Eu preciso de uma maneira de fazer upload de um arquivo e enviá-lo para a página php ...

Minha página php é:

<?php 
$maxsize = 10485760;
$array_estensioni_ammesse=array('.tmp');
$uploaddir = 'uploads/';
if (is_uploaded_file($_FILES['file']['tmp_name']))
{
    if($_FILES['file']['size'] <= $maxsize)
    {
        $estensione = strtolower(substr($_FILES['file']['name'], strrpos($_FILES['file']['name'], "."), strlen($_FILES['file']['name'])-strrpos($_FILES['file']['name'], ".")));
        if(!in_array($estensione, $array_estensioni_ammesse))
        {
            echo "File is not valid!\n";
        }
        else
        {
            $uploadfile = $uploaddir . basename($_FILES['file']['name']); 
            echo "File ". $_FILES['file']['name'] ." uploaded successfully.\n"; 
            if (move_uploaded_file($_FILES['file']['tmp_name'], $uploadfile))
            {
                echo "File is valid, and was successfully moved.\n";
            } 
            else 
                print_r($_FILES); 
        }
    }
    else
        echo "File is not valid!\n";
}
else
{ 
    echo "Upload Failed!!!"; 
    print_r($_FILES);
} 
?>

e eu uso esse código java no meu aplicativo de desktop:

HttpURLConnection httpUrlConnection = (HttpURLConnection)new URL("http://www.mypage.org/upload.php").openConnection();
        httpUrlConnection.setDoOutput(true);
        httpUrlConnection.setRequestMethod("POST");
        OutputStream os = httpUrlConnection.getOutputStream();
        Thread.sleep(1000);
        BufferedInputStream fis = new BufferedInputStream(new FileInputStream("tmpfile.tmp"));

        for (int i = 0; i < totalByte; i++) {
            os.write(fis.read());
            byteTrasferred = i + 1;
        }

        os.close();
        BufferedReader in = new BufferedReader(
                new InputStreamReader(
                httpUrlConnection.getInputStream()));

        String s = null;
        while ((s = in.readLine()) != null) {
            System.out.println(s);
        }
        in.close();
        fis.close();

Mas recebo sempre o "Upload Failed !!!" mensagem.