get process start time from proc filesystem in java.

start_time.java

int pid = Process.myPid();
String statpath = "/proc/" + pid + "/stat";
a
try {
	BufferedReader br = new BufferedReader(
			new InputStreamReader(new FileInputStream(new File(statpath)))
			);
	String[] statline = br.readLine().split(" ");
	// get system boot time
	long bootime = System.currentTimeMillis() - SystemClock.elapsedRealtime();
	
	// started_time(in milliseconds) = started_time(in jiffies) * HZ / 1000
	// HZ can be found in ndk/platforms/android-9/arch-arm/usr/include/asm/param.h
	// commonly HZ is 100
	long started = Long.parseLong(statline[21]) * 10;
	Log.d("your_tag", "started time : " + (bootime + started));
} catch (Exception e) {
	e.printStackTrace();
}