Calender设置固定时间遇到的问题

Posted 2020-08-25 SonoFelice——棣琦

在使用Calender获取实例，设置成UTC时区时，发现比我们常规的月份多了一个月：

示例代码如下：

Calendar calendar = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
calendar.set(2016, 9, 11, 16, 0, 0);
System.out.println(calendar.getTime());

打印的结果为：

Wed Oct 12 00:00:00 CST 2016

即2016-10-12 00：00：00，比我们设置的月份多了一个月。

我们来看下calender中set的源码：

    /**
     * Sets the values for the fields <code>YEAR</code>, <code>MONTH</code>,
     * <code>DAY_OF_MONTH</code>, <code>HOUR_OF_DAY</code>, <code>MINUTE</code>, and
     * <code>SECOND</code>.
     * Previous values of other fields are retained.  If this is not desired,
     * call {@link #clear()} first.
     *
     * @param year the value used to set the <code>YEAR</code> calendar field.
     * @param month the value used to set the <code>MONTH</code> calendar field.
     * Month value is 0-based. e.g., 0 for January.
     * @param date the value used to set the <code>DAY_OF_MONTH</code> calendar field.
     * @param hourOfDay the value used to set the <code>HOUR_OF_DAY</code> calendar field.
     * @param minute the value used to set the <code>MINUTE</code> calendar field.
     * @param second the value used to set the <code>SECOND</code> calendar field.
     * @see #set(int,int)
     * @see #set(int,int,int)
     * @see #set(int,int,int,int,int)
     */
    public final void set(int year, int month, int date, int hourOfDay, int minute,
                          int second)
    {
        set(YEAR, year);
        set(MONTH, month);
        set(DATE, date);
        set(HOUR_OF_DAY, hourOfDay);
        set(MINUTE, minute);
        set(SECOND, second);
    }

看上面代码中飘红的部分，一月份是从0开始的~显而易见，需要将月份-1