Android java.lang.OutOfMemoryError?

问题:

04-25 08:19:10.111    2431-2603/com.example.francesco.guidedautorewithtabs E/art﹕ Throwing OutOfMemoryError "Failed to allocate a 4194316 byte allocation with 1983651 free bytes and 1937KB until OOM"
04-25 08:19:10.114    2431-2603/com.example.francesco.guidedautorewithtabs E/AndroidRuntime﹕ FATAL EXCEPTION: GLThread 285
Process: com.example.francesco.guidedautorewithtabs, PID: 2431
java.lang.OutOfMemoryError: Failed to allocate a 4194316 byte allocation with 1983651 free bytes and 1937KB until OOM
        at dalvik.system.VMRuntime.newNonMovableArray(Native Method)
        at android.graphics.Bitmap.nativeCreate(Native Method)
        at android.graphics.Bitmap.createBitmap(Bitmap.java:817)
        at android.graphics.Bitmap.createBitmap(Bitmap.java:794)
        at android.graphics.Bitmap.createBitmap(Bitmap.java:761)
        at com.google.maps.api.android.lib6.gmm6.o.c.l.a(Unknown Source)
        at com.google.maps.api.android.lib6.gmm6.o.c.o.a(Unknown Source)
        at com.google.maps.api.android.lib6.gmm6.o.c.o.a(Unknown Source)
        at com.google.maps.api.android.lib6.gmm6.o.c.o.b(Unknown Source)
        at com.google.maps.api.android.lib6.gmm6.o.c.b.ak.a(Unknown Source)
        at com.google.maps.api.android.lib6.gmm6.o.c.b.as.a(Unknown Source)
        at com.google.maps.api.android.lib6.gmm6.o.x.a(Unknown Source)
        at com.google.maps.api.android.lib6.gmm6.o.l.a(Unknown Source)
        at com.google.maps.api.android.lib6.gmm6.o.l.b(Unknown Source)
        at com.google.maps.api.android.lib6.gmm6.o.cj.g(Unknown Source)
        at com.google.maps.api.android.lib6.gmm6.o.cj.run(Unknown Source)

In my Android code i have a lot of images that have to be displayed into different fragment. Several of this are stored in the assets folder, other picked up from an http request. For this reason i implement image caching in order to do not go against the java.lang.OutOfMemoryError, but nevertheless this error seems to persist. How can i resolve this problem? Below my implementation of image caching.

ImageLoader

public class ImageLoader {
MemoryCache memoryCache=new MemoryCache();
FileCache fileCache;
private Map<ImageView, String> imageViews=Collections.synchronizedMap(new WeakHashMap<ImageView, String>());
ExecutorService executorService;
private Context context;

public ImageLoader(Context context){
    this.context=context;
    fileCache=new FileCache(context);
    executorService=Executors.newFixedThreadPool(5);
}

final int stub_id= R.drawable.no_image;
public void DisplayImage(String url, ImageView imageView)
{
    imageViews.put(imageView, url);
    Bitmap bitmap=memoryCache.get(url);
    if(bitmap!=null)
        imageView.setImageBitmap(bitmap);
    else
    {
        queuePhoto(url, imageView);
        imageView.setImageResource(stub_id);
    }
}

private void queuePhoto(String url, ImageView imageView)
{
    PhotoToLoad p=new PhotoToLoad(url, imageView);
    executorService.submit(new PhotosLoader(p));
}

private Bitmap getBitmapFromAsset(String strName)
{
    AssetManager assetManager = context.getAssets();
    InputStream istr = null;
    try {
        istr = assetManager.open(strName);
    } catch (IOException e) {
        e.printStackTrace();
    }
    Bitmap bitmap = BitmapFactory.decodeStream(istr);
    return bitmap;
}

private Bitmap getBitmap(String url)
{
    File f=fileCache.getFile(url);

    //from SD cache
    Bitmap b = decodeFile(f);
    if(b!=null)
        return b;

    //from assets
    Bitmap bm = getBitmapFromAsset(url);

    if(bm!=null)
        return bm;

    //from web
    try {
        Bitmap bitmap=null;
        URL imageUrl = new URL(url);
        HttpURLConnection conn = (HttpURLConnection)imageUrl.openConnection();
        conn.setConnectTimeout(30000);
        conn.setReadTimeout(30000);
        conn.setInstanceFollowRedirects(true);
        InputStream is=conn.getInputStream();
        OutputStream os = new FileOutputStream(f);
        Utils.CopyStream(is, os);
        os.close();
        bitmap = decodeFile(f);
        return bitmap;
    } catch (Throwable ex){
        ex.printStackTrace();
        if(ex instanceof OutOfMemoryError)
            memoryCache.clear();
        return null;
    }
}

//decodes image and scales it to reduce memory consumption
private Bitmap decodeFile(File f){
    try {
        //decode image size
        BitmapFactory.Options o = new BitmapFactory.Options();
        o.inJustDecodeBounds = true;
        BitmapFactory.decodeStream(new FileInputStream(f),null,o);

        //Find the correct scale value. It should be the power of 2.
        final int REQUIRED_SIZE=70;
        int width_tmp=o.outWidth, height_tmp=o.outHeight;
        int scale=1;
        while(true){
            if(width_tmp/2<REQUIRED_SIZE || height_tmp/2<REQUIRED_SIZE)
                break;
            width_tmp/=2;
            height_tmp/=2;
            scale*=2;
        }

        //decode with inSampleSize
        BitmapFactory.Options o2 = new BitmapFactory.Options();
        o2.inSampleSize=scale;
        return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
    } catch (FileNotFoundException e) {}
    return null;
}

//Task for the queue
private class PhotoToLoad
{
    public String url;
    public ImageView imageView;
    public PhotoToLoad(String u, ImageView i){
        url=u;
        imageView=i;
    }
}

class PhotosLoader implements Runnable {
    PhotoToLoad photoToLoad;
    PhotosLoader(PhotoToLoad photoToLoad){
        this.photoToLoad=photoToLoad;
    }

    @Override
    public void run() {
        if(imageViewReused(photoToLoad))
            return;
        Bitmap bmp=getBitmap(photoToLoad.url);
        memoryCache.put(photoToLoad.url, bmp);
        if(imageViewReused(photoToLoad))
            return;
        BitmapDisplayer bd=new BitmapDisplayer(bmp, photoToLoad);
        Activity a=(Activity)photoToLoad.imageView.getContext();
        a.runOnUiThread(bd);
    }
}

boolean imageViewReused(PhotoToLoad photoToLoad){
    String tag=imageViews.get(photoToLoad.imageView);
    if(tag==null || !tag.equals(photoToLoad.url))
        return true;
    return false;
}

//Used to display bitmap in the UI thread
class BitmapDisplayer implements Runnable
{
    Bitmap bitmap;
    PhotoToLoad photoToLoad;
    public BitmapDisplayer(Bitmap b, PhotoToLoad p){bitmap=b;photoToLoad=p;}
    public void run()
    {
        if(imageViewReused(photoToLoad))
            return;
        if(bitmap!=null)
            photoToLoad.imageView.setImageBitmap(bitmap);
        else
            photoToLoad.imageView.setImageResource(stub_id);
    }
}

public void clearCache() {
    memoryCache.clear();
    fileCache.clear();
}
}

FileCache

public class FileCache {

private File cacheDir;

public FileCache(Context context){
    //Find the dir to save cached images
    if (android.os.Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED))
        cacheDir=new File(android.os.Environment.getExternalStorageDirectory(),"TTImages_cache");
    else
        cacheDir=context.getCacheDir();
    if(!cacheDir.exists())
        cacheDir.mkdirs();
}

public File getFile(String url){
    //I identify images by hashcode. Not a perfect solution, good for the demo.
    String filename=String.valueOf(url.hashCode());
    //Another possible solution (thanks to grantland)
    //String filename = URLEncoder.encode(url);
    File f = new File(cacheDir, filename);
    return f;

}

public void clear(){
    File[] files=cacheDir.listFiles();
    if(files==null)
        return;
    for(File f:files)
        f.delete();
}

}

MemoryCache

public class MemoryCache {

private static final String TAG = "MemoryCache";
private Map<String, Bitmap> cache=Collections.synchronizedMap(
        new LinkedHashMap<String, Bitmap>(10,1.5f,true));//Last argument true for LRU ordering
private long size=0;//current allocated size
private long limit=1000000;//max memory in bytes

public MemoryCache(){
    //use 25% of available heap size
    setLimit(Runtime.getRuntime().maxMemory()/4);
}

public void setLimit(long new_limit){
    limit=new_limit;
    Log.i(TAG, "MemoryCache will use up to "+limit/1024./1024.+"MB");
}

public Bitmap get(String id){
    try{
        if(!cache.containsKey(id))
            return null;
        //NullPointerException sometimes happen here http://code.google.com/p/osmdroid/issues/detail?id=78
        return cache.get(id);
    }catch(NullPointerException ex){
        ex.printStackTrace();
        return null;
    }
}

public void put(String id, Bitmap bitmap){
    try{
        if(cache.containsKey(id))
            size-=getSizeInBytes(cache.get(id));
        cache.put(id, bitmap);
        size+=getSizeInBytes(bitmap);
        checkSize();
    }catch(Throwable th){
        th.printStackTrace();
    }
}

private void checkSize() {
    Log.i(TAG, "cache size="+size+" length="+cache.size());
    if(size>limit){
        Iterator<Entry<String, Bitmap>> iter=cache.entrySet().iterator();//least recently accessed item will be the first one iterated
        while(iter.hasNext()){
            Entry<String, Bitmap> entry=iter.next();
            size-=getSizeInBytes(entry.getValue());
            iter.remove();
            if(size<=limit)
                break;
        }
        Log.i(TAG, "Clean cache. New size "+cache.size());
    }
}

public void clear() {
    try{
        //NullPointerException sometimes happen here http://code.google.com/p/osmdroid/issues/detail?id=78
        cache.clear();
        size=0;
    }catch(NullPointerException ex){
        ex.printStackTrace();
    }
}

long getSizeInBytes(Bitmap bitmap) {
    if(bitmap==null)
        return 0;
    return bitmap.getRowBytes() * bitmap.getHeight();
}
}

Utils

public class Utils {
public static void CopyStream(InputStream is, OutputStream os)
{
    final int buffer_size=1024;
    try
    {
        byte[] bytes=new byte[buffer_size];
        for(;;)
        {
            int count=is.read(bytes, 0, buffer_size);
            if(count==-1)
                break;
            os.write(bytes, 0, count);
        }
    }
    catch(Exception ex){}
}
}

回答1:

Try this may help you add this tag in your manifest file.

<application android:largeHeap="true">
</application>

it will allocate large heap for your app

回答2:

Loading Large Bitmaps Efficiently : http://developer.android.com/training/displaying-bitmaps/load-bitmap.html

Caching Bitmaps: http://developer.android.com/training/displaying-bitmaps/cache-bitmap.html

Try to resize the image and recycle bitmap also after usage.

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;

 public class ImageResizer {

 public static Bitmap decodeSampledBitmapFromFile(String filename,
    int reqWidth, int reqHeight) {
// First decode with inJustDecodeBounds=true to check dimensions
final BitmapFactory.Options
        options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(filename, options);
// Calculate inSampleSize
options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);
// Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;
return BitmapFactory.decodeFile(filename, options);
 }

   public static int calculateInSampleSize(BitmapFactory.Options options,
    int reqWidth, int reqHeight) {
// BEGIN_INCLUDE (calculate_sample_size)
// Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;

if (height > reqHeight || width > reqWidth) {

    final int halfHeight = height / 2;
    final int halfWidth = width / 2;

    // Calculate the largest inSampleSize value that is a power of 2 and keeps both
    // height and width larger than the requested height and width.
    while ((halfHeight / inSampleSize) > reqHeight
            && (halfWidth / inSampleSize) > reqWidth) {
        inSampleSize *= 2;
    }

    // This offers some additional logic in case the image has a strange
    // aspect ratio. For example, a panorama may have a much larger
    // width than height. In these cases the total pixels might still
    // end up being too large to fit comfortably in memory, so we should
    // be more aggressive with sample down the image (=larger inSampleSize).

    long totalPixels = width * height / inSampleSize;

    // Anything more than 2x the requested pixels we'll sample down further
    final long totalReqPixelsCap = reqWidth * reqHeight * 2;

    while (totalPixels > totalReqPixelsCap) {
        inSampleSize *= 2;
        totalPixels /= 2;
    }
}
return inSampleSize;
// END_INCLUDE (calculate_sample_size)
 }
 }

回答3:

This is because of low memory, size of your image file is large, to solve this problem add this method in your class:

public static Bitmap decodeImageFile(File f,int WIDTH,int HIGHT){
             try {
                 //Decode image size
                 BitmapFactory.Options o = new BitmapFactory.Options();
                 o.inJustDecodeBounds = true;
                 BitmapFactory.decodeStream(new FileInputStream(f),null,o);

                 //The new size we want to scale to
                 final int REQUIRED_WIDTH=WIDTH;
                 final int REQUIRED_HIGHT=HIGHT;
                 //Find the correct scale value. It should be the power of 2.
                 int scale=1;
                 while(o.outWidth/scale/2>=REQUIRED_WIDTH && o.outHeight/scale/2>=REQUIRED_HIGHT)
                     scale*=2;

                 //Decode with inSampleSize
                 BitmapFactory.Options o2 = new BitmapFactory.Options();
                 o2.inSampleSize=scale;
                 return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
             } catch (FileNotFoundException e) {}
             return null;
            }

Then call this method where you using this:

Bitmap b = decodeFile(f);

use this insted:

Bitmap b = decodeImageFile(f, 1280, 720);

回答4:

    <application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:largeHeap="true"/>

回答5:

OutOfMemoryError is the most common problem occured in android while especially dealing with bitmaps. This error is thrown by the Java Virtual Machine (JVM) when an object cannot be allocated due to lack of memory space and also, the garbage collector cannot free some space.

As mentioned by Aleksey, you can add below entities in your manifest file android:hardwareAccelerated="false" , android:largeHeap="true" it will work for some environment's.

<application
    android:allowBackup="true"
    android:hardwareAccelerated="false"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:largeHeap="true"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">

回答6:

Try to call System.gc() manually before you load image to memory and when you don't need to use this image object.

回答7:

You can try this code....

BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = 8;    

Bitmap bm = BitmapFactory.decodeFile(img,options);
imageView.setImageBitmap(bm);