對Map裡面的key和value按字母排序
阿新 • • 發佈:2019-02-03
import java.util.ArrayList; import java.util.Collections; import java.util.Comparator; import java.util.HashMap; import java.util.List; import java.util.Map; public class Test { public static void main(String[] args) { Map<String, Integer> map = new HashMap<String, Integer>(); map.put("Total Memory", 2); map.put("Max Memory", 1); map.put("Free Memory", 1); map.put("Actual Free", 3); List<Map.Entry<String, Integer>> infoIds = new ArrayList<Map.Entry<String, Integer>>(map.entrySet()); //排序方法 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()); } }); //排序後 for (int i = 0; i < infoIds.size(); i++) { String id = infoIds.get(i).toString(); System.out.println(id); } //排序後 for(Map.Entry<String, Integer> m : infoIds){ System.out.println(m.getKey()+":"+ m.getValue()); } } }