public static String escapeJsonControlCharacters()

in log4j-core/src/main/java/org/apache/logging/log4j/core/util/Transform.java [125:187]
56 lines of code
19 McCabe index (conditional complexity)

    public static String escapeJsonControlCharacters(final String input) {
        // Check if the string is null, zero length or devoid of special characters
        // if so, return what was sent in.

        // TODO: escaped Unicode chars.

        if (Strings.isEmpty(input)
                || (input.indexOf('"') == -1
                        && input.indexOf('\\') == -1
                        && input.indexOf('/') == -1
                        && input.indexOf('\b') == -1
                        && input.indexOf('\f') == -1
                        && input.indexOf('\n') == -1
                        && input.indexOf('\r') == -1
                        && input.indexOf('\t') == -1)) {
            return input;
        }

        final StringBuilder buf = new StringBuilder(input.length() + 6);

        final int len = input.length();
        for (int i = 0; i < len; i++) {
            final char ch = input.charAt(i);
            final String escBs = "\\";
            switch (ch) {
                case '"':
                    buf.append(escBs);
                    buf.append(ch);
                    break;
                case '\\':
                    buf.append(escBs);
                    buf.append(ch);
                    break;
                case '/':
                    buf.append(escBs);
                    buf.append(ch);
                    break;
                case '\b':
                    buf.append(escBs);
                    buf.append('b');
                    break;
                case '\f':
                    buf.append(escBs);
                    buf.append('f');
                    break;
                case '\n':
                    buf.append(escBs);
                    buf.append('n');
                    break;
                case '\r':
                    buf.append(escBs);
                    buf.append('r');
                    break;
                case '\t':
                    buf.append(escBs);
                    buf.append('t');
                    break;
                default:
                    buf.append(ch);
            }
        }
        return buf.toString();
    }