Question

I am using this Utility

public class Util_ImageLoader {
public static Bitmap _bmap;

Util_ImageLoader(String url) {
    HttpConnection connection = null;
    InputStream inputStream = null;
    EncodedImage bitmap;
    byte[] dataArray = null;

    try {
        connection = (HttpConnection) Connector.open(url + Util_GetInternet.getConnParam(), Connector.READ,
                true);
        inputStream = connection.openInputStream();
        byte[] responseData = new byte[10000];
        int length = 0;
        StringBuffer rawResponse = new StringBuffer();
        while (-1 != (length = inputStream.read(responseData))) {
            rawResponse.append(new String(responseData, 0, length));
        }
        int responseCode = connection.getResponseCode();
        if (responseCode != HttpConnection.HTTP_OK) {
            throw new IOException("HTTP response code: " + responseCode);
        }

        final String result = rawResponse.toString();
        dataArray = result.getBytes();
    } catch (final Exception ex) {
    }

    finally {
        try {
            inputStream.close();
            inputStream = null;
            connection.close();
            connection = null;
        } catch (Exception e) {
        }
    }

    bitmap = EncodedImage
            .createEncodedImage(dataArray, 0, dataArray.length);
    int multH;
    int multW;
    int currHeight = bitmap.getHeight();
    int currWidth = bitmap.getWidth();
    multH = Fixed32.div(Fixed32.toFP(currHeight), Fixed32.toFP(currHeight));// height
    multW = Fixed32.div(Fixed32.toFP(currWidth), Fixed32.toFP(currWidth));// width
    bitmap = bitmap.scaleImage32(multW, multH);

    _bmap = bitmap.getBitmap();
}

public Bitmap getbitmap() {
    return _bmap;
}
}

When I call it in a listfield which contains 10 childs, then the log keeps saying failed to allocate timer 0: no slots left.

This means the memory is being used up and no more memory to allocate again and as a result my main screen cannot start.

Answer 1

At the same time you have the following objects in memory:

    // A buffer of about 10KB
    byte[] responseData = new byte[10000];

    // A string buffer which will grow up to the total response size
    rawResponse.append(new String(responseData, 0, length));

    // Another string the same length that string buffer
    final String result = rawResponse.toString();

    // Now another buffer the same size of the response.        
    dataArray = result.getBytes();

It total, if you downloaded n ascii chars, you have simultaneously 10KB, plus 2*n bytes in the first unicode string buffer, plus 2*n bytes in the result string, plus n bytes in dataArray. If I’m not wrong, that sums up to 5n + 10k. There’s room for optimization.

Some improvements would be:

• Check response code first, and then read the stream if response code is HTTP 200. No need to read if server returned an error.
• Get rid of strings. No need to convert to string if after that you are converting again to bytes.
• If images are large, don’t store them in RAM while downloading. Instead, open a FileOutputStream and write to a temporary file as you read from input stream. Then, if temporary images are still large enough to be displayed, downscale them.