TreeMap按照value进行排序
public class MyTreeMap {
/**
* @param args
*/
public static void main(String[] args) {
Map<String, Integer> map = new TreeMap<String, Integer>();
map.put("c", 2);
map.put("ad", 1);
map.put("bc", 1);
map.put("abc", 3);
List<Map.Entry<String, Integer>> treeMapList =
new ArrayList<Map.Entry<String, Integer>>(map.entrySet());
//排序前
System.out.println("排序前------------------");
for (int i = 0; i < treeMapList.size(); i++) {
String id = treeMapList.get(i).toString();
System.out.println(id);
}
//通过key倒序排序
Collections.sort(treeMapList, new Comparator<Map.Entry<String, Integer>>() {
public int compare(Map.Entry<String, Integer> o1, Map.Entry<String, Integer> o2) {
return (o2.getKey()).toString().compareTo(o1.getKey());
}
});
System.out.println("key倒序排列------------------");
for (int i = 0; i < treeMapList.size(); i++) {
String id = treeMapList.get(i).toString();
System.out.println(id);
}
//通过value倒序排序
Collections.sort(treeMapList, new Comparator<Map.Entry<String, Integer>>() {
public int compare(Map.Entry<String, Integer> o1, Map.Entry<String, Integer> o2) {
return (o2.getValue() - o1.getValue());
}
});
System.out.println("value倒序排列------------------");
for (int i = 0; i < treeMapList.size(); i++) {
String id = treeMapList.get(i).toString();
System.out.println(id);
}
}