我正在爲Android編寫一個應用程序,該應用程序從SHOUTcast mp3流中獲取元數據。我正在使用我在網上發現的一個非常漂亮的課程,稍作修改,但我仍然遇到2個問題。使用IcyStreamMeta從SHOUTcast獲取元數據
1)我必須連續ping服務器以使用TimerTask更新元數據。我不喜歡這種方法,但這是我所能想到的。
2)當我的應用程序正在運行時,有一噸垃圾收集。刪除TimerTask擺脫了垃圾收集問題,所以我不確定是否我做錯了或者這是正常的。
這裏是我使用的類:
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;
}
}
這裏是我的定時器:
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);
}
的任何援助大部分升值!
我移動了'Iicy = new IcyStreamMeta(new URL(stationUrl))''我的'onCreate()'方法並修復了垃圾回收問題。但是現在我的元數據沒有更新... – Karai17 2012-02-11 18:19:44
Alrighty,我在'setText()'之前調用'icy.refreshMeta()'並且我的元數據再次刷新,但每個刷新間隔都有垃圾收集。這是壞事嗎?它會消耗電池壽命嗎? – Karai17 2012-02-11 19:34:35
http://pastie.org/3362717 – Karai17 2012-02-11 20:05:09