使用Retrofit调用API

Question

我是ANdroid的新手，这是我对Retrofit的第一次测试。我使用Retofit来调用API，如下所示。 我的问题是，当我运行应用程序时，我得到空白屏幕。我想在列表中显示音频文件，然后播放选定的音频。我的api看起来像这样：

我正在使用Retrofit来调用这个Api。这就是Restclient和RestInterface我使用`

public class RestClient {
private static RestInterface mInterface;

public static RestInterface getClient() {
    if (mInterface == null) {

        OkHttpClient okClient = new OkHttpClient();
        okClient.interceptors().add(new Interceptor() {
            @Override
            public Response intercept(Chain chain) throws IOException {
                Response response = chain.proceed(chain.request());
                return response;
            }
        });
        Retrofit client = new Retrofit.Builder()
                .baseUrl(BASE_URL)
                .addConverter(String.class, new ToStringConverter())
                .client(okClient)
                .addConverterFactory(GsonConverterFactory.create())
                .build();
        mInterface = client.create(RestInterface.class);
    }
    return mInterface;
}

public interface RestInterface {
    @GET("/bins/15oqx")
    Call<AudioReturn> audioReturn();

}

使用的适配器就像这个`

public class AudioAdapter extends 
RecyclerView.Adapter<AudioAdapter.AudioViewHolder> {
Context mContext;
private ArrayList<AudioReturn.data> mAudioReturn = new ArrayList<>();

public AudioAdapter(Context context, ArrayList<AudioReturn.data> list) {
    mContext = context;
    mAudioReturn = list;
}
@Override
public int getItemCount() {
    return mAudioReturn.size();
}
@Override
public void onBindViewHolder(AudioViewHolder holder, int position) {
    AudioReturn.data current = mAudioReturn.get(position);

    holder.track.setText(current.getTrack());
    holder.trackname.setText(mAudioReturn.get(position).getTrackname());
}
@Override
public AudioAdapter.AudioViewHolder onCreateViewHolder(ViewGroup viewGroup, int position) {
    View itemView = LayoutInflater.
            from(viewGroup.getContext()).
            inflate(R.layout.view_audio_files, viewGroup, false);
    return new AudioAdapter.AudioViewHolder(itemView);
}
public void updateData(ArrayList<AudioReturn.data> datas) {
    this.mAudioReturn = datas;
    notifyDataSetChanged();
}
public class AudioViewHolder extends RecyclerView.ViewHolder {
    @Bind(R.id.view_audio_file_Track_Number)
    TextView track;
    @Bind(R.id.view_audio_file_Audio_Name)
    TextView trackname;
    public AudioViewHolder(View itemView) {
        super(itemView);
        ButterKnife.bind(this, itemView);
    }
}

和Pojo是`public class AudioReturn {     ArrayList dataList = new ArrayList＆lt;＆gt;（）;

public class data {
    String track, trackname;

    public data(String track, String trackname) {
        this.track = track;
        this.trackname = trackname;
    }

    public String getTrack() {
        return track;
    }

    public String getTrackname() {
        return trackname;
    }
}
public AudioReturn(ArrayList<data> dataList) {
    this.dataList = dataList;
}

   public ArrayList<data> getDataList() {
    return dataList;
}

我得到的结果是空白的。我打电话来自ACtivity：

    AudioAdapter mAudioAdapter = new AudioAdapter(this, datas);
    mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
    mRecyclerView.setHasFixedSize(true);
    mRecyclerView.setAdapter(mAudioAdapter);

    RestClient.RestInterface restInterface = RestClient.getClient();

    Call<AudioReturn> audioReturnCall = restInterface.audioReturn();
    audioReturnCall.enqueue(new Callback<AudioReturn>() {
        @Override
        public void onResponse(Response<AudioReturn> response) {
            datas = response.body().getDataList();
            mAudioAdapter.updateData(datas);
            Toast.makeText(AudioActivity.this, "Success", Toast.LENGTH_SHORT).show();

        }

        @Override
        public void onFailure(Throwable t) {
            Toast.makeText(AudioActivity.this, "Failure", Toast.LENGTH_SHORT).show();
        }
    });
}`

Answer 1

在你的json中，曲目列表被称为data。 但是在您的班级AudioReturn中，您将其称为dataList，将其更改为data，它应该有效。

修改

将您的数据类替换为：

public class Data {
    // The fields names should be exactly equal to the one of the json
    private String track;
    private String trackName;

    // Retrofit needs a default constructor
    public Data() {
    }

    public Data(String track, String trackName) {
        this.track = track;
        this.trackName = trackName;
    }

    // Retrofit needs getters and setters for each field
    public String getTrack() {
        return track;
    }

    public void setTrack(String track) {
        this.track = track;
    }

    public String getTrackName() {
        return trackName;
    }

    public void setTrackName(String trackName) {
        this.trackName = trackName;
    }
}

您的AudioReturn课程：

public class AudioReturn {
    // The fields names should be exactly equal to the one of the json
    private List<Data> data;

    // Retrofit needs a default constructor
    public AudioReturn() {
    }

    public AudioReturn(List<Data> data) {
        this.data = data;
    }

    // Retrofit needs getters and setters for each field
    public List<Data> getData() {
        return data;
    }

    public void setData(List<Data> data) {
        this.data = data;
    }
}

Answer 2

                **Retrofit to calling api**




                *****ApiInterface*****

                public interface ApiInterface
                {
                    // add
                    @FormUrlEncoded
                    @POST("/login.php")
                    void login(
                            @Field("email_address") String email_address,
                            @Field("password") String password,
                            Callback<Response> user);
                //get
                @FormUrlEncoded
                    @POST("/get_followers_following_list.php")
                    void getfollowingList(
                            @Field("user_id") String user_id,
                            @Field("type") String type,
                            Callback<Response> user);
            }



        *RestClient*

        public class RestClient extends Activity
        {
            private static ApiInterface REST_CLIENT;

            static {
                setupRestClient();
            }

            private RestClient()
            {
            }

            private static void setupRestClient()
            {
                Gson gson = new GsonBuilder()
                        .registerTypeAdapterFactory(new ItemTypeAdapterFactory()) // This is the important line ;)
                        .setDateFormat("yyyy'-'MM'-'dd'T'HH':'mm':'ss'.'SSS'Z'")
                        .create();

                REST_CLIENT = buildAdapter(Constant.URL, gson).create(ApiInterface.class);
            }

            private static RestAdapter buildAdapter(String endPoint, Gson gson)
            {
                return new RestAdapter.Builder()
                        .setLogLevel(RestAdapter.LogLevel.FULL)
                        .setEndpoint(endPoint)
                        .setConverter(new GsonConverter(gson))
                        .build();
            }

            public static ApiInterface getDemo() {
                return REST_CLIENT;
            }
        }




    **// Add login** 
    login(edit_email.getText().toString(), edit_password.getText().toString());
    private void login(String email, String password) {
            if (Util.isOnline(LoginActivity.this)) {
                loginCallApi(email, password);
            } else {
                Toast.makeText(LoginActivity.this, R.string.no_internet_fount, Toast.LENGTH_SHORT).show();
            }
        }

        private void loginCallApi(String email, String password) {
            ShowProgress();
            getWindow().setFlags(WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE,
                    WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE);
            AsyncHttpClient client = new AsyncHttpClient();
            RequestParams params = new RequestParams();
            params.put("email_address", edit_email.getText().toString());
            params.put("password", edit_password.getText().toString());
            client.post(this, Constant.URL + "login.php?", params, new JsonHttpResponseHandler() {
                @Override
                public void onStart() {
                    super.onStart();
                }

                @Override
                public void onFinish() {
                    super.onFinish();
                }

                @Override
                public void onSuccess(int statusCode, cz.msebera.android.httpclient.Header[] headers, JSONObject response) {
                    super.onSuccess(statusCode, headers, response);
                    LoginResponse model = new Gson().fromJson(new String(String.valueOf(response)), LoginResponse.class);
                    Hideprogress();
                    if (model.getStatus().equalsIgnoreCase("true")) {
                        getWindow().clearFlags(WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE);
                        Toast.makeText(LoginActivity.this, "User Login Successfully", Toast.LENGTH_SHORT).show();
                        Utils.WriteSharePrefrence(LoginActivity.this, Constant.USERID, model.getData().getId());
                        String Userid = Utils.ReadSharePrefrence(LoginActivity.this, Constant.USERID);

                        Intent intent = new Intent(LoginActivity.this, MainActivity.class);
                        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK);
                        startActivity(intent);
                        finish();
                    } else {
                        getWindow().clearFlags(WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE);
                        Toast.makeText(LoginActivity.this, model.getMsg().toString(), Toast.LENGTH_SHORT).show();
                    }
                }

                @Override
                public void onFailure(int statusCode, cz.msebera.android.httpclient.Header[] headers, String responseString, Throwable throwable) {
                    super.onFailure(statusCode, headers, responseString, throwable);
                    Log.e(TAG, throwable.getMessage());
                    Hideprogress();
                    getWindow().clearFlags(WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE);
                }
            });

        }






**// get**

        if (Util.isOnline(FollowersActivity.this)) {
            getFollowersList();
        } else {
            Toast.makeText(FollowersActivity.this, R.string.no_internet_fount, Toast.LENGTH_SHORT).show();
        }

private void getFollowersList() {

        followLists = new ArrayList<>();

        progress = new ACProgressFlower.Builder(FollowersActivity.this)
                .direction(ACProgressConstant.DIRECT_CLOCKWISE)
                .themeColor(Color.WHITE)
                .fadeColor(Color.DKGRAY).build();
        progress.setCanceledOnTouchOutside(false);
        progress.show();
        RestClient.getDemo().getfollowingList(Utils.ReadSharePrefrence(FollowersActivity.this, Constant.SONG_POST_ID),
                "followers",
                new Callback<Response>() {
                    @Override
                    public void success(Response response, Response response2) {
                        progress.dismiss();
                        JSONObject jsonObject = null;
                        try {
                            jsonObject = new JSONObject(Util.getString(response.getBody().in()));
                            Gson gson = new Gson();
                            if (jsonObject.getString("status").equals("true")) {
                                GetFollowList data = gson.fromJson(jsonObject.toString(), GetFollowList.class);
                                followLists = data.getFollowers();
                                peopleLikeAdapter = new FollowersAdapter(FollowersActivity.this, followLists);
                                item_peoplelike_list.setLayoutManager(new LinearLayoutManager(FollowersActivity.this, LinearLayoutManager.VERTICAL, false));
                                item_peoplelike_list.setAdapter(peopleLikeAdapter);

                            } else {
                                progress.dismiss();
                                Toast.makeText(FollowersActivity.this, jsonObject.getString("msg"), Toast.LENGTH_SHORT).show();
                            }
                        } catch (JSONException e) {
                            e.printStackTrace();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }

                    @Override
                    public void failure(RetrofitError error) {
                        progress.dismiss();
                        Toast.makeText(FollowersActivity.this, "Something went wrong, please try again.", Toast.LENGTH_SHORT).show();
                    }
                });
    }