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：
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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
[Java]HashMap的两种排序方式,布布扣,bubuko.com
原文：http://www.cnblogs.com/hqbhonker/p/3757864.html