This example demonstrates an action that selects the word adjacent to the caret. If the caret is adjacent to two words, the word following the caret is selected. The implementation uses BreakIterator.getWordInstance() to find word boundaries. 
    public TextAction selectWordAction = new TextAction("Select Word") {
        public void actionPerformed(ActionEvent evt) {
            JTextComponent c = getTextComponent(evt);
            if (c == null) {
                return;
            }
            int pos = c.getCaretPosition();
    
            try {
                // Find start of word from caret
                int start = Utilities.getWordStart(c, pos);
    
                // Check if start precedes whitespace
                if (start < c.getDocument().getLength()
                    && Character.isWhitespace(c.getDocument().getText(start, 1).charAt(0))) {
                    // Check if caret is at end of word
                    if (pos > 0
                        && !Character.isWhitespace(c.getDocument().getText(pos-1, 1).charAt(0))) {
                        // Start searching before the caret
                        start = Utilities.getWordStart(c, pos-1);
                    } else {
                        // Caret is not adjacent to a word
                        start = -1;
                    }
                }
                if (start != -1) {
                    // A non-whitespace character follows start.
                    // Find end of word from start.
                    int end = Utilities.getWordEnd(c, start);
    
                    // Set selection
                    c.setSelectionStart(start);
                    c.setSelectionEnd(end);
                }
            } catch (BadLocationException e) {
            }
        }
    };
    
    public TextAction selectNextWordAction = new TextAction("Select Next Word") {
        public void actionPerformed(ActionEvent evt) {
            JTextComponent c = getTextComponent(evt);
            if (c == null) {
                return;
            }
            int pos = c.getSelectionStart();
            int len = c.getDocument().getLength();
    
            try {
                // Find start of next word from selection.
                // getNextWord() throws BadLocationException if no word follows pos.
                int start = Utilities.getNextWord(c, pos);
    
                // Find end of word from start
                int end = Utilities.getWordEnd(c, start);
    
                // Set selection
                c.setSelectionStart(start);
                c.setSelectionEnd(end);
            } catch (BadLocationException e) {
            }
        }
    };
    
    public TextAction selectPrevWordAction = new TextAction("Select Previous Word") {
        public void actionPerformed(ActionEvent evt) {
            JTextComponent c = getTextComponent(evt);
            if (c == null) {
                return;
            }
            int pos = c.getSelectionStart();
            int len = c.getDocument().getLength();
    
            try {
                // Find start of previous word from selection.
                // getPreviousWord() throws BadLocationException if no word precedes pos.
                int start = Utilities.getPreviousWord(c, pos);
    
                // Find end of word from start
                int end = Utilities.getWordEnd(c, start);
    
                // Set selection
                c.setSelectionStart(start);
                c.setSelectionEnd(end);
            } catch (BadLocationException e) {
            }
        }
    };

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