How can I set a default file for JFileChooser

Question

Hi. I am developing a p2p chat application and I have to unrelated questions.
1. How can I set a default file name for JFileChooser, to save a completly new file?
2. I have a JTextArea that I append recieved messages. But when a message is appended, the whole desktop screen refreshes. How can I prevent that?
Hope I was clear. Thanks in advance.

Answer 1

Thank you for the first answer, it solved my problem. Here is the code for 2nd question, I've trimmed it a lot, hope I didn't cut off any critical code
public class ConversationWindow extends JFrame implements KeyListener,MessageArrivedListener,ActionListener,IOnlineUsrComp{
     private TextArea incomingArea;
     private Conversation conversation;
     private JTextField outgoingField;
     private JScrollPane incomingTextScroller;
     private String userName;
     private JButton inviteButton;
     private JButton sendFileButton;
     private JFileChooser fileChooser;
     private FontMetrics fontMetrics;
     private HashMap<String, String> onlineUserMap;
     public void MessageArrived(MessageArrivedEvent e) {
          showMessage(e.getArrivedMessage());
     public ConversationWindow(Conversation conversation)
          this.conversation=conversation;
          userName=User.getInstance().getUserName();
          sendFileButton=new JButton("Dosya G�nder");
          sendFileButton.addActionListener(this);
          inviteButton=new JButton("Davet et");
          inviteButton.addActionListener(this);
          incomingArea=new TextArea();
          incomingArea.setEditable(false);
          incomingArea.setFont(new Font("Verdana",Font.PLAIN,12));
          fontMetrics =incomingArea.getFontMetrics(incomingArea.getFont());
          incomingArea.setPreferredSize(new Dimension(300,300));
          outgoingField=new JTextField();
          outgoingField.addKeyListener(this);
          incomingTextScroller=new JScrollPane(incomingArea);          
          JPanel panel=new JPanel();
          panel.setLayout(new BoxLayout(panel,BoxLayout.PAGE_AXIS));
          panel.add(inviteButton);
          panel.add(sendFileButton);
          panel.add(incomingTextScroller);
          panel.add(outgoingField);
          add(panel);
          pack();
          setTitle("Ki&#351;iler:");
          setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
          setLocationRelativeTo(null);
          addWindowListener(new CloseAdapter());
     //Sends the message to other end
     public void keyPressed(KeyEvent e) {
          if(e.getKeyCode()==KeyEvent.VK_ENTER && e.getSource()==outgoingField)
               String message=outgoingField.getText();
               if(message.equals("")) return;
               showMessage(userName+": "+message);
               conversation.sendMessages(userName+": "+message);
               outgoingField.setText("");     
     //Displays the recieved message
     public void showMessage(String message)
          if(fontMetrics.stringWidth(message)>incomingArea.getWidth())
               int mid=message.length()/2;
               StringBuilder sbld=new StringBuilder(message);
               for(;mid<message.length();mid++)
                    if(message.charAt(mid)==' ')
                         sbld.setCharAt(mid, '\n');
                         message=sbld.toString();
                         break;
          incomingArea.append("\n"+message);
}