从不同的类访问HashMap

Question

我的课程中有一个名为DataStorage的hashmap:

HashMap<String, Integer> people = new HashMap<String, Integer>();

people.put("bob", 2);
people.put("susan", 5);

如何在不同的类中访问此HashMap中的数据？

Answer 1

将HashMap创建为实例变量,并提供一种方法将其访问到您的类API中:

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...
      }  
}