mapintent.java

    public void GoToGMaps(View view){
        Intent intent = null;
        String ubicacionlng = "37.7749";
        String ubicacionlat = "-122.4194";
        try {
            // Revisa si GMaps app está instalada, luego muestra la coordenada "37.7749,-122.4194"
            this.getPackageManager().getPackageInfo("com.google.android.apps.maps", 0);
            intent = new Intent(Intent.ACTION_VIEW, Uri.parse("google.navigation:q=" + ubicacionlat + "," + ubicacionlng));
            intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        } catch (Exception e) {
            // Si no está instalada, usa browser
            intent = new Intent(Intent.ACTION_VIEW, Uri.parse("https://maps.google.com/maps?z=12&t=m&q=loc:" + ubicacionlat + "+" + ubicacionlng));
        }
        this.startActivity(intent);
    }