Continously extract StreamTitle (MP3 metadata) from SHOUTcast / IceCast audio streaming

IceCastMetaData.java

import java.io.IOException;
import java.io.InputStream;
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpHeaders;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse.BodyHandlers;
import java.nio.charset.StandardCharsets;

/**
 * Uses java.net.http from Java 11
 */
public class IceCastMetaData {
    
    static final int DEFAULT_METADATA_INTERVAL = 8192;

    
    public static void main(String[] args) {
        
        URI streamUri = URI.create("https://radioserver/");
        
        HttpClient client = HttpClient.newBuilder().build();
        HttpRequest request = HttpRequest.newBuilder()
            .GET()
            .uri(streamUri)
            .header("Icy-MetaData", "1") // instruct the server, that we want the metadata
            .build();
        
        
        // This could certainly also be done with using Apache HttpClient, 
        // instead of the built-in Java 11 HttpClient
        client.sendAsync(request, BodyHandlers.ofInputStream())
            .thenAccept(resp -> {
                
                // Retrieve the headers of the server response
                HttpHeaders headers = resp.headers();
                
                // "icy-metaint" = how often the metadata is sent in the stream
                // This might not be sent by the server, and then it defaults to DEFAULT_METADATA_INTERVAL
                int metaInterval = headers.firstValue("icy-metaint").map(Integer::parseInt).orElse(DEFAULT_METADATA_INTERVAL);
                
                
                // Get the InputStream of the audio stream
                try (InputStream stream = resp.body()) {
                    
                    while (true) {
                        // Read a chunk of music data (as we are not using it, just skipping)
                        stream.skipNBytes(metaInterval);
                        
                        // Extract the metadata from the chunk
                        String meta = readMetaData(stream);
                        
                        // See if we got something useful from this current chunk
                        if (!meta.isEmpty() && meta.startsWith("StreamTitle")) {
                            
                            // If we got some metadata, then it will be on the form: "StreamTitle='<song title>';"
                            // That is, it always starts with "StreamTitle='" and ends with "';"
                            System.out.println("Now playing :: "  +  meta.substring("StreamTitle=".length(), meta.indexOf(';')));
                        }
                        
                    }
                    
                } catch (IOException e) {
                    e.printStackTrace();
                }
            })
            .join();
    }
    
    private static String readMetaData(InputStream stream) throws IOException {
        // The next byte after a music chunk indicates the length of the metadata
        int length = stream.read();
        if (length < 1) return ""; // no new metadata is present (the song is playing)
        
        // Multiply by 16 to get the number of bytes, that holds the data
        int metaChunkSize = length * 16;
        byte[] metaChunk = stream.readNBytes(metaChunkSize);
        return new String(metaChunk, 0, metaChunkSize, StandardCharsets.ISO_8859_1);
    }
}