java - ArrayList 中的 getDayOfWeek 等于自身，但 getYear 不等于

Question

为什么下面的代码用 getDayOfWeek 打印 true 但用 getYear 打印 false？

    LocalDate date = LocalDate.now();
    ArrayList<Object> dateData = new ArrayList<Object>();
    dateData.add(date.getDayOfWeek());
    dateData.add(date.getDayOfWeek());
    System.out.println( dateData.get(0) == dateData.get(1));  // prints true 

    dateData.clear();
    dateData.add(date.getYear());
    dateData.add(date.getYear());
    System.out.println( dateData.get(0) == dateData.get(1));  // prints false