KEYTYPED

KeyTyped is an event type in the Java AWT and Swing event model. It represents the typing of a character by the user and is delivered after a key has been pressed and released to produce a character. It is a higher-level event than keyPressed and keyReleased and is intended for text input.

In a KeyEvent, the keyCode is meaningful for KEY_PRESSED and KEY_RELEASED, but for KEY_TYPED the keyCode is VK_UNDEFINED. The actionable data in a KEY_TYPED event comes from getKeyChar(), which returns the Unicode character produced by the input. The returned character reflects modifiers such as Shift, and may include diacritics or compose characters when using input methods.

KEY_TYPED events are commonly used with text components and for simple input handling, such as filtering or validating characters as they are typed. Listeners implement KeyListener and override keyTyped(KeyEvent e), or extend KeyAdapter. Within the handler, developers typically retrieve the character with e.getKeyChar() and decide whether to accept it or perform some action.

Notes and limitations: KEY_TYPED events are not generated for non-printing keys like arrow keys or Escape, and their behavior can be influenced by platform differences and input methods (IME). For robust text handling in Swing, higher-level approaches such as DocumentListener, input verifiers, or document filters are often preferred over low-level key events, since they respond to edits in the document rather than individual keystrokes.