java - 对列表中的 MMM-yyyy 进行排序，而不转换为日期

Question

如何在不将字符串转换为 Date 对象的情况下对 MonthYear 列表进行排序？我无法在这里应用逻辑。

public class SortDates {

    public static void main(String[] args) {

        String[] monthName = { "JAN", "FEB", "MAR", "APR", "MAY", "JUN", "JUL",
                "AUG", "SEP", "OCT", "NOV", "DEC" };

        List<String> monthYear = new ArrayList<String>();

        monthYear.add("JAN-1999");
        monthYear.add("JUN-2009");
        monthYear.add("MAR-2003");
        monthYear.add("JAN-1998");
        monthYear.add("NOV-2013");

    }

}

Answer 1

我首先会在枚举中描述月份:

enum Month{ JAN, FEB, MAR, APR, MAY, JUN, JUL, AUG, SEP, OCT, NOV, DEC };

然后您就可以轻松实现自己的比较器:

public static class MyComparator implements Comparator<String>{
  @Override
  public int compare(String s1, String s2) {

    //If s1="JAN-1999", parts1[0]="JAN", parts1[1]="1999"
    String[] parts1=s1.split("-");
    //Month.valueOf("JAN") converts "JAN" to Month.JAN
    int m1 = Month.valueOf(parts1[0]).ordinal();
    int year1 = Integer.valueOf(parts1[1]);

    String[] parts2=s2.split("-");
    int m2 = Month.valueOf(parts2[0]).ordinal();
    int year2 = Integer.valueOf(parts2[1]);

    return ...//Here, compare year1 to year2 and if necessary, m1 and m2
    //You can also return (100*year2+m2) - (100*year1+m1)
  }
}

然后用它来排序:

Collections.sort(monthYear, new MyComparator());