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

optaplanner/README.md

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+## OptaPlanner
+
+This module contains articles about OptaPlanner.
+
+### Relevant articles
+
+- [A Guide to OptaPlanner](https://www.baeldung.com/opta-planner)

optaplanner/pom.xml

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+<?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>
+    <artifactId>optaplanner</artifactId>
+	<name>optaplanner</name>
+
+    <parent>
+        <artifactId>parent-modules</artifactId>
+        <groupId>com.baeldung</groupId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.optaplanner</groupId>
+            <artifactId>optaplanner-core</artifactId>
+            <version>${optaplanner-core.version}</version>
+        </dependency>
+    </dependencies>
+
+	<properties>
+		<optaplanner-core.version>7.9.0.Final</optaplanner-core.version>
+	</properties>
+
+</project>

optaplanner/src/main/java/com/baeldung/optaplanner/CourseSchedule.java

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+package com.baeldung.optaplanner;
+
+import org.optaplanner.core.api.domain.solution.PlanningEntityCollectionProperty;
+import org.optaplanner.core.api.domain.solution.PlanningScore;
+import org.optaplanner.core.api.domain.solution.PlanningSolution;
+import org.optaplanner.core.api.domain.solution.drools.ProblemFactCollectionProperty;
+import org.optaplanner.core.api.domain.valuerange.ValueRangeProvider;
+import org.optaplanner.core.api.score.buildin.hardsoft.HardSoftScore;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.ArrayList;
+import java.util.List;
+
+@PlanningSolution
+public class CourseSchedule {
+
+    Logger logger = LoggerFactory.getLogger("CourseSchedule");
+
+    private List<Integer> roomList;
+    private List<Integer> periodList;
+    private List<Lecture> lectureList;
+    private HardSoftScore score;
+
+    public CourseSchedule(){
+        roomList = new ArrayList<>();
+        periodList = new ArrayList<>();
+        lectureList = new ArrayList<>();
+    }
+
+    @ValueRangeProvider(id = "availableRooms")
+    @ProblemFactCollectionProperty
+    public List<Integer> getRoomList() {
+        return roomList;
+    }
+
+    @ValueRangeProvider(id = "availablePeriods")
+    @ProblemFactCollectionProperty
+    public List<Integer> getPeriodList() {
+        return periodList;
+    }
+
+    @PlanningEntityCollectionProperty
+    public List<Lecture> getLectureList() {
+        return lectureList;
+    }
+
+    @PlanningScore
+    public HardSoftScore getScore() {
+        return score;
+    }
+
+    public void setScore(HardSoftScore score) {
+        this.score = score;
+    }
+
+    public void printCourseSchedule() {
+        lectureList.stream()
+                .map(c -> "Lecture in Room " + c.getRoomNumber().toString() + " during Period " + c.getPeriod().toString())
+                .forEach(k -> logger.info(k));
+    }
+
+}

optaplanner/src/main/java/com/baeldung/optaplanner/Lecture.java

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+package com.baeldung.optaplanner;
+
+import org.optaplanner.core.api.domain.entity.PlanningEntity;
+import org.optaplanner.core.api.domain.variable.PlanningVariable;
+
+@PlanningEntity
+public class Lecture {
+
+    private Integer roomNumber;
+    private Integer period;
+
+    @PlanningVariable(valueRangeProviderRefs = {"availablePeriods"})
+    public Integer getPeriod() {
+        return period;
+    }
+
+    @PlanningVariable(valueRangeProviderRefs = {"availableRooms"})
+    public Integer getRoomNumber() {
+        return roomNumber;
+    }
+
+    public void setPeriod(Integer period) {
+        this.period = period;
+    }
+
+    public void setRoomNumber(Integer roomNumber) {
+        this.roomNumber = roomNumber;
+    }
+
+}

optaplanner/src/main/java/com/baeldung/optaplanner/ScoreCalculator.java

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+package com.baeldung.optaplanner;
+
+import org.optaplanner.core.api.score.Score;
+import org.optaplanner.core.api.score.buildin.hardsoft.HardSoftScore;
+import org.optaplanner.core.impl.score.director.easy.EasyScoreCalculator;
+
+import java.util.HashSet;
+
+public class ScoreCalculator implements EasyScoreCalculator<CourseSchedule> {
+
+    @Override
+    public Score calculateScore(CourseSchedule courseSchedule) {
+        int hardScore = 0;
+        int softScore = 0;
+
+        HashSet<String> occupiedRooms = new HashSet<>();
+        for (Lecture lecture : courseSchedule.getLectureList()) {
+            if(lecture.getPeriod() != null && lecture.getRoomNumber() != null) {
+                String roomInUse = lecture.getPeriod().toString() + ":" + lecture.getRoomNumber().toString();
+                if (occupiedRooms.contains(roomInUse)) {
+                    hardScore += -1;
+                } else {
+                    occupiedRooms.add(roomInUse);
+                }
+            } else {
+                hardScore += -1;
+            }
+        }
+
+        return HardSoftScore.valueOf(hardScore, softScore);
+    }
+}

optaplanner/src/main/resources/courseSchedule.drl

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+package com.baeldung.optaplanner
+
+import com.baeldung.optaplanner.Lecture;
+import org.optaplanner.core.api.score.buildin.hardsoft.HardSoftScoreHolder;
+
+global HardSoftScoreHolder scoreHolder;
+
+rule "noNullRoomPeriod"
+    when
+        Lecture( roomNumber == null );
+        Lecture( period == null );
+    then
+        scoreHolder.addHardConstraintMatch(kcontext, -1);
+end

optaplanner/src/main/resources/courseScheduleSolverConfigDrools.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<solver>
+    <scanAnnotatedClasses/>
+
+    <scoreDirectorFactory>
+        <scoreDrl>courseSchedule.drl</scoreDrl>
+    </scoreDirectorFactory>
+
+    <termination>
+        <secondsSpentLimit>10</secondsSpentLimit>
+    </termination>
+</solver>

optaplanner/src/main/resources/courseScheduleSolverConfiguration.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<solver>
+    <scanAnnotatedClasses/>
+
+    <scoreDirectorFactory>
+        <easyScoreCalculatorClass>com.baeldung.optaplanner.ScoreCalculator</easyScoreCalculatorClass>
+    </scoreDirectorFactory>
+
+    <termination>
+        <secondsSpentLimit>10</secondsSpentLimit>
+    </termination>
+</solver>

optaplanner/src/main/resources/logback.xml

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+<configuration>
+    <logger name="org.optaplanner" level="info"/>
+</configuration>

optaplanner/src/test/java/com/baeldung/optaplanner/test/OptaPlannerUnitTest.java

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+package com.baeldung.optaplanner.test;
+
+import com.baeldung.optaplanner.CourseSchedule;
+import com.baeldung.optaplanner.Lecture;
+import org.junit.Assert;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+import org.optaplanner.core.api.solver.Solver;
+import org.optaplanner.core.api.solver.SolverFactory;
+import java.util.Arrays;
+
+public class OptaPlannerUnitTest {
+
+    static CourseSchedule unsolvedCourseSchedule;
+
+    @BeforeAll
+    public static void setUp() {
+
+        unsolvedCourseSchedule = new CourseSchedule();
+
+        for(int i = 0; i < 10; i++){
+            unsolvedCourseSchedule.getLectureList().add(new Lecture());
+        }
+
+        unsolvedCourseSchedule.getPeriodList().addAll(Arrays.asList(new Integer[] { 1, 2, 3 }));
+        unsolvedCourseSchedule.getRoomList().addAll(Arrays.asList(new Integer[] { 1, 2 }));
+    }
+
+    @Test
+    public void test_whenCustomJavaSolver() {
+
+        SolverFactory<CourseSchedule> solverFactory = SolverFactory.createFromXmlResource("courseScheduleSolverConfiguration.xml");
+        Solver<CourseSchedule> solver = solverFactory.buildSolver();
+        CourseSchedule solvedCourseSchedule = solver.solve(unsolvedCourseSchedule);
+
+        Assert.assertNotNull(solvedCourseSchedule.getScore());
+        Assert.assertEquals(-4, solvedCourseSchedule.getScore().getHardScore());
+    }
+
+    @Test
+    public void test_whenDroolsSolver() {
+
+        SolverFactory<CourseSchedule> solverFactory = SolverFactory.createFromXmlResource("courseScheduleSolverConfigDrools.xml");
+        Solver<CourseSchedule> solver = solverFactory.buildSolver();
+        CourseSchedule solvedCourseSchedule = solver.solve(unsolvedCourseSchedule);
+
+        Assert.assertNotNull(solvedCourseSchedule.getScore());
+        Assert.assertEquals(0, solvedCourseSchedule.getScore().getHardScore());
+    }
+}