Java - useful functions

// exit
this.dispose();

// dialog
JOptionPane.showMessageDialog(null, "Hello World");

// focusing on the bar
textField.transferFocus();

// max / min
int max = Collections.max(Arrays.asList(java, data, cprog, comp));
int min = Collections.min(Arrays.asList(java, data, cprog, comp));

// textfield / button turn-off
textfield.setEnabled(false);
textfield.setText("");
button.setEnabled(false);