Timefold员工排班：标记硬约束违规班次可行性问询

Timefold完全可以满足你的需求，以下是具体实现方案：

1. 标记违反硬约束的Shift对象 #

方式一：在DRL规则中直接标记实体 #

在Shift实体类中添加一个布尔字段用于标记是否违反硬约束：

public class Shift {
    private boolean hardConstraintViolated;
    // 其他字段、getter、setter
    public boolean isHardConstraintViolated() {
        return hardConstraintViolated;
    }
    public void setHardConstraintViolated(boolean hardConstraintViolated) {
        this.hardConstraintViolated = hardConstraintViolated;
    }
}

在DRL规则文件中，当触发硬约束违规时，设置该标记：

rule "禁止员工连续12小时内排两个班次"
    when
        Shift($employee : employee, $currentShift : this, hardConstraintViolated == false)
        Shift(employee == $employee, startDate after $currentShift.endDate, startDate before $currentShift.endDate.plusHours(12))
    then
        scoreHolder.addHardConstraintMatch(kcontext, -1);
        $currentShift.setHardConstraintViolated(true);
end

方式二：利用Timefold约束匹配查询 #

无需修改实体类，直接通过Timefold的约束匹配API获取违规的Shift：

// 求解完成后获取结果
MyRosterSolution solution = solver.solve(problem);
Score totalScore = solution.getScore();

if (totalScore.getHardScore() < 0) {
    // 遍历所有硬约束的匹配结果
    for (ConstraintMatchTotal<?> constraintMatchTotal : solver.getConstraintMatchTotalMap().values()) {
        if (constraintMatchTotal.getScore().getHardScore() < 0) {
            // 获取该约束下所有违规的Shift实例
            for (ConstraintMatch<?> match : constraintMatchTotal.getConstraintMatchSet()) {
                Shift violatedShift = (Shift) match.getJustificationList().get(0);
                // 可在此处对违规Shift做标记或收集
            }
        }
    }
}

2. 筛选符合硬约束的班次与员工组合 #

求解完成后，通过标记或约束匹配结果筛选合规数据：

// 基于实体标记筛选
List<Shift> compliantShifts = solution.getShifts().stream()
    .filter(shift -> !shift.isHardConstraintViolated())
    .collect(Collectors.toList());

// 或基于约束匹配结果筛选（需先收集违规Shift）
Set<Shift> violatedShiftSet = new HashSet<>();
// 先通过约束匹配API填充violatedShiftSet...
List<Shift> compliantShifts = solution.getShifts().stream()
    .filter(shift -> !violatedShiftSet.contains(shift))
    .collect(Collectors.toList());

内容的提问来源于stack exchange，提问作者naokeziteng