image loading

[csergiu77]

I work on application that among other things download some images from a server.

Strange but on nokia 6233 images are loaded quite fast 2,3 sec.

N73 - 85-90 sec
E61 - 110 sec (using 3G)
E51 - 25-30 sec (using wireless)
E51 - 35-55 sec (3G connection)


On any SE i tried it works very very fast ,almost instant loading !!!!

ANy ideea why ?

[Tiger79]

well the S60's are symbian and they run a KVM, whilst the series 40 are native java ?
thats just me guessing...

[grahamhughes]

It may depend on your code.

Reading one byte at a time tends to be really slow on some devices.

public static byte[] read(InputStream in, int contentLength) throws IOException {
    byte[] b = new byte[contentLength];
    for (int i = 0; i < contentLength; i++) {
        // don't do this!  Slow!!
        b[i] = (byte)in.read();
    }
    return b;
}

Reading into an array is much better. Note that you can't just call read() and expect everything to be OK. You must check the return value to see how many bytes were actually read.

public static byte[] read(InputStream in, int contentLength) throws IOException {
    byte[] b = new byte[contentLength];
    int readSoFar = 0;
    while (readSoFar < contentLength) {
        readSoFar += in.read(b, readSoFar, contentLength - readSoFar);
    }
    return b;
}

I'm surprised this would make S60's slower, but if you're using code like the first example, you should definitely switch.

(The same applies to reading resource files from the JAR.)

Cheers,
Graham.