Optaplanner with Hibernate - some DRL rules not working

Question

I am making an application for employee rostering using Optaplanner. Everything worked just fine without persistence. Now, I want to add Hibernate integration. I want to take information from MySQL database and use it as a schedule input.

In database I have Position and Skill tables.

Employees data, TimeSlots and Assignments are now hardcoded in app.

My domain classes, Skill:

import javax.persistence.*;

@Entity
@Table(name = "SKILL")
public class Skill {

    private long skillId;
    private String name;

    public Skill(String name) {
        this.name = name;
    }

    public Skill() {}

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "SKILL_ID")
    public long getSkillId() {
        return this.skillId;
    }

    public void setSkillId(long skillId) {
        this.skillId = skillId;
    }

    @Column(name = "SKILL_NAME", nullable = false, length=250)
    public String getSkillName() {
        return this.name;
    }

    public void setSkillName(String skillName) {
        this.name = skillName;
    }

    @Override
    public String toString() {
        return name;
    }

}

and Position:

import javax.persistence.*;

@Entity
@Table(name = "POSITION")
public class Position {

    private long positionId;
    private String name;
    private Skill requiredSkill;

    public Position(String name, Skill requiredSkill) {
        this.name = name;
        this.requiredSkill = requiredSkill;
    }

    public Position() {}

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "POSITION_ID")
    public long getPositionId() {
        return this.positionId;
    }

    public void setPositionId(long positionId) {
        this.positionId = positionId;
    }

    @Column(name="POSITION_NAME", nullable=false, length = 100)
    public String getPositionName() {
        return this.name;
    }

    public void setPositionName(String positionName) {
        this.name = positionName;
    }

    @OneToOne(cascade = CascadeType.ALL)
    public Skill getRequiredSkill() {
        return this.requiredSkill;
    }

    public void setRequiredSkill(Skill requiredSkill) {
        this.requiredSkill = requiredSkill;
    }

    @Override
    public String toString() {
        return name;
    }
}

Rule which is not working:

rule "Employee works only on positions with skills he has"
    when
        Assignment(
                employee != null,
                !getEmployee().getSkillSet().contains(getPosition().getRequiredSkill()))
    then
        scoreHolder.addHardConstraintMatch(kcontext, -100);
end

I think database is ok, because data in it was created using this app before. Also, I have another DRL rule which is working. I don't get any warnings/errors - just the aforementioned rule is not taken into account during solving.

During solving I get:

08:40:11.453 [main] DEBUG org.drools.core.common.DefaultAgenda - State was INACTIVE is now FIRING_ALL_RULES
08:40:11.453 [main] DEBUG org.drools.core.common.DefaultAgenda - State was FIRING_ALL_RULES is now HALTING
08:40:11.453 [main] DEBUG org.drools.core.common.DefaultAgenda - State was HALTING is now INACTIVE
08:40:11.453 [main] DEBUG org.optaplanner.core.impl.constructionheuristic.DefaultConstructionHeuristicPhase -     CH step (1), time spent (134), score (-14init/-202hard/0soft), selected move count (7), picked move (domain.Assignment@4d354a3e {null -> domain.Employee@1511d157}).

Also, at the beggining I get this warning:

Failed to add the foreign key constraint. Missing index for constraint 'FKqx7n7alhjrnaw173dc48i47y0' in the referenced table 'skill'

Answer 1

Take a look at how we added JPA-hibernate persistence in optaweb-employee-rostering.

Specifically, the optimistic locking on Shift class provided a challenge, which we fixed like this.