How to assign key to bitmap using HashMap?

Question

In global definition I have declared: private HashMap<String, Bitmap> map = new HashMap<String, Bitmap>();

In other part of my code, I connect to server and get my required info. Two of then are image address (url) and image id. after that I download image and I want to assign it its own Id. This is my code:

private LinkedList<Bitmap> getFlagImages() {
    InputStream is= null;
    LinkedList<Bitmap> llBitmap = new LinkedList<Bitmap>();


    for(int i = 0; i < flag.getTeamLogo44x44().size(); i++) {
        String urlstr = flag.getTeamLogo44x44().get(i);

        try {
            HttpGet httpRequest   = new HttpGet(urlstr);
            HttpClient httpclient = new DefaultHttpClient();
            HttpResponse response = (HttpResponse) httpclient.execute(httpRequest);

            HttpEntity entity = response.getEntity();
            BufferedHttpEntity bufHttpEntity = new BufferedHttpEntity(entity);
            is = bufHttpEntity.getContent();
            Bitmap bm = BitmapFactory.decodeStream(is);

            llBitmap.add(bm);
            map.put(flag.getTeamId().get(i), bm);  // *Crash happens here

        }catch ( MalformedURLException e ){
            Log.d( "RemoteImageHandler", "Invalid URL passed" + urlstr );
        }catch ( IOException e ){
            Log.d( "RemoteImageHandler", "fetchImage IO exception: " + e );
        }finally{
            if(is != null) {
                try{
                    is.close();
                } catch(IOException e) {}
            }
        }
    }

    return llBitmap;        
}

When I run, the application crashes and logcat shows Null Pointer Exception and points to line map.put(flag.getTeamId().get(i), bm);

Any suggestion would be appreciated.

// Update, Also I used map.put(flag.getTeamId().get(i), Bitmap.createBitmap(bm)); but the result was same.

Please include a stack trace. In all liklihood, `flag.getTeamId().get(i)` is returning `null`. — cheeken, May 25 '12 at 02:55
@cheeken - `HashMap` allows the `null` key though. My guess would be `getTeamId()` is returning `null`. — Paul Bellora, May 25 '12 at 03:03

score 0 · Answer 1 · answered May 25 '12 at 03:02

0

Looks like flag.getTeamId() is null, or, like cheeken said, flag.getTeamId.get(i) is null

You could try using assertions like assert (flag.getTeamId() != null) assert (flag.getTeamId().get(i) != null)

Now run your jvm with the -ea flag (short for enable assertions)

answered May 25 '12 at 03:02

user3001

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i'm sure it has result because i checked it. Now the problem solved with changing mentioned line with map.put(flag.getTeamId().get(i), Bitmap.createBitmap(bm, 0, 0, bm.getWidth(), bm.getHeight())); Thanks for your help – Hesam May 25 '12 at 03:06

score 0 · Answer 2 · answered May 25 '12 at 03:04

0

I changed

map.put(flag.getTeamId().get(i), bm);

to

map.put(flag.getTeamId().get(i), Bitmap.createBitmap(bm, 0, 0, bm.getWidth(), bm.getHeight()));

and its ok, now. but I have no idea why the first one didn't work!!!

answered May 25 '12 at 03:04

Hesam

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That doesn't make sense - the value that is `put` shouldn't matter, even if it was `null`. – Paul Bellora May 25 '12 at 03:07

score 0 · Answer 3 · answered May 25 '12 at 03:07

0

It looks like you found your answer. However, you might consider having your map take WeakReference<Bitmap> as a value instead. That is,

Map<Integer, WeakReference<Bitmap>>

By keeping a weak reference, you ensure garbage collection will work as expected later on.

answered May 25 '12 at 03:07

Alex Lockwood

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Thanks Alex. Key comes from server, I'm not sure it is always integer. Thank you for your advice. – Hesam May 25 '12 at 03:12
Well unless the server is sending you a `BigInteger`, I think you should be OK :D – Alex Lockwood May 25 '12 at 03:16

How to assign key to bitmap using HashMap?

3 Answers3