使用改造和 rxjava OutOfMemory 进行分页

Question

我正在尝试手动实现分页。我的做法和sample repository 完全一样。但是有一些我无法理解的错误（在下面的日志中）。我的应用只能加载 2-3 个页面并崩溃。

日志：

06-03 09:55:30.457 22190-22423/example.me E/AndroidRuntime: FATAL EXCEPTION: RxCachedThreadScheduler-1
Process: example.me, PID: 22190
io.reactivex.exceptions.UndeliverableException: java.lang.OutOfMemoryError: Failed to allocate a 168210 byte allocation with 9792 free bytes and 9KB until OOM
    at io.reactivex.plugins.RxJavaPlugins.onError(RxJavaPlugins.java:349)
    at io.reactivex.internal.schedulers.ScheduledRunnable.run(ScheduledRunnable.java:64)
    at io.reactivex.internal.schedulers.ScheduledRunnable.call(ScheduledRunnable.java:52)
    at java.util.concurrent.FutureTask.run(FutureTask.java:237)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:154)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:269)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
    at java.lang.Thread.run(Thread.java:818)
 Caused by: java.lang.OutOfMemoryError: Failed to allocate a 168210 byte allocation with 9792 free bytes and 9KB until OOM
    at java.lang.StringFactory.newStringFromBytes(StringFactory.java:79)
    at java.lang.StringFactory.newStringFromBytes(StringFactory.java:207)
    at okio.Buffer.readString(Buffer.java:631)
    at okio.Buffer.readString(Buffer.java:614)
    at okhttp3.logging.HttpLoggingInterceptor.intercept(HttpLoggingInterceptor.java:254)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:121)
    at okhttp3.RealCall.getResponseWithInterceptorChain(RealCall.java:200)
    at okhttp3.RealCall.execute(RealCall.java:77)
    at retrofit2.OkHttpCall.execute(OkHttpCall.java:180)
    at com.jakewharton.retrofit2.adapter.rxjava2.CallObservable.subscribeActual(CallObservable.java:41)
    at io.reactivex.Observable.subscribe(Observable.java:10838)
    at com.jakewharton.retrofit2.adapter.rxjava2.BodyObservable.subscribeActual(BodyObservable.java:34)
    at io.reactivex.Observable.subscribe(Observable.java:10838)
    at io.reactivex.internal.operators.observable.ObservableSubscribeOn$SubscribeTask.run(ObservableSubscribeOn.java:96)
    at io.reactivex.Scheduler$DisposeTask.run(Scheduler.java:452)
    at io.reactivex.internal.schedulers.ScheduledRunnable.run(ScheduledRunnable.java:61)
    at io.reactivex.internal.schedulers.ScheduledRunnable.call(ScheduledRunnable.java:52) 
    at java.util.concurrent.FutureTask.run(FutureTask.java:237) 
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:154) 
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:269) 
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113) 
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588) 
    at java.lang.Thread.run(Thread.java:818) 

或者有时：

OutOfMemoryError thrown while trying to throw OutOfMemoryError

网络请求代码：

EventApiService eventApiService = RetrofitClient.getApiService();
    compositeDisposable.add(eventApiService.getJson(citySlug, FIRST_PAGE_TO_LOAD)
            .observeOn(AndroidSchedulers.mainThread())
            .subscribe(this::handleFirstEventsDataResponse, this::handleFirstEventsDataResponseError));

响应处理代码（首页）：

@Override
public void showData(ResponseData responseData) {
    this.events = responseData.getEvents();
    this.responseData = responseData;
    eventAdapter = new EventAdapter(responseData.getEvents(), eventClickListener);
    recyclerView.setAdapter(eventAdapter);
}

响应处理代码（下一页）：

@Override
public void showAdditionalData(ResponseData responseData) {
    eventAdapter.removeLoadingItem();
    isLoading = false;
    eventAdapter.addData(responseData.getEvents());
    eventAdapter.addLoadingItem();
}

改造搭建方法：

private static Retrofit getRetrofitInstance() {
    HttpLoggingInterceptor logging = new HttpLoggingInterceptor();
    logging.setLevel(HttpLoggingInterceptor.Level.BODY);
    OkHttpClient.Builder builder = new OkHttpClient.Builder();
    builder.addInterceptor(logging);
    OkHttpClient client = builder.build();
    return new Retrofit.Builder()
            .baseUrl(BASE_URL)
            .client(client)
            .addCallAdapterFactory(RxJava2CallAdapterFactory.createWithScheduler(Schedulers.io()))
            .addConverterFactory(GsonConverterFactory.create())
            .build();
}

我想做什么：

• android:largeHeap="true" 在 AndroidManifest 中。它可以让您再加载一页。
• 将 RxJava 请求替换为普通的 Retrofit2 - 没有强烈反应。
• 从改造构建器中删除 OkHttpClient - 没有强烈反应。

UPD：

我们发现原因在于图像加载。我添加了fit().centerCrop()，现在它加载了 5-7 页并崩溃了。我在适配器中的图像加载代码 sn-p：

String imageUrl = "";
            try {
                imageUrl = event.getImages().get(0).getImageUrl();
            } catch (NullPointerException e) {
                e.printStackTrace();
            }

            if (eventViewHolder.ivPhoto != null) {
                Picasso.get().load(imageUrl).fit().centerCrop().into(eventViewHolder.ivPhoto);
            }

新的崩溃日志：

06-03 10:32:07.791 17978-17986/example.me E/System: Uncaught exception thrown by finalizer
06-03 10:32:08.438 17978-17986/example.me E/System: java.lang.OutOfMemoryError: OutOfMemoryError thrown while trying to throw OutOfMemoryError; no stack trace available
06-03 10:32:08.439 17978-18715/example.me E/AndroidRuntime: FATAL EXCEPTION: Thread-163055
Process: example.me, PID: 17978
java.lang.OutOfMemoryError: OutOfMemoryError thrown while trying to throw OutOfMemoryError; no stack trace available

Answer 1

当您使用 HttpLoggingInterceptor.Level.BODY 时，您尝试下载大文件，会将所有正文保存在内存中以供日志使用。

这很容易让 OOM 。

尝试删除日志正文或仅记录 NONE 、基本或标题，然后重试。

当你尝试获取大文件时，可以像这样在 retrofit2 中使用@Streaming。

@Streaming
@GET
fun downloadFileWithDynamicUrlSync(@Url fileUrl: String): Call<ResponseBody>

尝试在此处删除日志正文。

HttpLoggingInterceptor logging = new HttpLoggingInterceptor();
logging.setLevel(HttpLoggingInterceptor.Level.BODY);

试试这个。

HttpLoggingInterceptor logging = new HttpLoggingInterceptor();
logging.setLevel(HttpLoggingInterceptor.Level.NONE);

Answer 2

也许当毕加索尝试设置图像时，viewholder 已经为空。对于调试，您可以使用 picasso 独立加载图像并自行设置图像。不要忘记在设置之前检查可空性。

Picasso.with(context)
            .load(imageUrl)
            .into(imageView, new com.squareup.picasso.Callback() {
                        @Override
                        public void onSuccess() {
                            //check nullability and set image

                        }

                        @Override
                        public void onError() {

               }