Retrofit Android从REST API获取日期无法正常工作

Question

I have a rest API on spring. I can get data from url: localhost:8080/all I created class:

public class DataAPI {
    private static final String CLASS_TAG = "DataAPI";
    RestAdapter retrofit;
    MyWebService myWebService;
    private List<Teacher> list;


    public DataAPI() {
        String url = "http://10.101.12.31:8080/";
        retrofit = new RestAdapter.Builder()
                .setEndpoint(url)
                .build();
        myWebService = retrofit.create(MyWebService.class);
    }

    @RequiresApi(api = Build.VERSION_CODES.N)
    public List<Department> getAllDepartments() {
        try {
            myWebService.getAllTeacher(new Callback<List<Teacher>>() {

                @Override
                public void success(List<Teacher> data, Response response) {
                    Log.d(CLASS_TAG, data.toString());
//                  data.stream().forEach(System.out::println);
                    list= data;

                }

                @Override
                public void failure(RetrofitError error) {

                }
            });

        } catch (Exception e) {
            Log.d(CLASS_TAG, e.toString());
        }

        return this.departmentList;
    }

MyWebService:

public interface MyWebService {
    @GET("/all")
    void getAllDepartments(Callback<List<Teacher>> pResponse);

MainActivity:

public class MainActivity extends AppCompatActivity {
    private static final String CLASS_TAG = "MainActivity";

    TextView textView;
    DataAPI dataAPI;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        dataAPI = new DataAPI();
        setContentView(R.layout.activity_main);

        textView = findViewById(R.id.textView);


        findViewById(R.id.button_get).setOnClickListener(new View.OnClickListener() {


            @RequiresApi(api = Build.VERSION_CODES.N)
            @Override
            public void onClick(View v) {
                textView.setText("");


                List<Teacher> list = dataAPI.getAllDepartments();
                System.out.println(list == null);
                if (list != null){
                    list.stream().forEach(x -> textView.setText(textView.getText() + "\n" + x.toString()));
                }
            }
        });

I have a button on my application. When I first time click on it, nothing change, but when i click second time, data are loading. When I paste all code form DataAPI to method onClick,data are loading at first time.

Answer 1

use interface to get data to called activity like below, first write interface,

public class APICallBack {

public interface GetResponseCallback{
    void onSuccess(yourresponsetype response);
    void onFailed();
}
}

implement this interface in your MainActivity . when you call dataAPI.getAllDepartments();

pass the interface to your DataAPI class.

 public List<Department> getAllDepartments(final APICallback.GetResponseCallback callback){

            @Override
            public void success(List<Teacher> data, Response response) {
                Log.d(CLASS_TAG, data.toString());
//                  data.stream().forEach(System.out::println);
                list= data;
              callback.onSuccess(response);
            }

}

Answer 2

If one can use that RestAdapter.Builder with GSON , one can define a date-format for the parser:

Gson gson = new GsonBuilder()
    .setDateFormat(API_DATE_FORMAT)
    .create();

Retrofit retrofit = new retrofit2.Retrofit.Builder()
    .addConverterFactory(GsonConverterFactory.create(gson))
    .baseUrl(API_BASE_URL)
    .build();