JAVA - LocalDate.plusDay() 无法正常工作 [重复]

Question

我想创建将属于某个 trainingCycle 的培训添加到日历的方法。可能我犯了一些错误，因为它将所有培训添加到只有一天。

TrainingCycle 模型类：

@DynamoDBTable(tableName = "trainingCycle")
public class TrainingCycle extends Request {
private String id;
private String cycleName;
private Long cycleTime;
private LocalDateTime startTime;
private List<List<Training>> trainingsForDay;

训练模型类：

@DynamoDBTable(tableName = "training")
@DynamoDBDocument
public class Training extends Request {

private String id;
private String trainingName;
private Integer predictedCaloriesToBurn;
private Integer burnedCalories;
private LocalDateTime startTime;
private LocalDateTime endTime;
private List<Exercise> exerciseList;
private List<TrainingLabels> trainingLabels;
private boolean approved;
private ActivityDay activityDay;

AddTrainingCycle 方法：

    public List<Day> addTrainingCycle(String userId, TrainingCycle trainingCycle, LocalDate localDate) {

    List<Day> days = new ArrayList<>();
    for (List<Training> trainings : trainingCycle.getTrainingsForDay()) {
        if (trainings == null || trainings.isEmpty()) {
            localDate.plusDays(1);
        } else {
            Day actualDay = getActivityBoardDay(localDate, userId);
            actualDay.getTrainings().addAll(trainings);
            localDate.plusDays(1);
            days.add(actualDay);
        }
    }
    return days;
}

我已经创建了测试方法，正如我所说的 - 它添加了所有的训练，但只是从争论开始的一天，它并没有增加 LocalDate。有人可以帮我吗？

Answer 1

LocalDate 是不可变的。

localDate.plusDays(1) 不会修改当前的localDate。它返回当前日期加一的新值。

你必须重新分配它：

localDate = localDate.plusDays(1);