StringTokenizer и RegEx

https://docs.oracle.com/javase/7/docs/api/java/util/StringTokenizer.html

StringTokenizer is a legacy class that is retained for compatibility reasons although its use is discouraged in new code. It is recommended that anyone seeking this functionality use the split method of String or the java.util.regex package instead.

В вашем случае более правильным будет использовать простой проход по строке (ну или можно заморочиться реализацией конечного автомата)

На скорую руку

public class Tokenizer {
    private List<String> tokens       = new ArrayList<>();
    private String       currentToken = "";
    public List<String> tokenize() {
        String      inputString = "true||false==(false||true)";
        Set<String> delimiters  = new HashSet<>(Arrays.asList("+", "-", "*", "/", "^", " ", "(", ")", "==", "&&", "||"));
        int length = inputString.length();
        for (int i = 0; i < length; i++) {
            String one = inputString.substring(i, i + 1);
            String two = i < length - 1 ? inputString.substring(i, i + 2) : "fake delimiter";
            if (delimiters.contains(one)) {
                addTokens(one);
                continue;
            }
            if (delimiters.contains(two)) {
                addTokens(two);
                i++;
                continue;
            }
            currentToken += one;
        }
        if (!currentToken.equals("")) tokens.add(currentToken);
        return tokens;
    }
    private void addTokens(String delimiter) {
        if (!currentToken.equals("")) {
            tokens.add(currentToken);
        }
        tokens.add(delimiter);
        currentToken = "";
    }
}

ideone