-1
我有以下的單身網絡單與Android的改造 - 空引用異常
public class APIShared {
public String API_BASE_URL = "http://url.com/";
public static APIShared instance;
public APIManager client;
private Context context;
private Retrofit retrofit;
private APIShared (Context context) {
this.context = context;
retrofit = new Retrofit.Builder()
.baseUrl(API_BASE_URL)
.addConverterFactory(GsonConverterFactory.create())
.build();
client = retrofit.create(APIManager.class);
}
public static APIShared init(Context context){
if (null == instance){
instance = new APIShared(context);
}
return instance;
}
}
,並在我的MainActivity
內onCreate
我打電話
Call<List<Category>> call = APIShared.instance.client.categories();
當我啓動應用程序,我得到
java.lang.NullPointerException:嘗試從字段'com.example.me.fooder.APIManager com.examp le.me.fooder.APIShared.client'上的空對象引用
我在做什麼錯?