Question

当我使用jsonObject请求进行网络调用时。我没有收到任何回复。我总是在我的URL之前收到request =＆lt; []的HTTP响应。我也试过这些链接，但没有任何对我有用。

当请求缓慢时，Android Volley双帖：

 package com.example.mts3.hammadnewsapp;

import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;
import android.widget.Toast;

import com.android.volley.DefaultRetryPolicy;
import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonObjectRequest;
import com.android.volley.toolbox.Volley;

import org.json.JSONObject;

import java.util.ArrayList;

public class NewsDetailsActivity extends AppCompatActivity {

    RecyclerView recyclerView;
    NewsAdapter adapter;
    ArrayList<NewsOpen> newsList =new ArrayList<>();
    Intent intent;
    TextView tv_newsheading;

    SharedPreferences sharedPreferences;
    SharedPreferences.Editor editor;
    Context context;
    String DATA_URL="http://ec2-54-147-238-136.compute-1.amazonaws.com/hmc/api/getnewsfeeds?order=asc";

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

        Toolbar toolbar =  findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        newsList = new ArrayList<>();
        recyclerView = findViewById(R.id.rv_newsdetails);
        recyclerView.setLayoutManager(new LinearLayoutManager(this));
        adapter = new NewsAdapter(this, newsList);

        String string = (String) getText(R.string.random_text);

        newsList.add(new NewsOpen(R.drawable.hdr_bg_plain, "Chief Medical Officer", "10-11-2020", string));
//        newsList.add(new NewsOpen("image!!", "Chief Medical Officer", "10-11-2020", string));

        recyclerView.setAdapter(adapter);
        /*backgroundTask.getList(new BackgroundTask.arrayCallBack() {
            @Override
            public void onSuccess(ArrayList<Contact> contacts) {
                adapter = new RecyclerAdapter(contacts);
                recyclerView.setAdapter(adapter);
            }

            @Override
            public void onFail(String msg) {
                // Do Stuff
            }
        });*/



    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_news_list, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_share) {

            //Toast.makeText(NewsDetailsActivity.this, "Share menu clicked ", Toast.LENGTH_LONG).show();
            callApi();
            return true;
        }
        if (id == R.id.action_logout) {
            sharedPreferences= PreferenceManager.getDefaultSharedPreferences(this);
            editor= sharedPreferences.edit();
            editor.putBoolean("Verified user",false);
            editor.commit();

            Toast.makeText(NewsDetailsActivity.this,"Logged out ",Toast.LENGTH_LONG).show();
            Intent intent=new Intent(NewsDetailsActivity.this,MainActivity.class);
            startActivity(intent);


            return true;
        }

        return super.onOptionsItemSelected(item);
        }

    private void callApi() {
       // new DefaultRetryPolicy(30000, 0, DefaultRetryPolicy.DEFAULT_BACKOFF_MULT);
           // int x=3;// retry count
           // DefaultRetryPolicy defaultRetryPolicy=new DefaultRetryPolicy(DefaultRetryPolicy.DEFAULT_TIMEOUT_MS*1,x,DefaultRetryPolicy.DEFAULT_BACKOFF_MULT);
        //DefaultRetryPolicy defaultRetryPolicy= new DefaultRetryPolicy(20 * 1000, 0, 1.0f);
        RequestQueue requestQueue= Volley.newRequestQueue(this);
        //System.setProperty("http.keepAlive", "false");
        JsonObjectRequest jsonObject =new JsonObjectRequest(Request.Method.GET,DATA_URL, new Response.Listener<JSONObject>() {
            @Override
            public void onResponse(JSONObject response) {
                Log.e("res",response.toString());

            }

        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {

            }

        });
        //int x=2;// retry count
        //jsonObject.setRetryPolicy(new DefaultRetryPolicy(DefaultRetryPolicy.DEFAULT_TIMEOUT_MS * 48, x, DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));

        //jsonObject.setRetryPolicy(new DefaultRetryPolicy(DefaultRetryPolicy.DEFAULT_TIMEOUT_MS * 48,0, DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));
        //jsonObject.setRetryPolicy(new DefaultRetryPolicy(0, -1, 0));
        //jsonObject.setRetryPolicy(new DefaultRetryPolicy(DefaultRetryPolicy.DEFAULT_TIMEOUT_MS * 2, DefaultRetryPolicy.DEFAULT_MAX_RETRIES, DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));
        //jsonObject.setRetryPolicy(new DefaultRetryPolicy(0,-1, DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));
        /*jsonObject.setRetryPolicy(
                new DefaultRetryPolicy(
                        500000,
                        DefaultRetryPolicy.DEFAULT_MAX_RETRIES,
                        DefaultRetryPolicy.DEFAULT_BACKOFF_MULT
                )
        );*/
        //jsonObject.setRetryPolicy(new DefaultRetryPolicy(DefaultRetryPolicy.DEFAULT_TIMEOUT_MS * 2, DefaultRetryPolicy.DEFAULT_MAX_RETRIES, DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));
        //new DefaultRetryPolicy(10000, 0, DefaultRetryPolicy.DEFAULT_BACKOFF_MULT);
        //jsonObject.setRetryPolicy(new DefaultRetryPolicy(0, DefaultRetryPolicy.DEFAULT_MAX_RETRIES, DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));
        //jsonObject.setRetryPolicy(new DefaultRetryPolicy(DefaultRetryPolicy.DEFAULT_TIMEOUT_MS * 2, DefaultRetryPolicy.DEFAULT_MAX_RETRIES, DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));

        //int socketTimeout = 30000;//30 seconds - change to what you want
       // RetryPolicy policy = new DefaultRetryPolicy(socketTimeout, DefaultRetryPolicy.DEFAULT_MAX_RETRIES, DefaultRetryPolicy.DEFAULT_BACKOFF_MULT);
       // jsonObject.setRetryPolicy(policy);
        int custom_timeout_ms = 10000;
        DefaultRetryPolicy policy = new DefaultRetryPolicy(custom_timeout_ms,
                DefaultRetryPolicy.DEFAULT_MAX_RETRIES,
                DefaultRetryPolicy.DEFAULT_BACKOFF_MULT);
        jsonObject.setRetryPolicy(policy);
        requestQueue.add(jsonObject);

    }

}

Source 3

Answer 1

使用StringRequest获取Json响应的另一个解决方案

  private void callApi() {
    RequestQueue mrequestQueue;
    StringRequest stringRequest;
    mrequestQueue = Volley.newRequestQueue(this);
    stringRequest = new StringRequest(Request.Method.GET, DATA_URL, new Response.Listener<String>() {
        @Override
        public void onResponse(String response) {

            try {

                JSONObject jsonObject = new JSONObject(response);
                System.out.println("json"+jsonObject);


            } catch (JSONException e) {

                e.printStackTrace();
            }


        }
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
            //Log.i(TAG, "Response: " + error.toString());

        }
    });
    mrequestQueue.add(stringRequest);


}

Answer 2

如果您的应用在响应之前完成，则会导致连接超时。你必须在排球和重试政策中添加连接超时。这是一个例子

        JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(Request.Method.POST,
                url,
                request,
                new Response.Listener<JSONObject>() {
                    @Override
                    public void onResponse(JSONObject response) {


                    }
                }, new VolleyErrorListener(this, AuthController.LOGIN_ERROR)) {
            @Override
            public Map<String, String> getHeaders() throws AuthFailureError {
                return new VolleyHeader().getHeaders();
            }
        };
        jsonObjectRequest.setRetryPolicy(new DefaultRetryPolicy(
                50000,
                0,
                DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));
        NetworkRequestQueue.getInstance(mContext).getRequestQueue().add(jsonObjectRequest);

NetworkRequestQueue类如下：

public class NetworkRequestQueue {

    private static NetworkRequestQueue mInstance;
    private static Context mCtx;
    private RequestQueue mRequestQueue;
    private ImageLoader mImageLoader;


    private NetworkRequestQueue(Context context) {
        mCtx = context;
        mRequestQueue = getRequestQueue();

        mImageLoader = new ImageLoader(mRequestQueue,
                new ImageLoader.ImageCache() {
                    private final LruCache<String, Bitmap>
                            cache = new LruCache<String, Bitmap>(20);

                    @Override
                    public Bitmap getBitmap(String url) {
                        return cache.get(url);
                    }

                    @Override
                    public void putBitmap(String url, Bitmap bitmap) {
                        cache.put(url, bitmap);
                    }
                });
    }

    public static synchronized NetworkRequestQueue getInstance(Context context) {
        if (mInstance == null) {
            mInstance = new NetworkRequestQueue(context);
        }
        return mInstance;
    }

    public RequestQueue getRequestQueue() {
        if (mRequestQueue == null) {
            Cache cache = new DiskBasedCache(mCtx.getCacheDir(), 10 * 1024 * 1024);
            Network network = new BasicNetwork(new HurlStack());
            mRequestQueue = new RequestQueue(cache, network);
            // Don't forget to start the volley request queue
            mRequestQueue.start();
        }
        return mRequestQueue;
    }

    public ImageLoader getImageLoader() {
        return mImageLoader;
    }

}

Answer 3

使用字符串请求

尝试此操作

public class TestActivity extends AppCompatActivity {
        RequestQueue requestQueue;
        String DATA_URL = "http://ec2-54-147-238-136.compute-1.amazonaws.com/hmc/api/getnewsfeeds?order=asc";

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            requestQueue = Volley.newRequestQueue(this);
            callApi();
        }

        private void callApi() {
            StringRequest stringRequest = new StringRequest(Request.Method.GET, DATA_URL, new Response.Listener<String>() {
                @Override
                public void onResponse(String response) {
                    Log.e("res", response);
                }

            }, new Response.ErrorListener() {
                @Override
                public void onErrorResponse(VolleyError error) {
                    Log.e("onErrorResponse: ", error.getLocalizedMessage());
                }

            });

            requestQueue.add(stringRequest);
        }

Answer 4

使用以下命令更改DefaultRetryPolicy：

DefaultRetryPolicy policy = new DefaultRetryPolicy(0,
                    DefaultRetryPolicy.DEFAULT_MAX_RETRIES,
                    DefaultRetryPolicy.DEFAULT_BACKOFF_MULT);
jsonObject.setRetryPolicy(policy);

我无法使用Volley进行网络通话

4 个答案: