Question

我正在创建一个通过发出http请求来获取json数据的应用程序，在解析该数据之后，它会在布局中填充视图，还将该json数据存储在列表数据集合中的字符串中。在布局中有一个用Picasso填充的图像视图，最后我在ViewPager 中有两个片段。每个片段都有分页来加载更多数据，并通过获取json数据填充结果列表对于每个页面。

我也必须

将http json响应存储到列表和两个片段

回收站查看堆中两个片段的适配器。

<小时/> 加载更多列表数据时遇到了以下胎儿错误。

Process: mashhood.meshsoft.com.gn_news, PID: 18465 java.lang.OutOfMemoryError: Failed to allocate a 94784012 byte allocation with 4194304 free bytes and 87MB until OOM at dalvik.system.VMRuntime.newNonMovableArray(Native Method) at android.graphics.BitmapFactory.nativeDecodeAsset(Native Method) at android.graphics.BitmapFactory.decodeStream(BitmapFactory.java:655) at android.graphics.BitmapFactory.decodeResourceStream(BitmapFactory.java:483) at android.graphics.drawable.Drawable.createFromResourceStream(Drawable.java:1157) at android.content.res.ResourcesImpl.loadDrawableForCookie(ResourcesImpl.java:720) at android.content.res.ResourcesImpl.loadDrawable(ResourcesImpl.java:571) at android.content.res.Resources.loadDrawable(Resources.java:972) at android.content.res.TypedArray.getDrawable(TypedArray.java:931) at android.widget.ImageView.<init>(ImageView.java:157) at android.widget.ImageView.<init>(ImageView.java:145) at android.support.v7.widget.AppCompatImageView.<init>(AppCompatImageView.java:60) at android.support.v7.widget.AppCompatImageView.<init>(AppCompatImageView.java:56) at android.support.v7.app.AppCompatViewInflater.createView(AppCompatViewInflater.java:106) at android.support.v7.app.AppCompatDelegateImplV9.createView(AppCompatDelegateImplV9.java:1029) at android.support.v7.app.AppCompatDelegateImplV9.onCreateView(AppCompatDelegateImplV9.java:1087) at android.support.v4.view.LayoutInflaterCompatHC$FactoryWrapperHC.onCreateView(LayoutInflaterCompatHC.java:47) at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:769) at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:727) at android.view.LayoutInflater.rInflate(LayoutInflater.java:858) at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:821) at android.view.LayoutInflater.rInflate(LayoutInflater.java:861) at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:821) at android.view.LayoutInflater.rInflate(LayoutInflater.java:861) at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:821) at android.view.LayoutInflater.inflate(LayoutInflater.java:518) at android.view.LayoutInflater.inflate(LayoutInflater.java:426) at mashhood.meshsoft.com.gn_news.movies.Adapters.RecyclerViewAdapters.RecyclerViewForMoiveDiscovery.onCreateViewHolder(RecyclerViewForMoiveDiscovery.java:74) at mashhood.meshsoft.com.gn_news.movies.Adapters.RecyclerViewAdapters.RecyclerViewForMoiveDiscovery.onCreateViewHolder(RecyclerViewForMoiveDiscovery.java:39) at android.support.v7.widget.RecyclerView$Adapter.createViewHolder(RecyclerView.java:6367) at android.support.v7.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline(RecyclerView.java:5555) at android.support.v7.widget.GapWorker.prefetchPositionWithDeadline(GapWorker.java:282) at android.support.v7.widget.GapWorker.flushTaskWithDeadline(GapWorker.java:336) at android.support.v7.widget.GapWorker.flushTasksWithDeadline(GapWorker.java:349) at android.support.v7.widget.GapWorker.prefetch(GapWorker.java:356) at android.support.v7.widget.GapWorker.run(GapWorker.java:387) at android.os.Handler.handleCallback(Handler.java:836) at android.os.Handler.dispatchMessage(Handler.java:103) at android.os.Looper.loop(Looper.java:203) at android.app.ActivityThread.main(ActivityThread.java:6251) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1063) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:924)

<小时/> 适用于RecyclerView的适配器如下

/** * Created by Mashhood on 3/14/2018. */ public class RecyclerViewForMoiveDiscovery extends RecyclerView.Adapter<RecyclerViewForMoiveDiscovery.MyViewHolder> { //this is for the class fields public Context ctx; public List<DiscoverMovies> list; //this is for the list of items //end of the class fields as it should be //this is for the holder for the thread reasoning public Handler handler; //this is for the handler to handle ui thread //end of the holder for the thread reasoning //this is for the constructor public RecyclerViewForMoiveDiscovery(Context context,List<DiscoverMovies>list){ this.ctx=context; //this is for context this.list=list; //this is for the list //this is for the initialization of handler handler=new Handler(); //this is for the handler //end of initialization for handler } //end of the constructor //this is for the RecyclerView Methods @Override public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { //this is for the LayoutInFlator LayoutInflater layoutInflater=LayoutInflater.from(parent.getContext()); View view=layoutInflater.inflate(R.layout.movie_item,parent,false); //end of the LayoutInFlator //this is to create the view holder MyViewHolder myViewHolder=new MyViewHolder(view); //end of view holder return myViewHolder; //this is for myViewHolder } @Override public void onBindViewHolder(final MyViewHolder holder, int position) { try{ final DiscoverMovies discoverMovies=list.get(holder.getAdapterPosition()); //this is for getting current object //now to place it in views holder.movie_rating.setText(discoverMovies.getVoteAverage()); //this is for average vote holder.movie_name.setText(discoverMovies.getTitle()); //this is for the movie name holder.movie_year.setText(discoverMovies.getRelease_date()); //this is for the release date holder.overview_text.setText(discoverMovies.getOverview()); //this is for the overview for movies //end of the placement try{ //this is for the picasso work to get the image Picasso.with(this.ctx).load(discoverMovies.getPoster_path()).error(R.drawable.moive_item_background).into(holder.picture); //end of the picasso work to get the image } catch (Exception ex){ LogPrinting("Exception of type "+ex.getMessage()+"while loading the Image"); }//end of loading the Picture //this is for the click listener for the watch trailer button holder.watch_trailer_button.setOnClickListener(new View.OnClickListener() { public final String movie_id=discoverMovies.getId(); //this is for getting the movie id @Override public void onClick(View v) { if(isOnline()){ FindVideoIdForThatMovie(movie_id); //this is for finding the movie trailer } //this is for the if else{ ToastPrinting("Please get Internet Connection"); }//end of else } }); //end of the block for the click listener for the watch trailer button //this is for the holder watch movie button holder.watch_movie_button.setOnClickListener(new View.OnClickListener() { public final String movie_id=discoverMovies.getId(); //this is for the movie id @Override public void onClick(View v) { try{ if(isOnline()) { Intent i=new Intent(ctx, MoviePlayer.class); i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK); //this is for the new task Bundle b=new Bundle(); b.putString("id",movie_id); i.putExtras(b); ctx.startActivity(i); } else{ ToastPrinting("Please get a Internet Connection"); } } //end of the try catch (Exception ex){ LogPrinting("Exception of type is as follows "+ex.getMessage()); }//end of the catch } }); //end of watch movie button }//end of the try catch(Exception ex){ LogPrinting("Exception while binding the Values with view items "+ex.getMessage()); }//end of catch } // end of the OnBindViewHolder @Override public int getItemCount() { return list.size(); //this is for the list Size } //end of RecyclerView Methods //this is for the Log and Toast printing private static final String TAG = "RecyclerViewForMoiveDis"; public void LogPrinting(String Line){ Log.d(TAG,Line); //this is for the Log Printing }//this is for Log public void ToastPrinting(String Line){ Toast.makeText(this.ctx,Line,Toast.LENGTH_SHORT).show(); }//end of Toast //end of Log And Toast Printing //this is for the ViewHolder class MyViewHolder extends RecyclerView.ViewHolder{ //this is for the class fields public View view; //this is for the view // this is for the public view public TextView movie_rating; //this is for the movie_rating public TextView movie_name; //this is for the movie name public TextView movie_year; //this is for the movie year public TextView overview_text; //this is for the movie overview public Button watch_trailer_button ; //this is for the trailer public Button watch_movie_button; //this is to watch movie public ImageView picture; //this is for the picture //end of the public view //end of view items public MyViewHolder(View itemView) { super(itemView); view=itemView; InitializeComponents(); //this is to initialize the components } //end of the class fields //this is for the initialization of the components public void InitializeComponents(){ try{ movie_rating=(TextView) view.findViewById(R.id.movie_rating); //this is for rating movie_name=(TextView) view.findViewById(R.id.movie_name); //this is for the movie name movie_year=(TextView) view.findViewById(R.id.movie_year); //this is for the movie year overview_text=(TextView) view.findViewById(R.id.overview_text); //this is for overview text watch_trailer_button=(Button) view.findViewById(R.id.watch_trailer_button); //this is for watch trailer button watch_movie_button=(Button) view.findViewById(R.id.watch_movie_button); //watch movie button picture=(ImageView) view.findViewById(R.id.movie_picture); //this is for the movie picture }//end of the try catch (Exception ex){ LogPrinting("Exception of type is as follows "+ex.getMessage()); }//end of catch } //end of the initialization of the components } //end of the ViewHolder //this is for loading the video id for a given movie public void FindVideoIdForThatMovie(final String movieId){ try{ //there we will make the http request for that page Thread t=new Thread(new Runnable() { @Override public void run() { //inner try catch try{ URL url=new URL(new UrlData().GiveMeUrlForVideo(movieId)); //this is for the url URLConnection urlConnection=url.openConnection(); //this is to open http connection BufferedReader bufferedReader=new BufferedReader(new InputStreamReader(urlConnection.getInputStream())); //this is for the buffered reader String Line=""; //this is for the Line String temporary_line=""; //this is for the temporary line //this is for the loop to get the data while((temporary_line=bufferedReader.readLine())!=null){ //keep on reading the Line till no line Line +=temporary_line; //this is for the temporary Line } //end of the loop to get the data //to print what we have got LogPrinting("Coming Video data is as \n"+Line); //this is for the Line //end of printing what we have got //this is for the parsing phase try{ JSONObject mainJSONObject=new JSONObject(Line); //this is for main JSONObject JSONArray jsonArray=mainJSONObject.getJSONArray("results"); //this is for getting the json array JSONObject very_first_object=(JSONObject) jsonArray.get(0); //this is for json array final String youtube_video_id= very_first_object.get("key").toString(); //this is for the youtube video id //now we have to code for sending that video id to new youtube activity handler.post(new Runnable() { @Override public void run() { try{ Intent i=new Intent(ctx, YouTubePlayerActivity.class); i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK); //this is for the new task Bundle b=new Bundle(); b.putString("id",youtube_video_id); i.putExtras(b); ctx.startActivity(i); }//end of try catch (Exception ex3){ LogPrinting("Exception while opening the youtube activity "+ex3.getMessage()); } } }); //end of the activity for sending that video id to new youtube activity }//end of try block catch (Exception exi){ LogPrinting("Exception of type "+exi.getMessage()+" while parsing the json data for videos"); } //end of the parsing phase }//end of try catch (Exception ex){ LogPrinting("Exception of type "+ex.getMessage()+" while loading the videos data for that job "); } //end of inner try catch } }); //end of Thread t.start(); //end of making the http request for that page }//end of the try block catch (Exception ex){ LogPrinting("Exception of type "+ex.getMessage()+" while loading the video id from source in Recycler Adapter for Movies"); }//end of the catch block for loading the movies from movies sources } //end of loading the video id for a given movie //this is for checking either the user is online public boolean isOnline() { ConnectivityManager cm = (ConnectivityManager) this.ctx.getSystemService(ctx.CONNECTIVITY_SERVICE); return cm.getActiveNetworkInfo() != null && cm.getActiveNetworkInfo().isConnectedOrConnecting(); } //end of checking either user is online or not }//end of the class

Answer 1

当dalvik VM拒绝允许分配更多内存资源时，会发生OutOfMemoryError。正如所讨论的问题，使用名为 RecyclerViewForMoiveDiscovery 的RecyclerViewAdapter中的Picasso从远程主机加载大量图像。甚至完成活动后，位图保留在内存中，导致大量内存使用，直到导致OutOfMemoryError。在研究了类似类型的不同案例之后，我知道我们可以在使用毕加索时选择以下。

我们应该设置一个stableKey ，同时将url设置为picasso以获取图片。

Picasso.with（上下文）.load（IMAGE_URL）.stableKey（stable_key）.into（holder.picture）;

on Activity destroy 我们必须通过提供 stableKey 来使该文件无效，如下所示

Picasso.with(context).invalidate(stable_key);

第二种方法是跳过内存缓存并将网络策略设置为NetworkPolicy.NO_CACHE这样做我使用以下代码Picasso.with(context).load(path).skipMemoryCache().networkPolicy(NetworkPolicy.NO_CACHE).error(R.drawable.default_image).into(imageView);这是阻止缓存的更好方法但毕加索启动花费更多时间加载图片。
第三种方式是请求VM为资源提供更多动态内存，为此我们通过在Application标签下的清单中编写android:largeHeap="true"来提出请求。这是一种更简单的方法，但不好，因为如果我们这样做，它可能导致内存泄漏。有效的方法是通过使用Runtime.getRuntime.gc()使内存不受动态分配的对象的影响来管理堆。

如何在管理堆时克服OutOfMemoryError？

1 个答案: