Too many on loan

public void markOnLoan() throws IOException{
        System.out.println("Items not on loan:  "+(items.size()-amountOnLoan)); //on start, should return just items.size();
        try{
            Object[] possible = new Object[items.size()-amountOnLoan];//gets all possible options to mark on loan
            for(int i = 0; i < items.size();i++){
                if(items.get(i).getOnLoan() == false){
                    possible[i] = items.get(i);
                }
            }
            Object temp = JOptionPane.showInputDialog(null,"Which Item would you like to loan out?", "Loan out item", 0, null, possible, possible[0]);
            if(temp != null){
                String tempN = JOptionPane.showInputDialog(null, "Who did you loan this item too?");
            if(tempN != null){
                String tempD = JOptionPane.showInputDialog(null, "When was this item loaned out?");
                if(tempD!=null){
                    items.get(items.indexOf(temp)).markOnLoan(tempN, tempD);
                    fileWriter(items);
                    amountOnLoan = amountOnLoan + 1; //if the user hasn't pressed cancelby this point, should add 1 to the amount on loan
                    }
                }
            }
        }catch(ArrayIndexOutOfBoundsException e){
            JOptionPane.showMessageDialog(null, "No items to loan.", "Error", JOptionPane.ERROR_MESSAGE);
        }
        System.out.println("Items now on loan: " + amountOnLoan);
    }