我有一个函数 searchForTrips()，它发送 API 请求并按以下方式获取一些响应。

private void searchForTrips(){

    int departurePortId = PORT_ID_LIST.get(departurePort);
    int returnPortId = PORT_ID_LIST.get(returnPort);
    int pax= Integer.parseInt(noOfPassengers);
    String departureDatePARSED = DEPARTURE_DATE_VALUES.get(departureDate);
    String returnDatePARSED = RETURN_DATE_VALUES.get(departureDate);

    Call<TripSearchResponse> call = apiService.searchAvailableTrips(TripType,departurePortId,returnPortId,departureDatePARSED,returnDatePARSED,pax);
    call.enqueue(new Callback<TripSearchResponse>() {
        @Override
        public void onResponse(Call<TripSearchResponse> call, Response<TripSearchResponse> response) {
            int statusCode = response.code();
            switch(statusCode){
                case 200:

                default:
                    Snackbar.make(findViewById(android.R.id.content),"Error loading data. Network Error.", Snackbar.LENGTH_LONG).show();
                break;
            }
        }
        @Override
        public void onFailure(Call<TripSearchResponse> call, Throwable t) {
            Log.i(TAG, t.getMessage());
            Snackbar.make(findViewById(android.R.id.content),"Error loading data. Network Error.", Snackbar.LENGTH_LONG).show();
        }
    });

}

目的是使此回调函数可重用，以便我可以从多个 Activity 中调用它并根据需要获取请求的数据。实现这一点的最佳方法是什么？

最佳答案

尝试这种方式，它的动态方式和易于使用:

创建 Retforit 接口(interface):

public interface ApiEndpointInterface {

    @Headers("Content-Type: application/json")
    @POST(Constants.SERVICE_SEARCH_TRIP)
    Call<JsonObject> searchForTrip(@Body TripRequest objTripRequest);

}

创建改造类:

public class AppEndPoint {

    private static Retrofit objRetrofit;

    public static ApiEndpointInterface getClient() {
        if (objRetrofit == null){
            objRetrofit = new Retrofit.Builder()
                    .baseUrl(Constants.SERVER_URL)
                    .addConverterFactory(GsonConverterFactory.create())
                    .build();
        }
        return objRetrofit.create(ApiEndpointInterface.class);
    }
}

创建这个辅助类/接口(interface)来保存网络服务回调:

public enum ResponseState {
    SUCCESS,
    FAILURE,
    NO_CONNECTION
}

public enum RequestType {
    SEARCH_FOR_TRIP // add name for each web service
}


public class Response {
    public ResponseState state;
    public boolean hasError;
    public RequestType requestType;
    public JsonObject result;
}

public interface RestRequestInterface {
    void Response(Response response);
    Context getContext();
}

public class ResponseHolder { used to hold the Json response could be changed as your response

    @SerializedName("is_successful")
    @Expose
    private boolean isSuccessful;

    @SerializedName("error_message")
    @Expose
    private String errorMessage;


    public boolean isSuccessful() {
        return isSuccessful;
    }

    public void setSuccessful(boolean successful) {
        isSuccessful = successful;
    }

    public String getErrorMessage() {
        return errorMessage;
    }

    public void setErrorMessage(String errorMessage) {
        this.errorMessage = errorMessage;
    }
}

public class AppClient {
    private static ApiEndpointInterface objApiEndpointInterface;
    private static Response objResponse;
    private static Call<JsonObject> objCall;


    // implement new method like below for each new web service
    public static void searchForTrip(TripRequest objTripRequest, RestRequestInterface objRestRequestInterface) {
        objResponse = new Response();
        objResponse.state = ResponseState.FAILURE;
        objResponse.hasError = true;
        objResponse.requestType = RequestType.SEARCH_FOR_TRIP; // set type of the service from helper interface

        objApiEndpointInterface = AppEndPoint.getClient();
        objCall = objApiEndpointInterface.searchForTrip(objTripRequest);
        handleCallBack(objRestRequestInterface);
    }

    private static void handleCallBack(final RestRequestInterface objRestRequestInterface) {
        objCall.enqueue(new Callback<JsonObject>() {
            @Override
            public void onResponse(Call<JsonObject> call, retrofit2.Response<JsonObject> response) {
                try {
                    ResponseHolder objResponseHolder = new Gson().fromJson(response.body(), ResponseHolder.class);
                    if (objResponseHolder.isSuccessful()) {
                        objResponse.state = ResponseState.SUCCESS;
                        objResponse.hasError = false;
                        objResponse.result = response.body();
                    } else {
                        objResponse.errorMessage = objResponseHolder.getErrorMessage();
                    }
                    objRestRequestInterface.Response(objResponse);

                } catch (Exception objException) {
                    objResponse.errorMessage = objRestRequestInterface.getContext().getString(R.string.server_error);
                    objRestRequestInterface.Response(objResponse);
                }
            }

            @Override
            public void onFailure(Call<JsonObject> call, Throwable objThrowable) {
                String errorMessage = "";
                if (objThrowable instanceof IOException) {
                    errorMessage = objRestRequestInterface.getContext().getString(R.string.no_connection_error);
                } else {
                    errorMessage = objRestRequestInterface.getContext().getString(R.string.server_error);
                }
                objResponse.errorMessage = errorMessage;
                objRestRequestInterface.Response(objResponse);
            }
        });
    }
}

然后转到您的 fragment Activity 并像这样进行调用:

public class MainActivity extends AppCompatActivity implements RestRequestInterface {

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

        // initialize ids

        // prepare to call web service

        // 1.Initialize your object to be sent over web service
        TripRequest objTripRequest = new TripRequest();
        objTripRequest.id = 1;

        // 2.Show loader

        // 3.Make the call
        AppClient.searchForTrip(objTripRequest, this);
    }

    @Override
    public void Response(Response response) {
        // hide loader
        try {
            if (response.state == ResponseState.SUCCESS && !response.hasError) {
                // check the type of web service
                if (response.requestType == RequestType.SEARCH_FOR_TRIP) {
                    // acces the return here from  response.result
                }
            } else {
                String errorMsg = response.hasError ? response.errorMessage : getString(R.string.no_connection_error);
                // show the error to the user
            }
        } catch (Exception objException) {
            // show the error to the user
        }
    }

    @Override
    public Context getContext() {
        // do not forgit set the context here
        // if fragment replace with getAcitvity();
        return this;
    }
}

关于java - 在多项 Activity 中使用改造响应的最佳方式，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/47902000/