如何在数组中存储多个数据类型？

Question

我正在寻找类似于Array的东西,但它需要存储多种数据类型.Oracle Java教程说:"数组是一个容器对象,它包含固定数量的单一类型的值." 因此,如果我不能将数组用于多种类型,我该使用什么？

我有这个代码,一次只向地图添加一个标记,因为它在每个循环上写入我的lat和long值,并且只将最后一个传递给onPostExecute.所以我需要像数组一样传递多种形式的联系信息.即我从每个JSON字符串中提取位置,但我需要从该后台线程中拉出并将名称和电话号码传递给UI.

try {

    String apples = endpoint.listContactInfo().execute().toString();

    JSONObject jObject = new JSONObject(apples);

    JSONArray jsonArr = jObject.getJSONArray("items");

     for(int i =0 ; i<jsonArr.length() ;i++ ){
         JSONObject jsonObj1 = jsonArr.getJSONObject(i);


                    // Storing each json item in variable
                    String id = jsonObj1.getString(TAG_ID);
                    String nameFirst1 = jsonObj1.getString(TAG_FIRSTNAME);
                    String nameLast1 = jsonObj1.getString(TAG_LASTNAME);
                    String emailAddress1 = jsonObj1.getString(TAG_EMAIL);
                    String streetAddress1 = jsonObj1.getString(TAG_ADDRESS);
                    String phone1 = jsonObj1.getString(TAG_PHONE);

                    //test to see if made it to string
                    Log.d("YOUR_TAG", "First Name: " + nameFirst1 + " Last Name: " + nameLast1);

                       address = coder.getFromLocationName(streetAddress1,5);

                        Address location1 = address.get(0);

                        // SET LAT LNG VALUES FOR MARKER POINT

                     lati = location1.getLatitude();
                         longi = location1.getLongitude();



                         Log.d("Location", "Location:" + lati + " " +  longi);


     }

    } catch (IOException e) {
    e.printStackTrace();
  } catch (JSONException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}
      return (long) 0;


    }
         // ADD MARKER TO MAP UI
    protected void onPostExecute(Long result) {
        mMap.addMarker(new MarkerOptions()
        .position(new LatLng(lati, longi))
         .title("Hello world"));
    }  

Answer 1

You can use an ArrayList.

ArrayList<Object> listOfObjects = new ArrayList<Object>();

And then add items to it.

listOfObjects.add("1");
listOfObjects.add(someObject);

Or create your own object that encapsulates all the field that you require like

public class LocationData {
   private double lat;
   private double longitude;

   public LocationData(double lat, double longitude) {
       this.lat = lat;
       this.longitude = longitude;
   }
   //getters
   //setters
}

and then add your lat/long pairs to an ArrayList of type LocationData

ArrayList<LocationData> listOfObjects = new ArrayList<LocationData>();

listOfObjects.add(new LocationData(lat, longitude));

Answer 2

您可以创建自定义类的数组.

public class YourCustomClass {

     String id;
     String name;
     double longitude;
     // and many more fields ...

    public YourCustomClass() {  // constructor 

    }

    public void setID(String id) {
        this.id = id;
    }

    public String getID() {
        return id;
    }

    // and many more getter and setter methods ...
}

在您的自定义类中,您可以拥有任意数量的字段,您可以在其中存储数据,然后使用它:

// with array 
YourCustomClass [] array = new YourCustomClass[10];
array[0] = new YourCustomClass();
array[0].setID("yourid");

String id = array[0].getID();

// with arraylist
ArrayList<YourCustomClass> arraylist = new ArrayList<YourCustomClass>();
arraylist.add(new YourCustomObject());
arraylist.get(0).setID("yourid");

String id = arraylist.get(0).getID();

您还可以让AsyncTasks doInBackground(...)方法返回您的Custom-class:

protected void onPostExecute(YourCustomClass result) {
 // do stuff...
}

或者一个数组:

protected void onPostExecute(YourCustomClass [] result) {
 // do stuff...
}

或者一个ArrayList:

protected void onPostExecute(ArrayList<YourCustomClass> result) {
 // do stuff...
}

编辑:当然,您也可以创建自定义对象的ArrayList.

Answer 3

您应该考虑使用类型安全的异构容器模式。

数据存储在 a 中Map<Key<?>, Object>，对地图的访问隐藏在通用方法后面，这些方法会自动转换返回值。

public <T> T getObjectByKey(Key<T> key)
  return (T) map.get(key);

对于put.