java - ArrayList repeats the same data from a database? -

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• duplicate objects added list [duplicate] 4 answers

i have jtable uses arraylist load data database, have issue same data keeps repeating themselves. missing here ? in advance,

    private void allticketrecords() {     try {         ticketrecorddao ticketrecdao = new ticketrecorddao();          arraylist<ticketrecord> records = ticketrecdao.getallticketsrecords();           object[] tablecolumnname = new object[7];          tablecolumnname[0] = "date";         tablecolumnname[1] = "h.license";         tablecolumnname[2] = "first name";         tablecolumnname[3] = "last name";         tablecolumnname[4] = "ticket id";         tablecolumnname[5] = "violation";         tablecolumnname[6] = "cost";          defaulttablemodel tbd = new defaulttablemodel();          tbd.setcolumnidentifiers(tablecolumnname);          this.ticketssummarytable.setmodel(tbd);          object[] rowrec = new object[7];          (int = 0; < records.size(); i++) {              rowrec[0] = records.get(i).getdate();             rowrec[1] = records.get(i).getemp_id();             rowrec[2] = records.get(i).getfname().touppercase();             rowrec[3] = records.get(i).getlname().touppercase();             rowrec[4] = records.get(i).getticket_id();             rowrec[5] = records.get(i).getviolation();             rowrec[6] = nf.format(records.get(i).getcost());              tbd.addrow(rowrec);          }     } catch (sqlexception e) {         system.out.println(e.tostring());     }  }   public arraylist<ticketrecord> getallticketsrecords() throws sqlexception {      string sql = "select date, t.emp_id ,e.fname, e.lname ,ticket_id, violation, cost"             + " employee e inner join ticket t on e.emp_id = e.emp_id"             + " order date";     dbconnection con = new dbconnection();     connection connect = con.getconnection();     statement stm = null;     arraylist<ticketrecord> records = new arraylist<>();      try {         stm = connect.createstatement();         resultset rs = stm.executequery(sql);          while (rs.next()) {              ticketrecord tickterec = new ticketrecord();              tickterec.setdate(rs.getstring("date"));             tickterec.setemp_id(rs.getint("emp_id"));             tickterec.setfname(rs.getstring("fname"));             tickterec.setlname(rs.getstring("lname"));             tickterec.setticket_id(rs.getstring("ticket_id"));             tickterec.setviolation(rs.getstring("violation"));             tickterec.setcost(rs.getdouble("cost"));              records.add(tickterec);          }      } catch (sqlexception e) {         system.out.println("" + e.tostring());      } {         if (connect != null) {             connect.close();         }         if (stm != null) {             stm.close();         }     }     return records;  } 

the main cause of problem seems related to...

object[] rowrec = new object[7]; (int = 0; < records.size(); i++) {      rowrec[0] = records.get(i).getdate(); 

basically, you're using same instance of rowrec, changing elements of array, effect of other added rows.

instead, create new instance of rowrec each row...

for (int = 0; < records.size(); i++) {     object[] rowrec = new object[7];     rowrec[0] = records.get(i).getdate(); 

i'd verify database results make sure there aren't duplicates sure ;)

on side node, create custom tablemodel, extending abstracttablemodel, use ticketrecord directly, rather decomposing existing record values defaulttablemodel, that's me