获取元数据使用IcyStreamMeta Shoutcast一样数据、IcyStreamMeta、Shoutcast
我写了Android的一个应用程序，抓取元数据从Shoutcast一样的mp3流。我使用的是pretty的漂亮级我在网上发现，我稍微修改，但我仍然有两个问题。
I am writing an app for Android that grabs meta data from SHOUTcast mp3 streams. I am using a pretty nifty class I found online that I slightly modified, but I am still having 2 problems.
1）我要不断地ping服务器更新使用的TimerTask的元数据。我不喜欢这种方式，但它是所有我能想到的。
1) I have to continuously ping the server to update the metadata using a TimerTask. I am not fond of this approach but it was all I could think of.
2）有一公吨的垃圾收集，而我的应用程序正在运行。卸下的TimerTask摆脱了垃圾回收的问题，所以我不知道如果我只是做是错误的，或者如果这是正常的。
2) There is a metric tonne of garbage collection while my app is running. Removing the TimerTask got rid of the garbage collection issue so I am not sure if I am just doing it wrong or if this is normal.
下面是我使用的类：
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's 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's 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;
}
}
这里是我的定时器：
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);
}
许多AP preciation的任何援助！
Much appreciation for any assistance!
推荐答案
我把它换成我的程序的IcyStreamMeta类，并正在逐渐从7.html文件，它是Shoutcast一样规范的一部分的元数据。远不如数据的使用和所有的，所以我觉得这是一个更好的选择。
I've replaced the IcyStreamMeta class in my program and am getting the meta data from the 7.html file that is a part of the SHOUTcast spec. Far less data usage and all that so I feel it is a better option.
我仍在使用一个TimerTask，这是可以接受的。几乎没有任何的GC任何更多的，我很高兴使用7.html和一点点正则表达式。 ：）
I am still using the TimerTask, which is acceptable. There is practically no GC any more and I am happy with using 7.html and a little regex. :)
