multithreading - Printing a list array which uses threads to a text area in java -

i having problems storing , printing list array uses threads. want store list of threads in list array , print them text area can sorted user. code below array class , transaction class.

import java.util.arraylist;  /**  * @author b00533474  */ public class array {     arraylist<transaction> transactionlist = new arraylist<transaction>();      // variables     private final transaction nexttransaction;     public static int inint2 = tranacc.inint2;     public static int inint3 = tranacc.inint3;     public static string inint1 = tranacc.inint1;      //public static void main(string[] args){     public array(){     nexttransaction = new transaction(inint1, inint2, inint3, 2000);     transactionlist.add(nexttransaction);     transactionlist.get(3);      }      /*public static void main(string[] args){         array ar = new array();         ar.add(nexttransaction);     }      *       */ } 

the variables inint1 etc class called tranacc main gui of project.

package bankassig;  /**  *  * @author b00533474  */ public class transaction {     string type;     int amount;     int wknum;     int balance;      public transaction(string ty, int am, int wk, int bal)     {         type = ty;         amount = am;         wknum = wk;         balance = bal;     }   } 

my problem implementing/using list area, going add action listener button on gui call list area , print transactions in text unsure of code write ( know action listener not calling list array).

any appreciated , if need provide anymore code happy so.

how implement list array , use print out values of variables used?

overwrite inherited (from java.lang.object) tostring() method in transaction class. in tostring() method, can put string variable data in format makes sense user, , return it. can iterate through transactions in array class's list, call tostring() method, , put in gui. like:

for (transaction trans : yourarrayobj) {     yourtextarea.append(trans.tostring()); }