protected static String unescapeJava()

in core/src/main/java/org/apache/struts2/util/PropertiesReader.java [342:418]
64 lines of code
19 McCabe index (conditional complexity)

    protected static String unescapeJava(String str, char delimiter) {
        if (str == null) {
            return null;
        }
        int sz = str.length();
        StringBuilder out = new StringBuilder(sz);
        StringBuilder unicode = new StringBuilder(UNICODE_LEN);
        boolean hadSlash = false;
        boolean inUnicode = false;
        for (int i = 0; i < sz; i++) {
            char ch = str.charAt(i);
            if (inUnicode) {
                // if in unicode, then we're reading unicode
                // values in somehow
                unicode.append(ch);
                if (unicode.length() == UNICODE_LEN) {
                    // unicode now contains the four hex digits
                    // which represents our unicode character
                    try {
                        int value = Integer.parseInt(unicode.toString(), HEX_RADIX);
                        out.append((char) value);
                        unicode.setLength(0);
                        inUnicode = false;
                        hadSlash = false;
                    } catch (NumberFormatException nfe) {
                        throw new RuntimeException("Unable to parse unicode value: " + unicode, nfe);
                    }
                }
                continue;
            }

            if (hadSlash) {
                // handle an escaped value
                hadSlash = false;

                if (ch == '\\') {
                    out.append('\\');
                } else if (ch == '\'') {
                    out.append('\'');
                } else if (ch == '\"') {
                    out.append('"');
                } else if (ch == 'r') {
                    out.append('\r');
                } else if (ch == 'f') {
                    out.append('\f');
                } else if (ch == 't') {
                    out.append('\t');
                } else if (ch == 'n') {
                    out.append('\n');
                } else if (ch == 'b') {
                    out.append('\b');
                } else if (ch == delimiter) {
                    out.append('\\');
                    out.append(delimiter);
                } else if (ch == 'u') {
                    // uh-oh, we're in unicode country....
                    inUnicode = true;
                } else {
                    out.append(ch);
                }

                continue;
            } else if (ch == '\\') {
                hadSlash = true;
                continue;
            }
            out.append(ch);
        }

        if (hadSlash) {
            // then we're in the weird case of a \ at the end of the
            // string, let's output it anyway.
            out.append('\\');
        }

        return out.toString();
    }