Android Volley StringRequest not working sometimes

问题

I'm using the code below to get some local video URL from an API.

public void getVideoAds(String serverURL){
    String url = "http://"+serverURL+"/video/";

    StringRequest stringRequest = new StringRequest(url, new Response.Listener<String>() {
        @Override
        public void onResponse(String response) {
            try {
                JSONObject jsonObj = new JSONObject(response);
                JSONObject defaultObj = jsonObj.getJSONObject("default");
                JSONArray videoObj = jsonObj.getJSONArray("videos");

                defaultUrl = defaultObj.getString("url");

                for (int i = 0; i < videoObj.length(); i++){
                    JSONObject video = videoObj.getJSONObject(i);

                    VideoAd v = new VideoAd();
                    v.setName(getVideoNameFromLink(video.getString("url")));
                    v.setUrl(video.getString("url"));
                    v.setVideoId(video.getInt("id"));
                    v.setVersion(video.getInt("version"));
                    v.setLocalPath("");

                    vidArrLst.add(v);
                }

                playLoopVideo();
            } catch (Exception e) {
                Log.d(TAG, "getVidAds res err: " + e.getMessage());
            }

        }
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
            Toast.makeText(ctx, "VideoAds Err: "+error.getLocalizedMessage(), Toast.LENGTH_LONG).show();
            Log.d(TAG, "getVidAds err: " + error.getMessage());
        }
    });

    queue.add(stringRequest);
}

And inside onCreate(), I initialize RequestQueue like this.

queue = Volley.newRequestQueue(this);

Sometimes, getVideoAds() works. Sometimes, it doesn't work. The weird thing as well is that I'm not getting any error even after using Exception on my catch(). If it doesn't work, I do a Clean Project -> Rebuild Project -> Make Project and it works again. But after a few builds, mostly just 1 more build, it stops working again.

If you want to know more about playLoopVideo, look at this SO question I made. It's about the video playing part of my app. It currently doesn't play the video if I try to play it inside the onResponse of getVideoAds that's why I made a different question for it because maybe if I fix my Volley the video would play again.

This is my build.gradle(app) if you need it.

apply plugin: 'com.android.application'

android {
    compileSdkVersion 28
    defaultConfig {
        applicationId "biz.net.com.streamer"
        minSdkVersion 17
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
    compileOptions {
        sourceCompatibility 1.8
        targetCompatibility 1.8
    }
}

dependencies {
    implementation fileTree(include: ['*.jar'], dir: 'libs')
    implementation 'com.android.support:appcompat-v7:28.0.0'
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
    implementation 'com.google.android.exoplayer:exoplayer:2.9.1'
    implementation 'com.android.volley:volley:1.1.1'
}

UPDATE:

This is really weird. My getVideoAds() method is called inside another method that calls a method the makes a StringRequest on a different API on the same server. To make it easier to understand below is the code for it.

private void getAdvertisements(final String serverURL){
    getVideoAds(serverURL);
    getMessageAds(serverURL);

    new android.os.Handler().postDelayed(
            new Runnable() {
                public void run() {
                    Log.d(TAG, "Updating ads marquee");
                    getMessageAds(serverURL);
                }
            },
            300000);
}

Currently, the API that getMessageAds() calls don't return anything. I tried to comment it and the handler below and it finally worked. Even the video playing worked. I then tried to uncomment getMessageAds() and add a few messages on the server, everything is working fine. But after I remove the messages, it stops working again.

What could be the reason for this to happen?

回答1:

Add this in volley

  stringRequest.setRetryPolicy(DefaultRetryPolicy(20000, 3, 1.0f));

来源：https://stackoverflow.com/questions/55292686/android-volley-stringrequest-not-working-sometimes