Android应用中的Java.Lang.OutOfMemoryError

Question

I had an app working fine and then all of a sudden it started force closing/crashing and the logcat says it's an out of memory error.

The logcat is below:

04-27 10:53:05.366 8899-8899/cct.mad.lab E/AndroidRuntime: FATAL EXCEPTION: main
                                                       Process: cct.mad.lab, PID: 8899
                                                       java.lang.OutOfMemoryError
                                                           at android.graphics.BitmapFactory.nativeDecodeAsset(Native Method)
                                                           at android.graphics.BitmapFactory.decodeStream(BitmapFactory.java:587)
                                                           at android.graphics.BitmapFactory.decodeResourceStream(BitmapFactory.java:422)
                                                           at android.graphics.BitmapFactory.decodeResource(BitmapFactory.java:445)
                                                           at android.graphics.BitmapFactory.decodeResource(BitmapFactory.java:475)
                                                           at cct.mad.lab.Sprite.<init>(Sprite.java:37)
                                                           at cct.mad.lab.GameView.createSprites(GameView.java:63)
                                                           at cct.mad.lab.GameView.surfaceCreated(GameView.java:86)
                                                           at android.view.SurfaceView.updateWindow(SurfaceView.java:572)
                                                           at android.view.SurfaceView.access$000(SurfaceView.java:86)
                                                           at android.view.SurfaceView$3.onPreDraw(SurfaceView.java:175)
                                                           at android.view.ViewTreeObserver.dispatchOnPreDraw(ViewTreeObserver.java:847)
                                                           at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1871)
                                                           at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1000)
                                                           at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5670)
                                                           at android.view.Choreographer$CallbackRecord.run(Choreographer.java:761)
                                                           at android.view.Choreographer.doCallbacks(Choreographer.java:574)
                                                           at android.view.Choreographer.doFrame(Choreographer.java:544)
                                                           at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:747)
                                                           at android.os.Handler.handleCallback(Handler.java:733)
                                                           at android.os.Handler.dispatchMessage(Handler.java:95)
                                                           at android.os.Looper.loop(Looper.java:136)
                                                           at android.app.ActivityThread.main(ActivityThread.java:5017)
                                                           at java.lang.reflect.Method.invokeNative(Native Method)
                                                           at java.lang.reflect.Method.invoke(Method.java:515)
                                                           at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
                                                           at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
                                                           at dalvik.system.NativeStart.main(Native Method)

The sprite class is where it appears the problem is being caused (at line 37). It is a png image. The section of code, with line 37 being the third line down, is below:

public Sprite(GameView gameView) {
    this.gameView = gameView;
    spritebmp = BitmapFactory.decodeResource(gameView.getResources(),
            R.drawable.bad4);
    this.bmp_width = spritebmp.getWidth() / BMP_COLUMNS;
    this.bmp_height = spritebmp.getHeight() / BMP_ROWS;
    xSpeed = random.nextInt(15) + 1;
    ySpeed = random.nextInt(15) + 1;
    x = random.nextInt(gameView.getWidth() - bmp_width);
    y = random.nextInt(gameView.getHeight() - bmp_height);

I've tried adding the below to the manifest but with no success:

android:largeHeap="true"

I'm not quite sure what to try next and this is for an assignment. It was going so well but if I can't figure this out I won't have anything to submit.

All help and advice greatly appreciated.

Thanks

EDIT: Below I have added the entire sprite class as from what people are saying, some things need to change in here:

package cct.mad.lab;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.media.SoundPool;
import android.support.v7.app.AppCompatActivity;

import java.util.Random;


public class Sprite extends AppCompatActivity {

private static final int BMP_ROWS = 4;
private static final int BMP_COLUMNS = 3;
//x,y position of sprite - initial position (0,50)
private int x = 0;
private int y = 0;
private int xSpeed = 5;//Horizontal increment of position (speed)
private int ySpeed = 5;// Vertical increment of position (speed)
private GameView gameView;
private Bitmap spritebmp;
private int currentFrame = 0;
//Width and Height of the Sprite image
private int bmp_width;
private int bmp_height;
// Needed for new random coordinates.
private Random random = new Random();

private SoundPool mySound;
int zapSoundId;


public Sprite(GameView gameView) {
    this.gameView = gameView;
    spritebmp = BitmapFactory.decodeResource(gameView.getResources(),
            R.drawable.bad3);
    this.bmp_width = spritebmp.getWidth() / BMP_COLUMNS;
    this.bmp_height = spritebmp.getHeight() / BMP_ROWS;
    xSpeed = random.nextInt(15) + 1;
    ySpeed = random.nextInt(15) + 1;
    x = random.nextInt(gameView.getWidth() - bmp_width);
    y = random.nextInt(gameView.getHeight() - bmp_height);

    //mySound = new SoundPool(1, AudioManager.STREAM_MUSIC, 0);
    //zapSoundId = mySound.load(this, R.raw.zap, 1);


}

public Sprite(GameView gameView, Bitmap bmp) {

}

//update the position of the sprite
public void update() {
    x = x + xSpeed;
    y = y + ySpeed;
    bounce();
    //y = random.nextInt(gameView.getWidth());
    //wrapAround(); //Adjust motion of sprite.
}

private void bounce() {
    if (x <= 0 || x >= gameView.getWidth() ) {
        xSpeed = xSpeed * -1;
    }
    if (y <= 0 || y >= gameView.getHeight() ) {
        ySpeed = ySpeed * -1;
    }
    currentFrame = ++currentFrame % BMP_COLUMNS;
    /*if (x > gameView.getWidth() - spritebmp.getWidth() - xSpeed) {
        xSpeed = -5;
        if (x + xSpeed < 0) {
            xSpeed = 5;
        }
        x = x + xSpeed;
    }
    if (y > gameView.getHeight() - spritebmp.getHeight() - ySpeed) {
        ySpeed = -5;
        if (y + ySpeed < 0) {
            ySpeed = 5;
        }
        y = y + ySpeed;
    }*/
}

public void draw(Canvas canvas) {

    update();
    int srcX = currentFrame * bmp_width;
    int srcY;
    if (xSpeed > 0) {
        srcY = 0 * bmp_height;
    }
    else {
        srcY = 1 * bmp_height;
    }
    // Create Rect around the source image to be drawn
    Rect src = new Rect(srcX, srcY, srcX + bmp_width, srcY + bmp_height);
    // Rect for destination image
    Rect dst = new Rect(x, y, x + bmp_width, y + bmp_height);
    //
    // Draw the image frame
    canvas.drawBitmap(spritebmp, src, dst, null);

}


// Checks if the sprite was touched
public boolean wasItTouched(float ex, float ey) {
    boolean touched = false;
    if ((x <= ex) && (ex < x + bmp_width) &&
            (y <= ey) && (ey < y + bmp_height)) {
        touched = true;
        //mySound.play(zapSoundId, 1, 1, 1, 0, 1);


    }
    //

    return touched;
}

}

EDIT: I would also like to point out that the sprites I use are all less than 5kb each and I have an array that replicates it about 8 times, so it's hardly a massive image that would take up so much memory

Answer 1

Please refer to this tutorial: https://developer.android.com/topic/performance/graphics/load-bitmap.html

In summary they first read the size of the bitmap. Then they subsample the file.

Edit: Now I see that your file is very small. When it comes to games - please make sure that you load the resource into memory just once and then reuse it.

Also, when you're done using the bitmap, call .recycle() .

Ideally you should have some asset manager object that loads resources and keeps them for as long as needed. And any Sprite must ask for the already loaded resource instead of reading a new one everytime.

Edit 2: Ok, let's explain it a bit further. If it's a simple game, and I assume it is, create a class that will handle loading of your assets. Let's call it AssetManager .

Then let's make AssetManager be instantiated only once (a singleton) by your game "engine" (whatever handles the game loop). Prepare some kind of mapping, you can read it from file or you can hardcode it for now (just for the sake of simplicity of this example).

let the AssetManager hold this map and another one for bitmaps.

Map<String, Integer> spriteRes;
Map<String, Bitmap> spriteBmps;

and then in Sprite take a String argument describing what bitmap to use, eg

Sprite ghost = new Sprite("ghost");

Every game runs in a loop and has a draw function. Then for every Sprite that's in the scene all you need to do is to take the name of the resource and retrieve the Bitmap from the AssetManager . If it doesn't have it stored in spriteBmps , then call Bitmap.decodeResource() and store it. You can also preload all assets at the start of your program.

class AssetManager {
    Map<String, Integer> spriteRes;
    Map<String, Bitmap> spriteBmps;

    Bitmap getBitmap(GameView gameView, String key) {
        if (spriteBmps.containsKey(key) && spriteBmps.get(key) != null)
            return spriteBmps.get(key);
        Bitmap bitmap = BitmapFactory.decodeResource(gameView.getResources(), R.drawable.bad3)
        spriteBmps.put(key, bitmap);
        return bitmap;
    }
}

That way you hold just one Bitmap for every object type and only tell where to render it on the canvas.

When to call .recycle() ? When you no longer need the bitmap. It depends on your case and architecture.

Answer 2

The problem was with my initial for loop. I mistakenly made it so that it was never ending and always creating a new sprite in my GameView class. I fixed that and it now works fine