private void clearSetenv() {
    ProcessBuilder pb = new ProcessBuilder("/bin/bash", "shell/clear_setenv.sh");
    Map<String, String> env = pb.environment();
    if (mysql_user != null) {
      env.put("mMYSQL_USER", mysql_user);
    }
    if (mysql_pass != null) {
      env.put("mMYSQL_PASS", mysql_pass);
    }
    if (mysql_host != null) {
      env.put("mMYSQL_HOST", mysql_host);
    }
    if (mysql_port != null) {
      env.put("mMYSQL_PORT", mysql_port);
    }
    Process p = null;
    try {
      p = pb.start();
    } catch (IOException e) {
      e.printStackTrace();
    }
    if (p != null) {
      try {
        p.waitFor();
      } catch (InterruptedException e) {
        e.printStackTrace();
      }
    }
  }