I have a 2.67 GHz Celeron processor, 1.21 GB of RAM on a x86 Windows XP Professional machine. My understanding is that the Android emulator should start fairly quickly on such a machine, but for me it does not. I have followed all instructions in setting up the IDE, SDKs, JDKs and such and have had some success in staring the emulator quickly but is very particulary. How can I, if possible, fix this problem?
Afaik, sending ICMP ECHO requests needs root (i.e. the app that does it needs to be setuid) - and that's not currently possible in "stock" Android (hell, even the InetAddress#isReachable() method in Android is a joke that doesn't work according to spec).
ReplyDeleteA very basic example using /usr/bin/ping & Process - reading the ping results, using an AsyncTask:
public class PingActivity extends Activity {
PingTask mTask;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
@Override
protected void onResume() {
super.onResume();
mTask = new PingTask();
// Ping the host "android.com"
mTask.execute("android.com");
}
@Override
protected void onPause() {
super.onPause();
mTask.stop();
}
class PingTask extends AsyncTask<String, Void, Void> {
PipedOutputStream mPOut;
PipedInputStream mPIn;
LineNumberReader mReader;
Process mProcess;
TextView mText = (TextView) findViewById(R.id.text);
@Override
protected void onPreExecute() {
mPOut = new PipedOutputStream();
try {
mPIn = new PipedInputStream(mPOut);
mReader = new LineNumberReader(new InputStreamReader(mPIn));
} catch (IOException e) {
cancel(true);
}
}
public void stop() {
Process p = mProcess;
if (p != null) {
p.destroy();
}
cancel(true);
}
@Override
protected Void doInBackground(String... params) {
try {
mProcess = new ProcessBuilder()
.command("/system/bin/ping", params[0])
.redirectErrorStream(true)
.start();
try {
InputStream in = mProcess.getInputStream();
OutputStream out = mProcess.getOutputStream();
byte[] buffer = new byte[1024];
int count;
// in -> buffer -> mPOut -> mReader -> 1 line of ping information to parse
while ((count = in.read(buffer)) != -1) {
mPOut.write(buffer, 0, count);
publishProgress();
}
out.close();
in.close();
mPOut.close();
mPIn.close();
} finally {
mProcess.destroy();
mProcess = null;
}
} catch (IOException e) {
}
return null;
}
@Override
protected void onProgressUpdate(Void... values) {
try {
// Is a line ready to read from the "ping" command?
while (mReader.ready()) {
// This just displays the output, you should typically parse it I guess.
mText.setText(mReader.readLine());
}
} catch (IOException t) {
}
}
}
}