JTextField 를 상속받은 IPTextField Component 구현

public class IPTextField extends JTextField{

//0.0.0.0 ~ 255.255.255.255

int min = 7;

public IpTextField(String t){

super(15);

setText(t);

initListeners();

}

public void initListeners(){

addKeyListener(new KeyListener() {

public void keyTyped(KeyEvent e) {}

public void keyReleased(KeyEvent e) {

int column = getColumns();

int length = getText().length();

if(length>column){

setText(getText().substring(0,column));

JOptionPane.showMessageDialog(IPTextField.this, "IP Format Error :"+column);

return;

}

}

public void keyPressed(KeyEvent e) {}

});

addFocusListener(new FocusListener() {

public void focusLost(FocusEvent e) {

int length = getText().length();

if(min> length) {

JOptionPane.showMessageDialog(IPTextField.this, "Column Minimum Size:"+min);

return;

}

try{

InetAddress.getAllByName(getText());

}catch(Exception e1){

JOptionPane.showMessageDialog(IPTextField.this, e1);

return;

}

}

public void focusGained(FocusEvent e) {}

});

}

}