以下のクラスは、RSS フィードを解析し、AsyncTask を使用して画像/テキストを画面に描画します。NASA の RSS フィードを使用していました。昨夜、同じフィードに切り替えましたが、画像が大きくなりました。更新ボタンを押しようとすると、メモリが不足します。どうすればこれを処理できますか? 画像が非常に大きいため（他の画像の36kbと比較して約6mb）、静的であることも役に立たないことを読んだことがあります。壁紙を画像として設定するときにクラスの別のインスタンスとして final_image を取得する必要があるため、静的であることを回避する方法はありません。したがって、以下のすべてが小さい画像で機能します。大きな画像では一度は機能しますが、更新ボタン (RssParseSync.execute() を実行するだけ) を押そうとすると更新に失敗し、以下のエラーが発生します。
public class RssParseSync extends AsyncTask<String,String,Bitmap>{
private Activity parent;
private ProgressDialog dialog;
private static Bitmap final_image; //must be static because a new instance is required to access getFinalImage();
public RssParseSync(Activity parent){this.parent =parent;}//constructor to pass parent activity, need this to call findViewById
private XmlPullParser makeParser(){
}
@Override
protected Bitmap doInBackground(String... info){
URL iotd;
int count=info.length;
String title="",link="",description="",date="";
System.out.println("Number of params is "+count);
try{
iotd = new URL("http://www.nasa.gov/rss/lg_image_of_the_day.rss");//set URl
BufferedReader in;//new BufferedReader
in = new BufferedReader(new InputStreamReader(iotd.openStream()));//get rss
XmlPullParserFactory factory;
factory = XmlPullParserFactory.newInstance();//new factory
factory.setNamespaceAware(true);
XmlPullParser xpp;
xpp = factory.newPullParser();
xpp.setInput(in);
//rss is now parsed, free to use XmlPullParser functions to move around and evaulate the rss
int eventType;
eventType = xpp.getEventType();//returns an int which mean different things (START_DOCUMENT,START_TAG,etc)
while(eventType!=XmlPullParser.END_DOCUMENT){//while the document has words
switch(eventType){
case XmlPullParser.START_DOCUMENT://beginning of xml
break;
case XmlPullParser.START_TAG://case : at beginning of new tag
String tagName=xpp.getName();
System.out.println(tagName+" "+xpp.getDepth());
if(tagName.equals("title")&& xpp.getDepth()==4){//depth is specific to this certain rss feed, there are multiple tags with the same names
info[0]=xpp.nextText();
title=info[0];
}
if(tagName.equals("description")&& xpp.getDepth()==4){//depth is specific to this certain rss feed, there are multiple tags with the same names
info[1]=xpp.nextText();
description=info[1];
StringBuilder tabbed=new StringBuilder(description);
tabbed.insert(0, "\t");
description=tabbed.toString();
//info[1]=description;
}
if(tagName.equals("pubDate")){//no depth needed, only one tag is named pubDate
info[2]=xpp.nextText();
date=info[2];
}
if(tagName.equals("enclosure")&&xpp.getDepth()==4){//this is where our image url is. this url is an attribute of the "enclosure" tag
//System.out.println("Enclosure has "+xpp.getAttributeCount());
for(int i=0; i<=xpp.getAttributeCount()-1; i++){
System.out.println("in for");
if(xpp.getAttributeName(i).equals("url")){
link=xpp.getAttributeValue(i);
info[3]=link;
//System.out.println(link);
}
}
}
break;
}
eventType=xpp.next();
}//switch
publishProgress(title,description,date,link);
in.close();//close BufferedReader
} catch (MalformedURLException e){
e.printStackTrace();
}catch(XmlPullParserException e1){
e1.printStackTrace();
}catch(IOException e2){
e2.printStackTrace();
}
Bitmap image=getBitmapFromURL(info[3]);
return image;
}
@Override
protected void onProgressUpdate(String... progress){
try {
System.out.println("onProgressUpdate");
resetDisplay(progress[0],progress[1],progress[2],progress[3]);//feeding parsed rss values, title, description, date, and link
} catch (MalformedURLException e) {//both exceptions are thrown by resetDisplay
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
protected void onPostExecute(Bitmap image){//error when doing this in resetDisplay.... onPostExecute is invoked by the ui thread so this may be why it works here and not in resetDisplay
ImageView imageView=(ImageView) parent.findViewById(R.id.imageDisplay);
imageView.setImageBitmap(image);
final_image=image;
dialog.dismiss();
}
protected void onPreExecute(){
dialog=ProgressDialog.show(parent, "Loading", "Loading the image of the day");
}
private void resetDisplay(String title, String description,String date, String link) throws MalformedURLException, IOException{
TextView titleView=(TextView) parent.findViewById(R.id.imageTitle);
titleView.setText(title);
TextView dateView=(TextView) parent.findViewById(R.id.imageDate);
dateView.setText(date);
TextView descriptionView=(TextView) parent.findViewById(R.id.imageDescription);
descriptionView.setText(description);
}
public Bitmap getBitmapFromURL(String url) {
try {
Bitmap bitmap=null;
InputStream input = new java.net.URL(url).openStream();
bitmap = BitmapFactory.decodeStream(input);//Decode an input stream into a bitmap. If the input stream is null, or cannot be used to decode a bitmap, the function returns null.
input.close();
return bitmap;
} catch (IOException ioe) { return null; }
}
public Bitmap getFinalImage(){
return final_image;
};
}//class
リフレッシュ方法
public void onRefresh(){
System.out.println("in onRefresh");
new RssParseSync(getActivity()).execute(title,description,date,link);
}
Logcat ログ
07-20 17:44:18.470: I/System.out(7581): onProgressUpdate
07-20 17:44:18.770: D/dalvikvm(7581): GC_FOR_ALLOC freed 190K, 3% free 26538K/27299K, paused 46ms
07-20 17:44:18.770: I/dalvikvm-heap(7581): Forcing collection of SoftReferences for 24107536-byte allocation
07-20 17:44:18.790: D/dalvikvm(7581): GC_BEFORE_OOM freed 18K, 3% free 26519K/27299K, paused 23ms
07-20 17:44:18.790: E/dalvikvm-heap(7581): Out of memory on a 24107536-byte allocation.
07-20 17:44:18.790: I/dalvikvm(7581): "AsyncTask #2" prio=5 tid=13 RUNNABLE
07-20 17:44:18.790: I/dalvikvm(7581): | group="main" sCount=0 dsCount=0 obj=0x40d6cac8 self=0x2412840
07-20 17:44:18.790: I/dalvikvm(7581): | sysTid=7646 nice=10 sched=0/0 cgrp=default handle=32889544
07-20 17:44:18.790: I/dalvikvm(7581): | schedstat=( 0 0 0 ) utm=7 stm=0 core=1
07-20 17:44:18.790: I/dalvikvm(7581): at android.graphics.BitmapFactory.nativeDecodeStream(Native Method)
07-20 17:44:18.800: I/dalvikvm(7581): at android.graphics.BitmapFactory.decodeStream(BitmapFactory.java:719)
07-20 17:44:18.800: I/dalvikvm(7581): at android.graphics.BitmapFactory.decodeStream(BitmapFactory.java:791)
07-20 17:44:18.800: I/dalvikvm(7581): at com.wajumbie.nasadailyimage.RssParseSync.getBitmapFromURL(RssParseSync.java:162)
07-20 17:44:18.800: I/dalvikvm(7581): at com.wajumbie.nasadailyimage.RssParseSync.doInBackground(RssParseSync.java:116)
07-20 17:44:18.800: I/dalvikvm(7581): at com.wajumbie.nasadailyimage.RssParseSync.doInBackground(RssParseSync.java:1)
07-20 17:44:18.800: I/dalvikvm(7581): at android.os.AsyncTask$2.call(AsyncTask.java:264)
07-20 17:44:18.800: I/dalvikvm(7581): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
07-20 17:44:18.800: I/dalvikvm(7581): at java.util.concurrent.FutureTask.run(FutureTask.java:137)
07-20 17:44:18.800: I/dalvikvm(7581): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:208)
07-20 17:44:18.800: I/dalvikvm(7581): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
07-20 17:44:18.800: I/dalvikvm(7581): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
07-20 17:44:18.800: I/dalvikvm(7581): at java.lang.Thread.run(Thread.java:864)
07-20 17:44:18.800: E/dalvikvm(7581): Out of memory: Heap Size=34019KB, Allocated=26519KB, Limit=49152KB
07-20 17:44:18.800: E/dalvikvm(7581): Extra info: Footprint=27299KB, Allowed Footprint=34019KB, Trimmed=1212KB
07-20 17:44:18.800: D/skia(7581): --- decoder->decode returned false
07-20 17:44:18.800: W/dalvikvm(7581): threadid=13: thread exiting with uncaught exception (group=0x40aa3a08)
07-20 17:44:18.810: E/AndroidRuntime(7581): FATAL EXCEPTION: AsyncTask #2
07-20 17:44:18.810: E/AndroidRuntime(7581): java.lang.RuntimeException: An error occured while executing doInBackground()
07-20 17:44:18.810: E/AndroidRuntime(7581): at android.os.AsyncTask$3.done(AsyncTask.java:278)
07-20 17:44:18.810: E/AndroidRuntime(7581): at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273)
07-20 17:44:18.810: E/AndroidRuntime(7581): at java.util.concurrent.FutureTask.setException(FutureTask.java:124)
07-20 17:44:18.810: E/AndroidRuntime(7581): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307)
07-20 17:44:18.810: E/AndroidRuntime(7581): at java.util.concurrent.FutureTask.run(FutureTask.java:137)
07-20 17:44:18.810: E/AndroidRuntime(7581): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:208)
07-20 17:44:18.810: E/AndroidRuntime(7581): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
07-20 17:44:18.810: E/AndroidRuntime(7581): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
07-20 17:44:18.810: E/AndroidRuntime(7581): at java.lang.Thread.run(Thread.java:864)
07-20 17:44:18.810: E/AndroidRuntime(7581): Caused by: java.lang.OutOfMemoryError: (Heap Size=34019KB, Allocated=26519KB)
07-20 17:44:18.810: E/AndroidRuntime(7581): at android.graphics.BitmapFactory.nativeDecodeStream(Native Method)
07-20 17:44:18.810: E/AndroidRuntime(7581): at android.graphics.BitmapFactory.decodeStream(BitmapFactory.java:719)
07-20 17:44:18.810: E/AndroidRuntime(7581): at android.graphics.BitmapFactory.decodeStream(BitmapFactory.java:791)
07-20 17:44:18.810: E/AndroidRuntime(7581): at com.wajumbie.nasadailyimage.RssParseSync.getBitmapFromURL(RssParseSync.java:162)
07-20 17:44:18.810: E/AndroidRuntime(7581): at com.wajumbie.nasadailyimage.RssParseSync.doInBackground(RssParseSync.java:116)
07-20 17:44:18.810: E/AndroidRuntime(7581): at com.wajumbie.nasadailyimage.RssParseSync.doInBackground(RssParseSync.java:1)
07-20 17:44:18.810: E/AndroidRuntime(7581): at android.os.AsyncTask$2.call(AsyncTask.java:264)
07-20 17:44:18.810: E/AndroidRuntime(7581): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
07-20 17:44:18.810: E/AndroidRuntime(7581): ... 5 more
07-20 17:44:19.061: D/OpenGLRenderer(7581): Flushing caches (mode 0)
07-20 17:44:19.061: D/memalloc(7581): ion: Unmapping buffer base:0x52738000 size:2088960
07-20 17:44:19.061: D/memalloc(7581): ion: Unmapping buffer base:0x52f7c000 size:2088960
07-20 17:44:19.061: D/memalloc(7581): ion: Unmapping buffer base:0x53477000 size:2088960
07-20 17:44:19.081: D/OpenGLRenderer(7581): Flushing caches (mode 0)
07-20 17:44:19.111: D/memalloc(7581): ion: Unmapping buffer base:0x52bea000 size:524288
07-20 17:44:19.121: D/memalloc(7581): ion: Unmapping buffer base:0x5367d000 size:524288
07-20 17:44:19.121: D/memalloc(7581): ion: Unmapping buffer base:0x53326000 size:524288
07-20 17:44:19.141: D/OpenGLRenderer(7581): Flushing caches (mode 2)
07-20 17:44:19.181: E/WindowManager(7581): Activity com.wajumbie.nasadailyimage.NasaAppActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@40d92b30 that was originally added here
07-20 17:44:19.181: E/WindowManager(7581): android.view.WindowLeaked: Activity com.wajumbie.nasadailyimage.NasaAppActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@40d92b30 that was originally added here
07-20 17:44:19.181: E/WindowManager(7581): at android.view.ViewRootImpl.<init>(ViewRootImpl.java:380)
07-20 17:44:19.181: E/WindowManager(7581): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:372)
07-20 17:44:19.181: E/WindowManager(7581): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:320)
07-20 17:44:19.181: E/WindowManager(7581): at android.view.WindowManagerImpl$CompatModeWrapper.addView(WindowManagerImpl.java:152)
07-20 17:44:19.181: E/WindowManager(7581): at android.view.Window$LocalWindowManager.addView(Window.java:557)
07-20 17:44:19.181: E/WindowManager(7581): at android.app.Dialog.show(Dialog.java:301)
07-20 17:44:19.181: E/WindowManager(7581): at android.app.ProgressDialog.show(ProgressDialog.java:116)
07-20 17:44:19.181: E/WindowManager(7581): at android.app.ProgressDialog.show(ProgressDialog.java:99)
07-20 17:44:19.181: E/WindowManager(7581): at android.app.ProgressDialog.show(ProgressDialog.java:94)
07-20 17:44:19.181: E/WindowManager(7581): at com.wajumbie.nasadailyimage.RssParseSync.onPreExecute(RssParseSync.java:142)
07-20 17:44:19.181: E/WindowManager(7581): at android.os.AsyncTask.executeOnExecutor(AsyncTask.java:561)
07-20 17:44:19.181: E/WindowManager(7581): at android.os.AsyncTask.execute(AsyncTask.java:511)
07-20 17:44:19.181: E/WindowManager(7581): at com.wajumbie.nasadailyimage.NasaDailyImage.onRefresh(NasaDailyImage.java:57)
07-20 17:44:19.181: E/WindowManager(7581): at com.wajumbie.nasadailyimage.NasaAppActivity$1.run(NasaAppActivity.java:48)
07-20 17:44:19.181: E/WindowManager(7581): at com.wajumbie.nasadailyimage.NasaAppActivity.onRefreshClicked(NasaAppActivity.java:51)
07-20 17:44:19.181: E/WindowManager(7581): at java.lang.reflect.Method.invokeNative(Native Method)
07-20 17:44:19.181: E/WindowManager(7581): at java.lang.reflect.Method.invoke(Method.java:511)
07-20 17:44:19.181: E/WindowManager(7581): at android.view.View$1.onClick(View.java:3066)
07-20 17:44:19.181: E/WindowManager(7581): at android.view.View.performClick(View.java:3538)
07-20 17:44:19.181: E/WindowManager(7581): at android.view.View$PerformClick.run(View.java:14330)
07-20 17:44:19.181: E/WindowManager(7581): at android.os.Handler.handleCallback(Handler.java:607)
07-20 17:44:19.181: E/WindowManager(7581): at android.os.Handler.dispatchMessage(Handler.java:92)
07-20 17:44:19.181: E/WindowManager(7581): at android.os.Looper.loop(Looper.java:156)
07-20 17:44:19.181: E/WindowManager(7581): at android.app.ActivityThread.main(ActivityThread.java:5008)
07-20 17:44:19.181: E/WindowManager(7581): at java.lang.reflect.Method.invokeNative(Native Method)
07-20 17:44:19.181: E/WindowManager(7581): at java.lang.reflect.Method.invoke(Method.java:511)
07-20 17:44:19.181: E/WindowManager(7581): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
07-20 17:44:19.181: E/WindowManager(7581): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
07-20 17:44:19.181: E/WindowManager(7581): at dalvik.system.NativeStart.main(Native Method)