HashMap的两种排序方式
http://www.cnblogs.com/lovebread/archive/2009/11/23/1609121.html
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 |
Java代码 Map<String, Integer> map = new HashMap<String, Integer>(); map.put("d", 2); map.put("c", 1); map.put("b", 1); map.put("a", 3); List<Map.Entry<String, Integer>> infoIds = new ArrayList<Map.Entry<String, Integer>>(map.entrySet()); //排序前 for (int i = 0; i < infoIds.size(); i++) { String id = infoIds.get(i).toString(); System.out.println(id); } //d 2 //c 1 //b 1 //a 3 //排序 Collections.sort(infoIds, new Comparator<Map.Entry<String, Integer>>() { public int compare(Map.Entry<String, Integer> o1, Map.Entry<String, Integer> o2) { //return (o2.getValue() - o1.getValue()); return (o1.getKey()).toString().compareTo(o2.getKey()); } }); //排序后 for (int i = 0; i < infoIds.size(); i++) { String id = infoIds.get(i).toString(); System.out.println(id); } |
//根据key排序
//a 3
//b 1
//c 1
//d 2
//根据value排序
//a 3
//d 2
//b 1
//c 1
做自己喜欢做的，跟家人同等重要