Retrieving metadata from SHOUTcast using IcyStreamMeta

Question

I am writing an Android application that captures metadata from SHOUTcast mp3 streams. I am using a pretty cool class that I found on the Internet that I changed a bit, but I still have two problems.

1) I have to constantly ping the server to update metadata using TimerTask. I do not like this approach, but that’s all I could think of.

2) While my application is running, there is a metric ton of garbage. Removing TimerTask got rid of the garbage collection problem, so I'm not sure if I'm just doing it wrong or if it's ok.

Here is the class I'm using:

public class IcyStreamMeta {
    protected URL streamUrl;
    private Map<String, String> metadata;
    private boolean isError;

public IcyStreamMeta(URL streamUrl) {
    setStreamUrl(streamUrl);

    isError = false;
}

/**
 * Get artist using stream title
 *
 * @return String
 * @throws IOException
 */
public String getArtist() throws IOException {
    Map<String, String> data = getMetadata();

    if (!data.containsKey("StreamTitle"))
        return "";

    try {
        String streamTitle = data.get("StreamTitle");
        String title = streamTitle.substring(0, streamTitle.indexOf("-"));
        return title.trim();
    }catch (StringIndexOutOfBoundsException e) {
        return "";
    }
}

/**
 * Get title using stream title
 *
 * @return String
 * @throws IOException
 */
public String getTitle() throws IOException {
    Map<String, String> data = getMetadata();

    if (!data.containsKey("StreamTitle"))
        return "";

    try {
        String streamTitle = data.get("StreamTitle");
        String artist = streamTitle.substring(streamTitle.indexOf("-")+1);
        return artist.trim();
    } catch (StringIndexOutOfBoundsException e) {
        return "";
    }
}

public Map<String, String> getMetadata() throws IOException {
    if (metadata == null) {
        refreshMeta();
    }

    return metadata;
}

public void refreshMeta() throws IOException {
    retreiveMetadata();
}

private void retreiveMetadata() throws IOException {
    URLConnection con = streamUrl.openConnection();
    con.setRequestProperty("Icy-MetaData", "1");
    con.setRequestProperty("Connection", "close");
    //con.setRequestProperty("Accept", null);
    con.connect();

    int metaDataOffset = 0;
    Map<String, List<String>> headers = con.getHeaderFields();
    InputStream stream = con.getInputStream();

    if (headers.containsKey("icy-metaint")) {
        // Headers are sent via HTTP
        metaDataOffset = Integer.parseInt(headers.get("icy-metaint").get(0));
    } else {
        // Headers are sent within a stream
        StringBuilder strHeaders = new StringBuilder();
        char c;
        while ((c = (char)stream.read()) != -1) {
            strHeaders.append(c);
            if (strHeaders.length() > 5 && (strHeaders.substring((strHeaders.length() - 4), strHeaders.length()).equals("\r\n\r\n"))) {
                // end of headers
                break;
            }
        }

        // Match headers to get metadata offset within a stream
        Pattern p = Pattern.compile("\\r\\n(icy-metaint):\\s*(.*)\\r\\n");
        Matcher m = p.matcher(strHeaders.toString());
        if (m.find()) {
            metaDataOffset = Integer.parseInt(m.group(2));
        }
    }

    // In case no data was sent
    if (metaDataOffset == 0) {
        isError = true;
        return;
    }

    // Read metadata
    int b;
    int count = 0;
    int metaDataLength = 4080; // 4080 is the max length
    boolean inData = false;
    StringBuilder metaData = new StringBuilder();
    // Stream position should be either at the beginning or right after headers
    while ((b = stream.read()) != -1) {
        count++;

        // Length of the metadata
        if (count == metaDataOffset + 1) {
            metaDataLength = b * 16;
        }

        if (count > metaDataOffset + 1 && count < (metaDataOffset + metaDataLength)) {              
            inData = true;
        } else {                
            inData = false;             
        }               
        if (inData) {               
            if (b != 0) {                   
                metaData.append((char)b);               
            }           
        }               
        if (count > (metaDataOffset + metaDataLength)) {
            break;
        }

    }

    // Set the data
    metadata = IcyStreamMeta.parseMetadata(metaData.toString());

    // Close
    stream.close();
}

public boolean isError() {
    return isError;
}

public URL getStreamUrl() {
    return streamUrl;
}

public void setStreamUrl(URL streamUrl) {
    this.metadata = null;
    this.streamUrl = streamUrl;
    this.isError = false;
}

public static Map<String, String> parseMetadata(String metaString) {
    Map<String, String> metadata = new HashMap<String, String>();
    String[] metaParts = metaString.split(";");
    Pattern p = Pattern.compile("^([a-zA-Z]+)=\\'([^\\']*)\\'$");
    Matcher m;
    for (int i = 0; i < metaParts.length; i++) {
        m = p.matcher(metaParts[i]);
        if (m.find()) {
            metadata.put((String)m.group(1), (String)m.group(2));
        }
    }

    return metadata;
}

}

And here is my timer:

private void getMeta() {
    timer.schedule(new TimerTask() {
        public void run() {
            try {
                icy = new IcyStreamMeta(new URL(stationUrl));

                runOnUiThread(new Runnable() {
                     public void run() {
                         try {
                             artist.setText(icy.getArtist());
                             title.setText(icy.getTitle());
                         } catch (IOException e) {
                             e.printStackTrace();
                         } catch (StringIndexOutOfBoundsException e) {
                             e.printStackTrace();
                         }
                     }
                });
            } catch (MalformedURLException e) {
                e.printStackTrace();
            }

        }
    },0,5000);

}

Thanks so much for any help!

Answer 1

IcyStreamMeta 7.html, SHOUTcast. , , .

TimerTask, . GC, 7.html .:)