Get topTask and it's PID

gistfile1.java

static final String TAG = "XXX_TAG"
am = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);
RunningTaskInfo topTask = am.getRunningTasks(1).get(0);
String pkg = topTask.baseActivity.getPackageName();
int pid = findForgroundPID(pkg);

private int findForgroundPID(String topPackage) {
	int pid = -1;
	List<RunningAppProcessInfo> procList = am.getRunningAppProcesses();
	for (RunningAppProcessInfo proc : procList) {
		if (proc.importance == RunningAppProcessInfo.IMPORTANCE_FOREGROUND) {
			for (String pkg : proc.pkgList) {
				if (pkg.equals(topPackage)) {
					pid = proc.pid;
					Log.v(TAG, "[last app]" + topPackage + " [PID]" + pid );
				}
			}
		}
	}
	return pid;
}