持有hashset的Hashmap - 如何检索数据

Question

如何从HashMap<String,HashSet<String>> objects中获取特定属性具有相同值的所有对象的列表.String保存属性，HashSet保存属性的值列表！

Answer 1

Map<String,Set<String>> objects  = new HashMap<String,Set<String>>();
// fill it up

String needle = "value";
List<String> results = new LinkedList<String>();
for(Map.Entry<String,Set<String>> entry : objects.entry set())
{
   if(entry.getValue().contains(needle))
   {
       results.add(entry.getKey());
   }
}
return results;