Reputation: 714
I'm using lazy loading images based on this question. I'm implementing a search function that, when the user enters a keyword, the application will do a request and parse the result using SAX and then place the data into a ListView. Sometimes the images can be loaded into ImageViews of the ListView rows but sometimes it will load only one or two images and the application crashes.
Below is my LogCat output:
05-16 16:37:37.414: ERROR/AndroidRuntime(620): FATAL EXCEPTION: Thread-11
05-16 16:37:37.414: ERROR/AndroidRuntime(620): java.lang.NullPointerException
05-16 16:37:37.414: ERROR/AndroidRuntime(620): at com.TPLibrary.Search.ImageLoader.getBitmap(ImageLoader.java:71)
05-16 16:37:37.414: ERROR/AndroidRuntime(620): at com.TPLibrary.Search.ImageLoader.access$0(ImageLoader.java:68)
05-16 16:37:37.414: ERROR/AndroidRuntime(620): at com.TPLibrary.Search.ImageLoader$PhotosLoader.run(ImageLoader.java:173)
Below is where the errors are occuring at:
private Bitmap getBitmap(String url) { // line 68
//I identify images by hashcode. Not a perfect solution, but ok for the demo
String filename = String.valueOf(url.hashCode()); // line 71
File f = new File(cacheDir, filename);
//from SD cache
Bitmap b = decodeFile(f);
if (b != null)
return b;
//from web
try {
Bitmap bitmap = null;
InputStream is = new URL(url).openStream();
OutputStream os = new FileOutputStream(f);
Utils.CopyStream(is, os);
os.close();
bitmap = decodeFile(f);
return bitmap;
} catch (Exception ex){
ex.printStackTrace();
return null;
}
}
class PhotosLoader extends Thread {
public void run() {
try {
while(true)
{
//thread waits until there are any images to load in the queue
if (photosQueue.photosToLoad.size() == 0)
synchronized(photosQueue.photosToLoad) {
photosQueue.photosToLoad.wait();
}
if (photosQueue.photosToLoad.size() != 0) {
PhotoToLoad photoToLoad;
synchronized(photosQueue.photosToLoad) {
photoToLoad=photosQueue.photosToLoad.pop();
}
Bitmap bmp = getBitmap(photoToLoad.url); // line 173
cache.put(photoToLoad.url, bmp);
Object tag = photoToLoad.imageView.getTag();
if (tag != null && ((String)tag).equals(photoToLoad.url)){
BitmapDisplayer bd =
new BitmapDisplayer(bmp, photoToLoad.imageView);
Activity a = (Activity)photoToLoad.imageView.getContext();
a.runOnUiThread(bd);
}
}
if (Thread.interrupted())
break;
}
} catch (InterruptedException e) {
//allow thread to exit
}
}
}
EDIT
I have tracked down the NullPointerException
that comes from the PhotoToLoad
class below:
private class PhotoToLoad {
public String url;
public ImageView imageView;
public PhotoToLoad(String u, ImageView i) {
url = u;
imageView = i;
}
}
How can I solve the problem?
Upvotes: 0
Views: 1005
Reputation: 7388
It seems that you pass null
to this method. Make sure that you handle null
appropriately, or make sure you don't pass null
there (first is better ;)).
String filename=String.valueOf(url.hashCode());
So, url
is null
at this point. So Either you integrate a check like
if (url == null) {
Log.w("null has been passed to getBitmap()");
return null;
}
or you have a look on every call where you pass null
to this method making it crash.
Upvotes: 3
Reputation: 10632
Remove return null from your catch() block because this might be throwing an Exception and the Bitmap is getting NULL object.
Upvotes: 0