public class MapSort {
public static void main(String[] args) throws UnknownHostException, SocketException {
List<Map<String, Object>> listResult = new ArrayList<Map<String, Object>>();
Map<String, Object> map1 = new LinkedHashMap<String, Object>();
map1.put("count", 2);
map1.put("name", "abc");
map1.put("key", "acv");
listResult.add(map1);
Map<String, Object> map2 = new LinkedHashMap<String, Object>();
map2.put("count", 3);
map2.put("name", "bbc");
map2.put("key", "bcv");
listResult.add(map2);
Map<String, Object> map3 = new LinkedHashMap<String, Object>();
map3.put("count", 1);
map3.put("name", "cbc");
map3.put("key", "ccv");
listResult.add(map3);
Map<String, Object> map4 = new LinkedHashMap<String, Object>();
map4.put("count", 4);
map4.put("name", "cbc");
map4.put("key", "ccv");
listResult.add(map4);
System.out.println("排序前:");
for (Map<String, Object> map : listResult) {
System.out.println("count:"+map.get("count")+" name:"+map.get("name")+" key:"+map.get("key"));
}
Collections.sort(listResult, new MapComparatorDesc());
System.out.println("降序:");
for (Map<String, Object> map : listResult) {
System.out.println("count:"+map.get("count")+" name:"+map.get("name")+" key:"+map.get("key"));
}
Collections.sort(listResult, new MapComparatorAsc());
System.out.println("升序:");
for (Map<String, Object> map : listResult) {
System.out.println("count:"+map.get("count")+" name:"+map.get("name")+" key:"+map.get("key"));
}
}
static class MapComparatorDesc implements Comparator<Map<String, Object>> {
@Override
public int compare(Map<String, Object> m1, Map<String, Object> m2) {
Integer v1 = Integer.valueOf(m1.get("count").toString());
Integer v2 = Integer.valueOf(m2.get("count").toString());
if (v2 != null) {
return v2.compareTo(v1);
}
return 0;
}
}
static class MapComparatorAsc implements Comparator<Map<String, Object>> {
@Override
public int compare(Map<String, Object> m1, Map<String, Object> m2) {
Integer v1 = Integer.valueOf(m1.get("count").toString());
Integer v2 = Integer.valueOf(m2.get("count").toString());
if(v1 != null){
return v1.compareTo(v2);
}
return 0;
}
}
}
/*运行结果
排序前:
count:2 name:abc key:acv
count:3 name:bbc key:bcv
count:1 name:cbc key:ccv
count:4 name:cbc key:ccv
降序:
count:4 name:cbc key:ccv
count:3 name:bbc key:bcv
count:2 name:abc key:acv
count:1 name:cbc key:ccv
升序:
count:1 name:cbc key:ccv
count:2 name:abc key:acv
count:3 name:bbc key:bcv
count:4 name:cbc key:ccv
*/