
+    private double Q = 500;
+    private double antFactor = 0.8;
+    private double randomFactor = 0.01;
+
+    private int maxIterations = 1000;
+
+    private int numberOfCities;
+    private int numberOfAnts;
+    private double graph[][];
+    private double trails[][];
+    private List<Ant> ants = new ArrayList<>();
+    private Random random = new Random();
+    private double probabilities[];
+
+    private int currentIndex;
+
+    private int[] bestTourOrder;
+    private double bestTourLength;
+
+    public AntColonyOptimization(int noOfCities) {
+        graph = generateRandomMatrix(noOfCities);
+        numberOfCities = graph.length;
+        numberOfAnts = (int) (numberOfCities * antFactor);
+
+        trails = new double[numberOfCities][numberOfCities];
+        probabilities = new double[numberOfCities];
+        IntStream.range(0, numberOfAnts)
+            .forEach(i -> ants.add(new Ant(numberOfCities)));
+    }
+
+    /**
+     * Generate initial solution
+     */
+    public double[][] generateRandomMatrix(int n) {
+        double[][] randomMatrix = new double[n][n];
+        IntStream.range(0, n)
+            .forEach(i -> IntStream.range(0, n)
+                .forEach(j -> randomMatrix[i][j] = Math.abs(random.nextInt(100) + 1)));
+        return randomMatrix;
+    }
+
+    /**
+     * Perform ant optimization
+     */
+    public void startAntOptimization() {
+        IntStream.rangeClosed(1, 3)
+            .forEach(i -> {
+                System.out.println("Attempt #" + i);
+                solve();
+            });
+    }
+
+    /**
+     * Use this method to run the main logic
+     */
+    public int[] solve() {
+        setupAnts();
+        clearTrails();
+        IntStream.range(0, maxIterations)
+            .forEach(i -> {
+                moveAnts();
+                updateTrails();
+                updateBest();
+            });
+        System.out.println("Best tour length: " + (bestTourLength - numberOfCities));
+        System.out.println("Best tour order: " + Arrays.toString(bestTourOrder));
+        return bestTourOrder.clone();
+    }
+
+    /**
+     * Prepare ants for the simulation
+     */
+    private void setupAnts() {
+        IntStream.range(0, numberOfAnts)
+            .forEach(i -> {
+                ants.forEach(ant -> {
+                    ant.clear();
+                    ant.visitCity(-1, random.nextInt(numberOfCities));
+                });
+            });
+        currentIndex = 0;
+    }
+
+    /**
+     * At each iteration, move ants
+     */
+    private void moveAnts() {
+        IntStream.range(currentIndex, numberOfCities - 1)
+            .forEach(i -> {
+                ants.forEach(ant -> ant.visitCity(currentIndex, selectNextCity(ant)));
+                currentIndex++;
+            });
+    }
+
+    /**
+     * Select next city for each ant
+     */
+    private int selectNextCity(Ant ant) {
+        int t = random.nextInt(numberOfCities - currentIndex);
+        if (random.nextDouble() < randomFactor) {
+            OptionalInt cityIndex = IntStream.range(0, numberOfCities)
+                .filter(i -> i == t && !ant.visited(i))
+                .findFirst();
+            if (cityIndex.isPresent()) {
+                return cityIndex.getAsInt();
+            }
+        }
+        calculateProbabilities(ant);
+        double r = random.nextDouble();
+        double total = 0;
+        for (int i = 0; i < numberOfCities; i++) {
+            total += probabilities[i];
+            if (total >= r) {
+                return i;
+            }
+        }
+
+        throw new RuntimeException("There are no other cities");
+    }
+
+    /**
+     * Calculate the next city picks probabilites
+     */
+    public void calculateProbabilities(Ant ant) {
+        int i = ant.trail[currentIndex];
+        double pheromone = 0.0;
+        for (int l = 0; l < numberOfCities; l++) {
+            if (!ant.visited(l)) {
+                pheromone += Math.pow(trails[i][l], alpha) * Math.pow(1.0 / graph[i][l], beta);
+            }
+        }
+        for (int j = 0; j < numberOfCities; j++) {
+            if (ant.visited(j)) {
+                probabilities[j] = 0.0;
+            } else {
+                double numerator = Math.pow(trails[i][j], alpha) * Math.pow(1.0 / graph[i][j], beta);
+                probabilities[j] = numerator / pheromone;
+            }
+        }
+    }
+
+    /**
+     * Update trails that ants used
+     */
+    private void updateTrails() {
+        for (int i = 0; i < numberOfCities; i++) {
+            for (int j = 0; j < numberOfCities; j++) {
+                trails[i][j] *= evaporation;
+            }
+        }
+        for (Ant a : ants) {
+            double contribution = Q / a.trailLength(graph);
+            for (int i = 0; i < numberOfCities - 1; i++) {
+                trails[a.trail[i]][a.trail[i + 1]] += contribution;
+            }
+            trails[a.trail[numberOfCities - 1]][a.trail[0]] += contribution;
+        }
+    }
+
+    /**
+     * Update the best solution
+     */
+    private void updateBest() {
+        if (bestTourOrder == null) {
+            bestTourOrder = ants.get(0).trail;
+            bestTourLength = ants.get(0)
+                .trailLength(graph);
+        }
+        for (Ant a : ants) {
+            if (a.trailLength(graph) < bestTourLength) {
+                bestTourLength = a.trailLength(graph);
+                bestTourOrder = a.trail.clone();
+            }
+        }
+    }
+
+    /**
+     * Clear trails after simulation
+     */
+    private void clearTrails() {
+        IntStream.range(0, numberOfCities)
+            .forEach(i -> {
+                IntStream.range(0, numberOfCities)
+                    .forEach(j -> trails[i][j] = c);
+            });
+    }
+
+}
@@ -1,57 +1,57 @@
-package com.baeldung.algorithms.dijkstra;
-
-import java.util.HashSet;
-import java.util.LinkedList;
-import java.util.Map.Entry;
-import java.util.Set;
-
-public class Dijkstra {
-
-    public static Graph calculateShortestPathFromSource(Graph graph, Node source) {
-
-        source.setDistance(0);
-
-        Set<Node> settledNodes = new HashSet<>();
-        Set<Node> unsettledNodes = new HashSet<>();
-        unsettledNodes.add(source);
-
-        while (unsettledNodes.size() != 0) {
-            Node currentNode = getLowestDistanceNode(unsettledNodes);
-            unsettledNodes.remove(currentNode);
-            for (Entry<Node, Integer> adjacencyPair : currentNode.getAdjacentNodes().entrySet()) {
-                Node adjacentNode = adjacencyPair.getKey();
-                Integer edgeWeigh = adjacencyPair.getValue();
-
-                if (!settledNodes.contains(adjacentNode)) {
-                    CalculateMinimumDistance(adjacentNode, edgeWeigh, currentNode);
-                    unsettledNodes.add(adjacentNode);
-                }
-            }
-            settledNodes.add(currentNode);
-        }
-        return graph;
-    }
-
-    private static void CalculateMinimumDistance(Node evaluationNode, Integer edgeWeigh, Node sourceNode) {
-        Integer sourceDistance = sourceNode.getDistance();
-        if (sourceDistance + edgeWeigh < evaluationNode.getDistance()) {
-            evaluationNode.setDistance(sourceDistance + edgeWeigh);
-            LinkedList<Node> shortestPath = new LinkedList<>(sourceNode.getShortestPath());
-            shortestPath.add(sourceNode);
-            evaluationNode.setShortestPath(shortestPath);
-        }
-    }
-
-    private static Node getLowestDistanceNode(Set<Node> unsettledNodes) {
-        Node lowestDistanceNode = null;
-        int lowestDistance = Integer.MAX_VALUE;
-        for (Node node : unsettledNodes) {
-            int nodeDistance = node.getDistance();
-            if (nodeDistance < lowestDistance) {
-                lowestDistance = nodeDistance;
-                lowestDistanceNode = node;
-            }
-        }
-        return lowestDistanceNode;
-    }
-}
+package com.baeldung.algorithms.ga.dijkstra;
+
+import java.util.HashSet;
+import java.util.LinkedList;
+import java.util.Map.Entry;
+import java.util.Set;
+
+public class Dijkstra {
+
+    public static Graph calculateShortestPathFromSource(Graph graph, Node source) {
+
+        source.setDistance(0);
+
+        Set<Node> settledNodes = new HashSet<>();
+        Set<Node> unsettledNodes = new HashSet<>();
+        unsettledNodes.add(source);
+
+        while (unsettledNodes.size() != 0) {
+            Node currentNode = getLowestDistanceNode(unsettledNodes);
+            unsettledNodes.remove(currentNode);
+            for (Entry<Node, Integer> adjacencyPair : currentNode.getAdjacentNodes().entrySet()) {
+                Node adjacentNode = adjacencyPair.getKey();
+                Integer edgeWeigh = adjacencyPair.getValue();
+
+                if (!settledNodes.contains(adjacentNode)) {
+                    CalculateMinimumDistance(adjacentNode, edgeWeigh, currentNode);
+                    unsettledNodes.add(adjacentNode);
+                }
+            }
+            settledNodes.add(currentNode);
+        }
+        return graph;
+    }
+
+    private static void CalculateMinimumDistance(Node evaluationNode, Integer edgeWeigh, Node sourceNode) {
+        Integer sourceDistance = sourceNode.getDistance();
+        if (sourceDistance + edgeWeigh < evaluationNode.getDistance()) {
+            evaluationNode.setDistance(sourceDistance + edgeWeigh);
+            LinkedList<Node> shortestPath = new LinkedList<>(sourceNode.getShortestPath());
+            shortestPath.add(sourceNode);
+            evaluationNode.setShortestPath(shortestPath);
+        }
+    }
+
+    private static Node getLowestDistanceNode(Set<Node> unsettledNodes) {
+        Node lowestDistanceNode = null;
+        int lowestDistance = Integer.MAX_VALUE;
+        for (Node node : unsettledNodes) {
+            int nodeDistance = node.getDistance();
+            if (nodeDistance < lowestDistance) {
+                lowestDistance = nodeDistance;
+                lowestDistanceNode = node;
+            }
+        }
+        return lowestDistanceNode;
+    }
+}
@@ -1,21 +1,21 @@
-package com.baeldung.algorithms.dijkstra;
-
-import java.util.HashSet;
-import java.util.Set;
-
-public class Graph {
-
-    private Set<Node> nodes = new HashSet<>();
-
-    public void addNode(Node nodeA) {
-        nodes.add(nodeA);
-    }
-
-    public Set<Node> getNodes() {
-        return nodes;
-    }
-
-    public void setNodes(Set<Node> nodes) {
-        this.nodes = nodes;
-    }
-}
+package com.baeldung.algorithms.ga.dijkstra;
+
+import java.util.HashSet;
+import java.util.Set;
+
+public class Graph {
+
+    private Set<Node> nodes = new HashSet<>();
+
+    public void addNode(Node nodeA) {
+        nodes.add(nodeA);
+    }
+
+    public Set<Node> getNodes() {
+        return nodes;
+    }
+
+    public void setNodes(Set<Node> nodes) {
+        this.nodes = nodes;
+    }
+}
@@ -1,58 +1,58 @@
-package com.baeldung.algorithms.dijkstra;
-
-import java.util.HashMap;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.Map;
-
-public class Node {
-
-    private String name;
-
-    private LinkedList<Node> shortestPath = new LinkedList<>();
-
-    private Integer distance = Integer.MAX_VALUE;
-
-    private Map<Node, Integer> adjacentNodes = new HashMap<>();
-
-    public Node(String name) {
-        this.name = name;
-    }
-
-    public void addDestination(Node destination, int distance) {
-        adjacentNodes.put(destination, distance);
-    }
-
-    public String getName() {
-        return name;
-    }
-
-    public void setName(String name) {
-        this.name = name;
-    }
-
-    public Map<Node, Integer> getAdjacentNodes() {
-        return adjacentNodes;
-    }
-
-    public void setAdjacentNodes(Map<Node, Integer> adjacentNodes) {
-        this.adjacentNodes = adjacentNodes;
-    }
-
-    public Integer getDistance() {
-        return distance;
-    }
-
-    public void setDistance(Integer distance) {
-        this.distance = distance;
-    }
-
-    public List<Node> getShortestPath() {
-        return shortestPath;
-    }
-
-    public void setShortestPath(LinkedList<Node> shortestPath) {
-        this.shortestPath = shortestPath;
-    }
-
-}
+package com.baeldung.algorithms.ga.dijkstra;
+
+import java.util.HashMap;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+
+public class Node {
+
+    private String name;
+
+    private LinkedList<Node> shortestPath = new LinkedList<>();
+
+    private Integer distance = Integer.MAX_VALUE;
+
+    private Map<Node, Integer> adjacentNodes = new HashMap<>();
+
+    public Node(String name) {
+        this.name = name;
+    }
+
+    public void addDestination(Node destination, int distance) {
+        adjacentNodes.put(destination, distance);
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public Map<Node, Integer> getAdjacentNodes() {
+        return adjacentNodes;
+    }
+
+    public void setAdjacentNodes(Map<Node, Integer> adjacentNodes) {
+        this.adjacentNodes = adjacentNodes;
+    }
+
+    public Integer getDistance() {
+        return distance;
+    }
+
+    public void setDistance(Integer distance) {
+        this.distance = distance;
+    }
+
+    public List<Node> getShortestPath() {
+        return shortestPath;
+    }
+
+    public void setShortestPath(LinkedList<Node> shortestPath) {
+        this.shortestPath = shortestPath;
+    }
+
+}
@@ -0,0 +1,47 @@
+package com.baeldung.algorithms.ga.jenetics;
+
+import static org.jenetics.engine.EvolutionResult.toBestPhenotype;
+import static org.jenetics.engine.limit.bySteadyFitness;
+
+import java.util.stream.Stream;
+
+import org.jenetics.BitChromosome;
+import org.jenetics.BitGene;
+import org.jenetics.Mutator;
+import org.jenetics.Phenotype;
+import org.jenetics.RouletteWheelSelector;
+import org.jenetics.SinglePointCrossover;
+import org.jenetics.TournamentSelector;
+import org.jenetics.engine.Engine;
+import org.jenetics.engine.EvolutionStatistics;
+
+//The main class.
+public class Knapsack {
+
+    public static void main(String[] args) {
+        int nItems = 15;
+        double ksSize = nItems * 100.0 / 3.0;
+
+        KnapsackFF ff = new KnapsackFF(Stream.generate(KnapsackItem::random)
+            .limit(nItems)
+            .toArray(KnapsackItem[]::new), ksSize);
+
+        Engine<BitGene, Double> engine = Engine.builder(ff, BitChromosome.of(nItems, 0.5))
+            .populationSize(500)
+            .survivorsSelector(new TournamentSelector<>(5))
+            .offspringSelector(new RouletteWheelSelector<>())
+            .alterers(new Mutator<>(0.115), new SinglePointCrossover<>(0.16))
+            .build();
+
+        EvolutionStatistics<Double, ?> statistics = EvolutionStatistics.ofNumber();
+
+        Phenotype<BitGene, Double> best = engine.stream()
+            .limit(bySteadyFitness(7))
+            .limit(100)
+            .peek(statistics)
+            .collect(toBestPhenotype());
+
+        System.out.println(statistics);
+        System.out.println(best);
+    }
+}
@@ -0,0 +1,25 @@
+package com.baeldung.algorithms.ga.jenetics;
+
+import java.util.function.Function;
+
+import org.jenetics.BitChromosome;
+import org.jenetics.BitGene;
+import org.jenetics.Genotype;
+
+public class KnapsackFF implements Function<Genotype<BitGene>, Double> {
+    private KnapsackItem[] items;
+    private double size;
+
+    public KnapsackFF(KnapsackItem[] items, double size) {
+        this.items = items;
+        this.size = size;
+    }
+
+    @Override
+    public Double apply(Genotype<BitGene> gt) {
+        KnapsackItem sum = ((BitChromosome) gt.getChromosome()).ones()
+            .mapToObj(i -> items[i])
+            .collect(KnapsackItem.toSum());
+        return sum.size <= this.size ? sum.value : 0;
+    }
+}
@@ -0,0 +1,34 @@
+package com.baeldung.algorithms.ga.jenetics;
+
+import java.util.Random;
+import java.util.stream.Collector;
+
+import org.jenetics.util.RandomRegistry;
+
+public class KnapsackItem {
+
+    public double size;
+    public double value;
+
+    public KnapsackItem(double size, double value) {
+        this.size = size;
+        this.value = value;
+    }
+
+    protected static KnapsackItem random() {
+        Random r = RandomRegistry.getRandom();
+        return new KnapsackItem(r.nextDouble() * 100, r.nextDouble() * 100);
+    }
+
+    protected static Collector<KnapsackItem, ?, KnapsackItem> toSum() {
+        return Collector.of(() -> new double[2], (a, b) -> {
+            a[0] += b.size;
+            a[1] += b.value;
+        } , (a, b) -> {
+            a[0] += b[0];
+            a[1] += b[1];
+            return a;
+        } , r -> new KnapsackItem(r[0], r[1]));
+    }
+
+}
@@ -0,0 +1,33 @@
+package com.baeldung.algorithms.ga.jenetics;
+
+import org.jenetics.BitChromosome;
+import org.jenetics.BitGene;
+import org.jenetics.Genotype;
+import org.jenetics.engine.Engine;
+import org.jenetics.engine.EvolutionResult;
+import org.jenetics.util.Factory;
+
+public class SimpleGeneticAlgorithm {
+
+    private static Integer eval(Genotype<BitGene> gt) {
+        return gt.getChromosome()
+            .as(BitChromosome.class)
+            .bitCount();
+    }
+
+    public static void main(String[] args) {
+        Factory<Genotype<BitGene>> gtf = Genotype.of(BitChromosome.of(10, 0.5));
+        System.out.println("Before the evolution:\n" + gtf);
+
+        Engine<BitGene, Integer> engine = Engine.builder(SimpleGeneticAlgorithm::eval, gtf)
+            .build();
+
+        Genotype<BitGene> result = engine.stream()
+            .limit(500)
+            .collect(EvolutionResult.toBestGenotype());
+
+        System.out.println("After the evolution:\n" + result);
+
+    }
+
+}
@@ -0,0 +1,86 @@
+package com.baeldung.algorithms.ga.jenetics;
+
+import static java.util.Objects.requireNonNull;
+
+import java.util.function.Function;
+import java.util.stream.Collectors;
+
+import org.jenetics.BitGene;
+import org.jenetics.engine.Codec;
+import org.jenetics.engine.Engine;
+import org.jenetics.engine.EvolutionResult;
+import org.jenetics.engine.Problem;
+import org.jenetics.engine.codecs;
+import org.jenetics.util.ISeq;
+
+public class SpringsteenProblem implements Problem<ISeq<SpringsteenRecord>, BitGene, Double> {
+
+    private ISeq<SpringsteenRecord> records;
+    private double maxPricePerUniqueSong;
+
+    public SpringsteenProblem(ISeq<SpringsteenRecord> records, double maxPricePerUniqueSong) {
+        this.records = requireNonNull(records);
+        this.maxPricePerUniqueSong = maxPricePerUniqueSong;
+    }
+
+    @Override
+    public Function<ISeq<SpringsteenRecord>, Double> fitness() {
+        return SpringsteenRecords -> {
+            double cost = SpringsteenRecords.stream()
+                .mapToDouble(r -> r.price)
+                .sum();
+
+            int uniqueSongCount = SpringsteenRecords.stream()
+                .flatMap(r -> r.songs.stream())
+                .collect(Collectors.toSet())
+                .size();
+
+            double pricePerUniqueSong = cost / uniqueSongCount;
+
+            return pricePerUniqueSong <= maxPricePerUniqueSong ? uniqueSongCount : 0.0;
+        };
+    }
+
+    @Override
+    public Codec<ISeq<SpringsteenRecord>, BitGene> codec() {
+        return codecs.ofSubSet(records);
+    }
+
+    public static void main(String[] args) {
+        double maxPricePerUniqueSong = 2.5;
+
+        SpringsteenProblem springsteen = new SpringsteenProblem(
+            ISeq.of(new SpringsteenRecord("SpringsteenRecord1", 25, ISeq.of("Song1", "Song2", "Song3", "Song4", "Song5", "Song6")), new SpringsteenRecord("SpringsteenRecord2", 15, ISeq.of("Song2", "Song3", "Song4", "Song5", "Song6", "Song7")),
+                new SpringsteenRecord("SpringsteenRecord3", 35, ISeq.of("Song5", "Song6", "Song7", "Song8", "Song9", "Song10")), new SpringsteenRecord("SpringsteenRecord4", 17, ISeq.of("Song9", "Song10", "Song12", "Song4", "Song13", "Song14")),
+                new SpringsteenRecord("SpringsteenRecord5", 29, ISeq.of("Song1", "Song2", "Song13", "Song14", "Song15", "Song16")), new SpringsteenRecord("SpringsteenRecord6", 5, ISeq.of("Song18", "Song20", "Song30", "Song40"))),
+            maxPricePerUniqueSong);
+
+        Engine<BitGene, Double> engine = Engine.builder(springsteen)
+            .build();
+
+        ISeq<SpringsteenRecord> result = springsteen.codec()
+            .decoder()
+            .apply(engine.stream()
+                .limit(10)
+                .collect(EvolutionResult.toBestGenotype()));
+
+        double cost = result.stream()
+            .mapToDouble(r -> r.price)
+            .sum();
+
+        int uniqueSongCount = result.stream()
+            .flatMap(r -> r.songs.stream())
+            .collect(Collectors.toSet())
+            .size();
+
+        double pricePerUniqueSong = cost / uniqueSongCount;
+
+        System.out.println("Overall cost:  " + cost);
+        System.out.println("Unique songs:  " + uniqueSongCount);
+        System.out.println("Cost per song: " + pricePerUniqueSong);
+        System.out.println("Records:       " + result.map(r -> r.name)
+            .toString(", "));
+
+    }
+
+}
@@ -0,0 +1,24 @@
+package com.baeldung.algorithms.ga.jenetics;
+
+import static java.util.Objects.requireNonNull;
+
+import org.jenetics.util.ISeq;
+
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Data
+@NoArgsConstructor
+public class SpringsteenRecord {
+
+    String name;
+    double price;
+    ISeq<String> songs;
+
+    public SpringsteenRecord(String name, double price, ISeq<String> songs) {
+        this.name = requireNonNull(name);
+        this.price = price;
+        this.songs = requireNonNull(songs);
+    }
+
+}
@@ -0,0 +1,66 @@
+package com.baeldung.algorithms.ga.jenetics;
+
+import static java.util.Objects.requireNonNull;
+
+import java.util.Random;
+import java.util.function.Function;
+
+import org.jenetics.EnumGene;
+import org.jenetics.Mutator;
+import org.jenetics.PartiallyMatchedCrossover;
+import org.jenetics.Phenotype;
+import org.jenetics.engine.Codec;
+import org.jenetics.engine.Engine;
+import org.jenetics.engine.EvolutionResult;
+import org.jenetics.engine.Problem;
+import org.jenetics.engine.codecs;
+import org.jenetics.engine.limit;
+import org.jenetics.util.ISeq;
+import org.jenetics.util.LCG64ShiftRandom;
+
+public class SubsetSum implements Problem<ISeq<Integer>, EnumGene<Integer>, Integer> {
+
+    private ISeq<Integer> basicSet;
+    private int size;
+
+    public SubsetSum(ISeq<Integer> basicSet, int size) {
+        this.basicSet = requireNonNull(basicSet);
+        this.size = size;
+    }
+
+    @Override
+    public Function<ISeq<Integer>, Integer> fitness() {
+        return subset -> Math.abs(subset.stream()
+            .mapToInt(Integer::intValue)
+            .sum());
+    }
+
+    @Override
+    public Codec<ISeq<Integer>, EnumGene<Integer>> codec() {
+        return codecs.ofSubSet(basicSet, size);
+    }
+
+    public static SubsetSum of(int n, int k, Random random) {
+        return new SubsetSum(random.doubles()
+            .limit(n)
+            .mapToObj(d -> (int) ((d - 0.5) * n))
+            .collect(ISeq.toISeq()), k);
+    }
+
+    public static void main(String[] args) {
+        SubsetSum problem = of(500, 15, new LCG64ShiftRandom(101010));
+
+        Engine<EnumGene<Integer>, Integer> engine = Engine.builder(problem)
+            .minimizing()
+            .maximalPhenotypeAge(5)
+            .alterers(new PartiallyMatchedCrossover<>(0.4), new Mutator<>(0.3))
+            .build();
+
+        Phenotype<EnumGene<Integer>, Integer> result = engine.stream()
+            .limit(limit.bySteadyFitness(55))
+            .collect(EvolutionResult.toBestPhenotype());
+
+        System.out.print(result);
+    }
+
+}
@@ -0,0 +1,67 @@
+package com.baeldung.algorithms.ga.jenetics;
+
+import static java.lang.Math.PI;
+import static java.lang.Math.abs;
+import static java.lang.Math.sin;
+import static org.jenetics.engine.EvolutionResult.toBestPhenotype;
+import static org.jenetics.engine.limit.bySteadyFitness;
+
+import java.util.stream.IntStream;
+
+import org.jenetics.EnumGene;
+import org.jenetics.Optimize;
+import org.jenetics.PartiallyMatchedCrossover;
+import org.jenetics.Phenotype;
+import org.jenetics.SwapMutator;
+import org.jenetics.engine.Engine;
+import org.jenetics.engine.EvolutionStatistics;
+import org.jenetics.engine.codecs;
+
+public class TravelingSalesman {
+
+    private static final int STOPS = 50;
+    private static final double[][] ADJACENCE = matrix(STOPS);
+
+    private static double[][] matrix(int stops) {
+        final double radius = 100.0;
+        double[][] matrix = new double[stops][stops];
+
+        for (int i = 0; i < stops; ++i) {
+            for (int j = 0; j < stops; ++j) {
+                matrix[i][j] = chord(stops, abs(i - j), radius);
+            }
+        }
+        return matrix;
+    }
+
+    private static double chord(int stops, int i, double r) {
+        return 2.0 * r * abs(sin(PI * i / stops));
+    }
+
+    private static double dist(final int[] path) {
+        return IntStream.range(0, STOPS)
+            .mapToDouble(i -> ADJACENCE[path[i]][path[(i + 1) % STOPS]])
+            .sum();
+    }
+
+    public static void main(String[] args) {
+        final Engine<EnumGene<Integer>, Double> engine = Engine.builder(TravelingSalesman::dist, codecs.ofPermutation(STOPS))
+            .optimize(Optimize.MINIMUM)
+            .maximalPhenotypeAge(11)
+            .populationSize(500)
+            .alterers(new SwapMutator<>(0.2), new PartiallyMatchedCrossover<>(0.35))
+            .build();
+
+        final EvolutionStatistics<Double, ?> statistics = EvolutionStatistics.ofNumber();
+
+        final Phenotype<EnumGene<Integer>, Double> best = engine.stream()
+            .limit(bySteadyFitness(15))
+            .limit(250)
+            .peek(statistics)
+            .collect(toBestPhenotype());
+
+        System.out.println(statistics);
+        System.out.println(best);
+    }
+
+}
--- a/Show More
+++ b/Show More