Collections.sort()排序和map排序方法

Collections.sort()排序和map排序方法:

  /**
     * map排序
     * @param rankTimesMap
     * @return
     */
    private HashMap<String, Integer> hashMapSort(Map<String, Integer> rankTimesMap, final Map<String, Integer> rankCountMap){
        // 按顺序保存rankTimesMap中的元素,使用LinkedList类型
        List<Map.Entry<String, Integer>> keyList = new LinkedList<Map.Entry<String, Integer>>(rankTimesMap.entrySet());
        // 按照上榜次数降序的规则排序
        Collections.sort(keyList, new Comparator<Map.Entry<String, Integer>>() {
            @Override
            public int compare(Map.Entry<String, Integer> o1, Map.Entry<String, Integer> o2) {
                if (o2.getValue().compareTo(o1.getValue()) > 0){
                    return 1;
                } else if(o2.getValue().compareTo(o1.getValue()) < 0){
                    return -1;
                }  else {
                    // 如果上榜次数相同,按照名次之和升序排序
                    Integer rankCountO1 = rankCountMap.get(o1.getKey());
                    Integer rankCountO2 = rankCountMap.get(o2.getKey());
                    if (rankCountO1.compareTo(rankCountO2) > 0) {
                        return 1;
                    } else if (rankCountO1.compareTo(rankCountO2) < 0) {
                        return -1;
                    } else {
                        return 0;
                    }
                }
            }

        });
        // 将LinkedList按照排序好的结果,存入到HashMap中
        HashMap<String,Integer> result = new LinkedHashMap<>();
        for(Map.Entry<String, Integer> entry : keyList){
            result.put(entry.getKey(), entry.getValue());
        }
        return result;
    }
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原文地址:https://www.cnblogs.com/stromgao/p/12185697.html