java - Java排序List时出现错误 "no suitable method found"

Question

我正在尝试在转换 String 的 List 后对 Integer 的 List 进行排序转换为Integer List。它给了我这个错误:

no suitable method found for sort(List,StringToInteger.CustomComparator)

这是我的代码:

public class StringToInteger {

    public static void main(String args) {
        List<String> strList = new ArrayList<String>();
        strList.add("34");
        strList.add("14");
        strList.add("42");
        strList.add("24");

        List<String> resultList = getIntegerArray(strList);
        System.out.println("before sorting"+resultList);
        Collections.sort(resultList, new CustomComparator());
        System.out.println("after sorting"+resultList);
    }

    private static List<Integer> getIntegerArray(List<String> stringArray) {
        List<Integer> result = new ArrayList<Integer>();
        for(String stringValue : stringArray) {
            try {
                //Convert String to Integer, and store it into integer array list.
                result.add(Integer.parseInt(stringValue));
            } catch(NumberFormatException nfe) {
                //System.out.println("Could not parse " + nfe);
                Log.w("NumberFormat", "Parsing failed! " + stringValue + " can not be an integer");
            } 
        }       
        return result;
    }

    class CustomComparator implements Comparator<List<Integer>> {
        @Override
        public int compare(List<Integer> o1, List<Integer> o2) {
            return o1.get(1).compareTo(o2.get(1));
        }
    }
}

Answer 1

您正在比较 CustomComperator 中的整数列表，而您应该比较整数。您还可以使用

对列表进行排序

Collections.sort(resultList);

或

Collections.reverse(resultList);