Java by API/javax.swing.text/Keymap

Keymap: addActionForKeyStroke(KeyStroke key, Action a)

import javax.swing.*;
import javax.swing.text.*;
import java.util.Hashtable;
import java.awt.event.*;
import java.awt.BorderLayout;
public class KeymapExample {
  public static void main(String[] args) {
    JTextArea area = new JTextArea(6, 32);
    Keymap parent = area.getKeymap();
    Keymap newmap = JTextComponent.addKeymap("KeymapExampleMap", parent);
    KeyStroke u = KeyStroke.getKeyStroke(KeyEvent.VK_U, InputEvent.CTRL_MASK);
    Action actionU = new UpWord(); 
    newmap.addActionForKeyStroke(u, actionU);
    Action actionList[] = area.getActions();
    Hashtable lookup = new Hashtable();
    for (int j=0; j < actionList.length; j+=1)
      lookup.put(actionList[j].getValue(Action.NAME), actionList[j]);
    KeyStroke L = KeyStroke.getKeyStroke(KeyEvent.VK_L, InputEvent.CTRL_MASK);
    Action actionL = (Action)lookup.get(DefaultEditorKit.selectLineAction);
    newmap.addActionForKeyStroke(L, actionL);
    KeyStroke W = KeyStroke.getKeyStroke(KeyEvent.VK_W, InputEvent.CTRL_MASK);
    Action actionW = (Action)lookup.get(DefaultEditorKit.selectWordAction);
    newmap.addActionForKeyStroke(W, actionW);
    area.setKeymap(newmap);
    JFrame f = new JFrame("KeymapExample");
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    f.getContentPane().add(new JScrollPane(area), BorderLayout.CENTER);
    area.setText("www.\n jexp \n .ru.");
    f.pack();
    f.setVisible(true);
  }
  public static class UpWord extends TextAction {
    public UpWord() {
      super("uppercase-word-action");
    }
    public void actionPerformed(ActionEvent e) {
      JTextComponent comp = getTextComponent(e);
      if (comp == null) return;
      Document doc = comp.getDocument();
      int start = comp.getSelectionStart();
      int end = comp.getSelectionEnd();
      try {
        int left = javax.swing.text.Utilities.getWordStart(comp, start);
        int right = javax.swing.text.Utilities.getWordEnd(comp, end);
        String word = doc.getText(left, right-left);
        doc.remove(left, right-left);
        doc.insertString(left, word.toUpperCase(), null);
        comp.setSelectionStart(start); // restore previous position/selection
        comp.setSelectionEnd(end);
      } catch (BadLocationException ble) { return; }
    }
  }
}

Keymap: removeKeyStrokeBinding(KeyStroke keystroke)

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.KeyStroke;
import javax.swing.text.Keymap;
public class MainClass {
  public static void main(final String args[]) {
    JFrame frame = new JFrame("Default Example");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    JTextField textField = new JTextField();
    frame.add(textField, BorderLayout.NORTH);
    JPanel panel = new JPanel();
    JButton defaultButton = new JButton("Default Button");
    defaultButton.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent actionEvent) {
        System.out.println(actionEvent.getActionCommand() + " selected");
      }
    });
    panel.add(defaultButton);
    JButton otherButton = new JButton("Other Button");
    otherButton.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent actionEvent) {
        System.out.println(actionEvent.getActionCommand() + " selected");
      }
    });
    panel.add(otherButton);
    frame.add(panel, BorderLayout.SOUTH);
    Keymap keymap = textField.getKeymap();
    KeyStroke keystroke = KeyStroke.getKeyStroke(KeyEvent.VK_ENTER, 0, false);
    keymap.removeKeyStrokeBinding(keystroke);
    frame.getRootPane().setDefaultButton(defaultButton);
    frame.setSize(250, 150);
    frame.setVisible(true);
  }
}