How to find out the running/start time of android application?

Is there anyway to find out the start time of an application?ActivityManager provides pids etc for开发者_运维知识库 each application process but doesn't tell for how long process is running.

This will return process start time (since system boot):

private static long getStartTime(final int pid) throws IOException {
    final String path = "/proc/" + pid + "/stat";
    final BufferedReader reader = new BufferedReader(new FileReader(path));
    final String stat;
    try {
        stat = reader.readLine();
    } finally {
        reader.close();
    }
    final String field2End = ") ";
    final String fieldSep = " ";
    final int fieldStartTime = 20;
    final int msInSec = 1000;
    try {
        final String[] fields = stat.substring(stat.lastIndexOf(field2End)).split(fieldSep);
        final long t = Long.parseLong(fields[fieldStartTime]);
        final int tckName = Class.forName("libcore.io.OsConstants").getField("_SC_CLK_TCK").getInt(null);
        final Object os = Class.forName("libcore.io.Libcore").getField("os").get(null);
        final long tck = (Long)os.getClass().getMethod("sysconf", Integer.TYPE).invoke(os, tckName);
        return t * msInSec / tck;
    } catch (final NumberFormatException e) {
        throw new IOException(e);
    } catch (final IndexOutOfBoundsException e) {
        throw new IOException(e);
    } catch (ReflectiveOperationException e) {
        throw new IOException(e);
    }
}

To get process running time:

final long dt = SystemClock.elapsedRealtime() - getStartTime(Process.myPid());

I don't know wether there's an API for this. But one approach would be to use something like:

String pid = "yourpid";    
BufferedReader reader = new BufferedReader ( new InputStreamReader ( new FileInputStream ( "ls -ld /proc/"+pid)) , 1000 );

To get the start time of your application and the just subtract that with the currenttime.

Might not be the best way, but that's what came to mind. (And I haven't tried it..)

Gl !