Optaplanner add computerroom restriction

问题

it's my first post here and I'm posting for my team of learning Java programmer for an school project. So we aren't good programmer. how can I add a constraint to make the Optaplanner move the lectures into a specific room type. For example I want to move the lecture "Programming" into a computerroom and the lecture "Math" in a normal room. But with my constraint it declares the hard constraints but doesn't move the lectures in their room. This should be a negative constraint. So the negative score for this hard constraint is shown, but it still won't be resolved/moved.

Here's the constraint:

rule "computerroom"
    when
       $room : Room($computerroom : computerroom)
       $course : Course(computerroom == $computerroom)
    then
        scoreHolder.addHardConstraintMatch(kcontext, -1);
end

We added a new variable to the class Room, that look like:

package org.optaplanner.examples.curriculumcourse.domain;

import com.thoughtworks.xstream.annotations.XStreamAlias;
import org.optaplanner.examples.common.domain.AbstractPersistable;

@XStreamAlias("Room")
public class Room extends AbstractPersistable {

    private String code;
    private int capacity;
    private boolean computerroom;

    public String getCode() {
        return code;
    }

    public void setCode(String code) {
        this.code = code;
    }

    public boolean getComputerroom() {
        return computerroom;
    }

    public void setComputerroom(boolean computerroom) {
        this.computerroom = computerroom;
    }

    public int getCapacity() {
        return capacity;
    }

    public void setCapacity(int capacity) {
        this.capacity = capacity;
    }

    public String getLabel() {
        return code;
    }

    @Override
    public String toString() {
        return code + " {C" + capacity + "}";
    }

}

So have u got an advise for us?

Another little thing: the Optaplanner gets a lot of data to work with: How can we increase the maximun seconds spend for resolving? Because we tried other values over 1152 but it does't work. It's only a little question, the constraint is more important, but we would be happy to get the program running!

Greets SEP2014

回答1:

That score rule isn't checking anything that is "planning variable" (= a variable that changes during solving). So it's static, it can never have a different score than with what it starts out with.

Consider this instead:

rule "computerroom"
  when
    // If there's a room which has no computer
    $r : Room(hasComputer == false)
    // And we're putting a course which needs a computer in that room
    $course : Course(needsComputer == true, room == $r)
  then
    scoreHolder.addHardConstraintMatch(kcontext, -1);
end

The important thing here is Course(..., room == $r). That room is a planning variable: it changes during planning.

Note: this one doesn't punish courses that don't need a computer if they use a computer room (but that's easily changed).

Same rule, but written shorter and more efficiently:

rule "computerroom"
  when
    $course : Course(needsComputer == true, room != null, room.hasComputer == false)
  then
    scoreHolder.addHardConstraintMatch(kcontext, -1);
end

来源：https://stackoverflow.com/questions/25787865/optaplanner-add-computerroom-restriction

标签

java

constraints

optaplanner