Volley使用singleton将访问令牌附加到evey请求

Question

我正在做以下完美的工作

    //else proceed with the checks
    JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(
            Request.Method.GET,
            checkauthurl,
            null,
            new Response.Listener<JSONObject>() {
                @Override
                public void onResponse(String response) { 
                         //do stuff here
                }
            },
            new Response.ErrorListener() {
                @Override
                public void onErrorResponse(VolleyError error) {
                   // do stuff here
                }
            }) {
                @Override
                public Map<String, String> getHeaders() throws AuthFailureError {
                    HashMap<String, String> headers = new HashMap<String, String> ();
                    TokenService tokenservice = new TokenService(ctx);
                    String accesstoken = tokenservice.getToken(ApiHelper.ACCESS_TOKEN_SHARED_PREF);
                    headers.put("Authorization", "Bearer " + accesstoken);

                    return headers;
              }
    };

    // Access the RequestQueue through your singleton class.
    ApiSingleton strngle = new ApiSingleton(ctx);
    strngle.addToRequestQueue(jsonObjectRequest);

对于每个请求,我都要添加请求标头.如何直接在单例中设置请求标头.

这是我的单身人士

private static ApiSingleton mInstance;
private RequestQueue mRequestQueue;
public static Context mCtx;
private ImageLoader mImageLoader;

public ApiSingleton(Context context) {
    mCtx = context;
    mRequestQueue = getRequestQueue();
    //do stuff
}

public RequestQueue getRequestQueue() {
    if (mRequestQueue == null) {
        // getApplicationContext() is key, it keeps you from leaking the
        // Activity or BroadcastReceiver if someone passes one in.
        mRequestQueue = Volley.newRequestQueue(mCtx.getApplicationContext());
    }
    return mRequestQueue;
}

在每个请求中附加承载令牌时,如何避免上述代码重复？

Answer 1

创建一个 AppController.java 文件并在清单标记中将此文件名指定为 android:app。

public class AppController extends Application {

    public static final String TAG = AppController.class.getSimpleName();
    private RequestQueue mRequestQueue;
    private static AppController mInstance;
    private ImageLoader mImageLoader;

    @Override
    public void onCreate() {
        super.onCreate();
        mInstance = this;
    }
    public static synchronized AppController getInstance() {
        return mInstance;
    }

    public RequestQueue getRequestQueue() {
        if (mRequestQueue == null) {
            mRequestQueue = Volley.newRequestQueue(getApplicationContext());
        }
        return mRequestQueue;
    }

    public ImageLoader getImageLoader() {
        getRequestQueue();
        if (mImageLoader == null) {
            mImageLoader = new ImageLoader(this.mRequestQueue, new LruBitmapCache());
        }
        return this.mImageLoader;
    }
    public <T> void addToRequestQueue(Request<T> req, String tag) {
        req.setTag(TextUtils.isEmpty(tag) ? TAG : tag);
        getRequestQueue().add(req);
    }
    public <T> void addToRequestQueue(Request<T> req) {
        req.setTag(TAG);
        getRequestQueue().add(req);
    }
    public void cancelPendingRequests(Object tag) {
        if (mRequestQueue != null) {
            mRequestQueue.cancelAll(tag);
        }
    }
}

编写网络代码

 StringRequest strReq = new StringRequest(Request.Method.POST, AppConfig.URL_BUYER_LOGIN, 
new Response.Listener<String>() {

                @Override
                public void onResponse(String response) {

                }
            }, new Response.ErrorListener() {

                @Override
                public void onErrorResponse(VolleyError error) {

                }
            }) {
                @Override
                protected Map<String, String> getParams() {

                }
            };
            // Adding request to request queue
            AppController.getInstance().addToRequestQueue(strReq, tag_string_req);
        }