src/org/nutz/lang/Times.java
public static int yearDiff(String before, String after) {
        Date beforeDay = parseq(DF_DATE, before);
        Date afterDay = parseq(DF_DATE, after);
        return getYear(afterDay) - getYear(beforeDay);
    }
public static int yearDiff(String before, String after) {
        Date beforeDay = parseq(DF_DATE, before);
        Date afterDay = parseq(DF_DATE, after);
        return getYear(afterDay) - getYear(beforeDay);
    }
比较两个日期的年差

@param before
前一个日期,格式yyyy-MM-dd
@param after
后一个日期,格式yyyy-MM-dd
@return 年份差值