从其他类访问HashMap

将HashMap创建为实例变量，并提供一种将其访问类API的方法：

public class DataStorage {    private HashMap<String, Integer> people = new HashMap<String, Integer>();    public HashMap<String, Integer> getPeopleMap() {         return people;    }}public class AnotherClass {      DataStorage x = new DataStorage();      private void someMethod() {HashMap<String, Integer> people = x.getPeopleMap();//work with your map here...      }  }