Escape routines for java text

JavaEscapeUtil.java

class JavaEscapeUtil {

    /**
     * Replaces unprintable characters by their escaped (or unicode escaped)
     * equivalents in the given string
     */
    public static String escapeJava(String str) {
        StringBuilder retval = new StringBuilder();
        for (int i = 0; i < str.length(); i++) {
            final char ch = str.charAt(i);
            switch (ch) {
            case 0:
                retval.append("\\0");
                break;
            case '\b':
                retval.append("\\b");
                break;
            case '\t':
                retval.append("\\t");
                break;
            case '\n':
                retval.append("\\n");
                break;
            case '\f':
                retval.append("\\f");
                break;
            case '\r':
                retval.append("\\r");
                break;
            case '\"':
                retval.append("\\\"");
                break;
            case '\'':
                retval.append("\\'");
                break;
            case '\\':
                retval.append("\\\\");
                break;
            default:
                if (ch < 0x20 || ch > 0x7e) {
                    String s = "0000" + Integer.toString(ch, 16);
                    retval.append("\\u").append(s.substring(s.length() - 4));
                } else {
                    retval.append(ch);
                }
                break;
            }
        }
        return retval.toString();
    }

}

See https://gist.github.com/uklimaschewski/6741769 for the reverse conversion (escaped -> unescaped)

Hey thank you so much, is it okay if I use this in a uni project/assignment?
I will include references to the original. If not, all good :).

Also I may be reading the code incorrectly, but at https://gist.github.com/oowekyala/741cab7e54b8040d1f0356a66e327552#file-javaescapeutil-java-L12 wouldn't you use \\0?

Sure, go ahead.

Yeah you're right it should output \0

Thanks.