先将 Map 中的 key 和 value 全部取出来封装成 JavaBea 数组,再将这个数组排序,
排序完成后,重新写回 Map 中,写回时采用 LinkedHashMap 可以保证迭代的顺序。
下面的代码可以参考一下:
import java.util.ArrayList; import java.util.Collections; import java.util.Comparator; import java.util.HashMap; import java.util.Iterator; import java.util.LinkedHashMap; 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("ee", 3); map.put("b", 1); map.put("d", 2); map.put("eee", 3); map.put("A", 1); map.put("K", 2); map.put("ade", 1); map.put("c", 2); map.put("aee", 3); map.put("a", 1); map.put("faed", 2); map.put("bdd", 1); map.put("qec", 2); map.put("eade", 3); map.put("Aadf", 1); map.put("Kqe", 2); Map<String, Integer> sortMap = new Test().sortMap(map); for(Map.Entry<String, Integer> entry : sortMap.entrySet()) { System.out.println(entry.getKey() + " --> " + entry.getValue()); } } public <K, V extends Number> Map<String, V> sortMap(Map<String, V> map) { class MyMap<M, N> { private M key; private N value; private M getKey() { return key; } private void setKey(M key) { this.key = key; } private N getValue() { return value; } private void setValue(N value) { this.value = value; } } List<MyMap<String, V>> list = new ArrayList<MyMap<String, V>>(); for (Iterator<String> i = map.keySet().iterator(); i.hasNext(); ) { MyMap<String, V> my = new MyMap<String, V>(); String key = i.next(); my.setKey(key); my.setValue(map.get(key)); list.add(my); } Collections.sort(list, new Comparator<MyMap<String, V>>() { public int compare(MyMap<String, V> o1, MyMap<String, V> o2) { if(o1.getValue() == o2.getValue()) { return o1.getKey().compareTo(o2.getKey()); }else{ return (int)(o1.getValue().doubleValue() - o2.getValue().doubleValue()); } } }); Map<String, V> sortMap = new LinkedHashMap<String, V>(); for(int i = 0, k = list.size(); i < k; i++) { MyMap<String, V> my = list.get(i); sortMap.put(my.getKey(), my.getValue()); } return sortMap; } }
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
参考: http://bbs.csdn.net/topics/230054066
http://www.cnblogs.com/lovebread/archive/2009/11/23/1609121.html