alert in java code example

Example 1: java swing alert window

JOptionPane.showMessageDialog(yourFrame,
    "WARNING.",
    "Warning",
    JOptionPane.WARNING_MESSAGE);

Example 2: java display message

alert('Message');

Example 3: java alert box

1- import static javax.swing.JOptionPane.showMessageDialog;
2- showMessageDialog(null, "My Result est " + ResultVariable);