public static List parseSubstring()

in repository/service/src/main/java/org/apache/karaf/cave/repository/service/bundlerepository/SimpleFilter.java [327:405]
61 lines of code
20 McCabe index (conditional complexity)

    public static List<String> parseSubstring(String value) {
        List<String> pieces = new ArrayList<>();
        int length = value.length();

        boolean isSimple = true;
        for (int idx = 0; idx < length; idx++) {
            char c = value.charAt(idx);
            if (c == '*' || c == '\\') {
                isSimple = false;
                break;
            }
        }
        if (isSimple) {
            pieces.add(value);
            return pieces;
        }

        StringBuilder ss = new StringBuilder();
        // int kind = SIMPLE; // assume until proven otherwise
        boolean wasStar = false; // indicates last piece was a star
        boolean leftstar = false; // track if the initial piece is a star
        boolean rightstar = false; // track if the final piece is a star

        int idx = 0;

        // We assume (sub)strings can contain leading and trailing blanks
        boolean escaped = false;
        for (;;) {
            if (idx >= length) {
                if (wasStar) {
                    // insert last piece as "" to handle trailing star
                    rightstar = true;
                } else {
                    pieces.add(ss.toString());
                    // accumulate the last piece
                    // note that in the case of
                    // (cn=); this might be
                    // the string "" (!=null)
                }
                ss.setLength(0);
                break;
            }

            // Read the next character and account for escapes.
            char c = value.charAt(idx++);
            if (!escaped && (c == '*')) {
                // If we have successive '*' characters, then we can
                // effectively collapse them by ignoring succeeding ones.
                if (!wasStar) {
                    if (ss.length() > 0) {
                        pieces.add(ss.toString()); // accumulate the pieces
                        // between '*' occurrences
                    }
                    ss.setLength(0);
                    // if this is a leading star, then track it
                    if (pieces.isEmpty()) {
                        leftstar = true;
                    }
                    wasStar = true;
                }
            } else if (!escaped && (c == '\\')) {
                escaped = true;
            } else {
                escaped = false;
                wasStar = false;
                ss.append(c);
            }
        }
        if (leftstar || rightstar || pieces.size() > 1) {
            // insert leading and/or trailing "" to anchor ends
            if (rightstar) {
                pieces.add("");
            }
            if (leftstar) {
                pieces.add(0, "");
            }
        }
        return pieces;
    }