Android java.lang.OutOfMemoryError？答案

【问题标题】：Android java.lang.OutOfMemoryError?Android java.lang.OutOfMemoryError？
【发布时间】：2015-07-03 21:50:46
【问题描述】：

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)

在我的 Android 代码中，我有很多图像必须显示到不同的片段中。其中一些存储在 assets 文件夹中，其他来自 http 请求。出于这个原因，我实现了图像缓存，以免违反 java.lang.OutOfMemoryError，但这个错误似乎仍然存在。我该如何解决这个问题？下面是我的图像缓存实现。

图像加载器

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();
}
}

文件缓存

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();
}

}

内存缓存

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();
}
}

实用程序

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){}
}
}

【问题讨论】：

你知道这是来自你自己的图像吗？堆栈跟踪看起来像是源自 Google 地图代码。
@Gus 是的，但是看看前 4 行....我想很快就结束了内存无法分配地图
重新考虑接受正确答案:)

标签： android performance memory-leaks out-of-memory image-caching

【解决方案1】：

在你的清单文件中添加这个标签。

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

【讨论】：

【解决方案2】：

OutOfMemoryError 是 android 在处理位图时最常见的问题。当由于内存空间不足而无法分配对象并且垃圾收集器无法释放一些空间时，Java 虚拟机 (JVM) 会引发此错误。

正如 Aleksey 所说，您可以在清单文件中添加以下实体 android:hardwareAccelerated="false" ， android:largeHeap="true" 它适用于某些环境。

<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">

【讨论】：

【解决方案3】：

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

【讨论】：

【解决方案4】：

试试这个可能对你有帮助在你的清单文件中添加这个标签。

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

它将为您的应用分配大堆

【讨论】：

现在添加这个似乎工作...谢谢
要明确：largeHeap 进入application 标签。此外，它不应该用作内存泄漏的修复程序，而只能在您的应用程序确实需要更多内存时使用。见developer.android.com/training/articles/memory.html
此解决方案不正确。您的应用程序中存在内存泄漏。此解决方案只会延迟问题，但不会修复泄漏。
这真的很有用。
对“无法分配 0 个空闲字节和 3GB 直到 OOM 的 24 字节分配失败”类型的错误也有帮助

【解决方案5】：

你可以试试这个代码....

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

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

【讨论】：

【解决方案6】：

高效加载大型位图： http://developer.android.com/training/displaying-bitmaps/load-bitmap.html

缓存位图： http://developer.android.com/training/displaying-bitmaps/cache-bitmap.html

尝试调整图像大小并在使用后回收位图。

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)
 }
 }

【讨论】：

你能看看这个吗？ stackoverflow.com/questions/29990186/…

【解决方案7】：

这是因为内存不足，图像文件很大，为了解决这个问题，在你的类中添加这个方法：

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;
            }

然后在你使用这个的地方调用这个方法：

Bitmap b = decodeFile(f);

使用这个：

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

【讨论】：

如果我的图像大于 1280、720 怎么办？此外，我主要从 assets 文件夹和 http 请求中获取图像......这个类别有什么变化？
@FrancescoLombardo，这解决了大图像的问题，它唯一的限制是它会将大图像制作为1280x720。
我使用此分辨率解决了我的错误，如果您的设备可以支持大于 1280x720，那么您可以尝试使用自定义 rwsolution 调用此方法
谢谢！从资产文件夹解码位图我必须做哪些更改？
我已经实施了您的解决方案，谢谢！但是我遇到了另一个烦人的问题，你能看看这个吗？ stackoverflow.com/questions/29990186/…

【解决方案8】：

尝试在将图像加载到内存之前以及不需要使用此图像对象时手动调用 System.gc()。

【讨论】：

System.gc() 即使手动调用也可能不会被调用。即使它被调用，它也会冻结应用程序一秒钟。所以这是一个非常糟糕的建议。