mongodb - Create a new instance of DB from a GUI - java -

i have implement simple gui connect mongodb client using java driver.

this picture of gui:

as can see, 1 can choose database , press ok connect.
in mongodbclient class there's method (getdatabasesname) detect databases names present:

import java.util.arraylist; import java.util.iterator; import java.util.list;  import com.mongodb.mongoclient;  public class mongodbclient {      private mongoclient client;      public mongodbclient() {          try {             this.client = new mongoclient("127.0.0.1", 27017);         } catch (exception e) {             // todo auto-generated catch block             e.printstacktrace();         }                }      public mongoclient getclient() {         return client;     }      public arraylist<string> getdatabasesname(){          arraylist<string> dbsname = new arraylist<>();          list<string> dbs = this.client.getdatabasenames();         iterator<string> iterator = dbs.iterator();          while(iterator.hasnext()){             dbsname.add(iterator.next());         }         return dbsname;     }   } 

then, in main create new instance of mongodbclient , pass arraylist of databases names window1 class:

import java.util.arraylist;  public class main {      public static void main(string[] args) {         // todo auto-generated method stub          mongodbclient mongoclient = new mongodbclient();         arraylist<string> dbname = mongoclient.getdatabasesname();            try {             window1 w1 = new window1(dbname);          } catch (exception e) {              system.out.println(e.getmessage());         }          }     } 

finally, in window 1 can choose database group of buttons:

public void choosedb(arraylist<string> dbname) {          dbbutton= new jradiobutton[dbname.size()];         buttongroup group = new buttongroup();          int x = 5;          for(int = 0; i<dbname.size(); i++) {             dbbutton[i] = new jradiobutton(dbname.get(i));             dbbutton[i].setbounds(x, 28, 65, 15);             dbbutton[i].setbackground(color.white);             this.panel.add(dbbutton[i]);              x=x+100;              group.add(dbbutton[i]);         } } 

after 1 presses ok, want create new instance of db, in main class not inside window1 class.