虚拟机运行内存，同时获取图像从缓存中 [英] VM running out of memory while getting images from the cache
问题描述
这是我解决这个问题被称为是与堆内存16 MB的设备，我需要解决它。我有线程获取图像从服务器（大图），并让他们缓存，然后显示出来。问题是，我耗尽内存。为了解释远一点我张贴我的日志猫以及一些code：
The problem that I'm addressing is known to be in devices with 16 mb of heap memory, and I need to solve it. I have threads getting images from a server (Big Images) and having them cached then displayed. The problem is that I run out of memory. To explain a little further I'm posting my log cat as well as some code:
public class Test extends Activity implements OnClickListener {
ImageView paint, wheels, shadow;
Button b;
int j = 2;
int i = 1;
String pathToWheels, pathToPaint, pathToShadow;
String stringAngle;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
MemoryInfo dbm = new MemoryInfo();
Debug.getMemoryInfo(dbm);
b = (Button) findViewById(R.id.button1);
b.setOnClickListener(this);
wheels = (ImageView) findViewById(R.id.imageView3);
paint = (ImageView) findViewById(R.id.imageView2);
shadow = (ImageView) findViewById(R.id.imageView1);
while (i < 13) {
stringAngle = Integer.toString(i);
String pathToWheels = url;
String pathToPaint = url;
String pathToShadow = url;
if (Cache.getCacheFile(pathToWheels) == null) {
ImageDownloader downloader1 = new ImageDownloader(wheels);
downloader1
.execute(url);
} else if (Cache.getCacheFile(pathToShadow) == null) {
ImageDownloader downloader2 = new ImageDownloader(shadow);
downloader2
.execute(url);
} else if (Cache.getCacheFile(pathToPaint) == null) {
ImageDownloader downloader = new ImageDownloader(paint);
downloader
.execute(url);
}
i++;
}
}
@Override
protected void onPause() {
super.onPause();
Toast.makeText(getApplicationContext(),"Pause",
Toast.LENGTH_SHORT).show();
}
@Override
public void onClick(View v) {
if (v.getId() == R.id.button1) {
if (j == 13)
{
j = 1;
}
String s = Integer.toString(j);
wheels.setImageBitmap(Cache
.getCacheFile(url));
paint.setImageBitmap(Cache
.getCacheFile(url));
shadow.setImageBitmap(Cache
.getCacheFile(url));
j++;
}
}
}
这是我的缓存类：
public static void saveCacheFile(String cacheUri, Bitmap image) {
if(!isCacheWritable()) return;
Log.i("CACHE S",cacheUri);
cache.saveCacheFile(cacheUri, image);
这是我CacheStore类：
From my CacheStore class:
public Bitmap getCacheFile(String cacheUri) {
if(bitmapMap.containsKey(cacheUri)) return (Bitmap)bitmapMap.get(cacheUri);
if(!cacheMap.containsKey(cacheUri)) return null;
String fileLocalName = cacheMap.get(cacheUri);
File fullCacheDir = new File(Environment.getExternalStorageDirectory().toString(),cacheDir);
File fileUri = new File(fullCacheDir.toString(), fileLocalName);
if(!fileUri.exists()) return null;
Log.i("CACHE", "File "+cacheUri+" has been found in the Cache");
Bitmap bm = BitmapFactory.decodeFile(fileUri.toString());
Bitmap.createScaledBitmap(bm, 480, 320, true);
bitmapMap.put(cacheUri, bm);
return bm;
}
应用程序崩溃，在这一行：位图BM = BitmapFactory.de codeFILE（fileUri.toString（））; 在这里我跑出来的内存。
The app crashes at this line: Bitmap bm = BitmapFactory.decodeFile(fileUri.toString()); where I'm running out of memory.
我的logcat的：
07-06 23:40:20.720: ERROR/dalvikvm-heap(1844): 691200-byte external allocation too large for this process.
07-06 23:40:20.720: ERROR/GraphicsJNI(1844): VM won't let us allocate 691200 bytes
07-06 23:40:20.770: DEBUG/skia(1844): --- decoder->decode returned false
07-06 23:40:20.790: DEBUG/AndroidRuntime(1844): Shutting down VM
07-06 23:40:20.830: WARN/dalvikvm(1844): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): FATAL EXCEPTION: main
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): java.lang.OutOfMemoryError: bitmap size exceeds VM budget
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at android.graphics.BitmapFactory.nativeDecodeStream(Native Method)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at android.graphics.BitmapFactory.decodeStream(BitmapFactory.java:459)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at android.graphics.BitmapFactory.decodeFile(BitmapFactory.java:271)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at android.graphics.BitmapFactory.decodeFile(BitmapFactory.java:296)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at com.cache.CacheStore.getCacheFile(CacheStore.java:117)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at com.cache.Cache.getCacheFile(Cache.java:38)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at com.cache.Test.onClick(Test.java:118)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at android.view.View.performClick(View.java:2408)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at android.view.View$PerformClick.run(View.java:8816)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at android.os.Handler.handleCallback(Handler.java:587)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at android.os.Handler.dispatchMessage(Handler.java:92)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at android.os.Looper.loop(Looper.java:123)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at android.app.ActivityThread.main(ActivityThread.java:4627)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at java.lang.reflect.Method.invokeNative(Native Method)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at java.lang.reflect.Method.invoke(Method.java:521)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
07-06 23:40:20.890: ERROR/AndroidRuntime(1844): at dalvik.system.NativeStart.main(Native Method)
任何帮助将是很大的AP preciated，感谢您的阅读。
Any help would be greatly appreciated, Thanks for reading.
推荐答案
您需要重新采样和缩放你的位图的之前以将它们插入到缓存中，你imagedownloader里面。
You need to re-sample and scale your bitmaps prior to inserting them into the cache, inside your imagedownloader.
在过去，我不得不检测图像的文件大小从网络上下载它之前。如果它太大我只使用一个默认的图片。
In the past I've had to detect the file size of the image prior to downloading it from the web. If it's too large I just use a default image.
此外，我还下调了保存图像的分辨率，通过调整BitmapFactory采样大小，并调整最终图像的大小，你的应用程序。 （这节省了大量的空间用于高速缓存）。
Additionally, I also lowered the resolution of the saved image by adjusting the BitmapFactory Sampling size, and adjusted the size of the final image in your app. (this saved a lot of space for the cache).
请参阅<一href="http://stackoverflow.com/questions/2983073/how-to-know-the-size-of-a-file-before-downloading-it">How下载之前就知道文件的大小？
//somewhere inside image downloader class...
{...}
BitmapFactory.Options options = new BitmapFactory.Options();
if(enableSampling)
options.inSampleSize = 2;
returnBitmap = BitmapFactory.decodeStream(is, null, options);
if(returnBitmap != null)
{
if(scaleImage)
returnBitmap = Bitmap.createScaledBitmap(returnBitmap, width, height, true);
// insert the image into the cache
imageCache.put(url, new SoftReference<Bitmap>(returnBitmap));
// Check the ImageView for nulls
if(imageView != null && callback != null){
ImageDisplayer displayer = new ImageDisplayer(imageView, returnBitmap, parentView, tag);
callback.onImageReceived(displayer);
}
}
{...}
到目前为止，已经为我工作，以及检查INSANE文件大小已经从崩溃多次保存应用程序，更何况它可以跳过在后台downloaing一个巨大的文件。
So far this has worked for me, and the check for INSANE file sizes has saved the app from crashing on numerous occasions, not to mention it can just skip downloaing a massive file in the background.
这篇关于虚拟机运行内存，同时获取图像从缓存中的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
