Class Select{
  //
  //... ...  your java code
  //
  puclic static void main(String[] args){
    String id = null;
    if(args!=null&&args.length>0){
      id = args[0];
    }else{
      id = null;  //or other you wanted
    }
    //
    //... ...  your other java code
    //
  }
}