[Java] JSON escape special character

Ref: 剑飘江湖的博客 – JSON格式数据中特殊字符的处理

   public static String stringToJson(String s) {
    if (StringUtils.isEmpty(s)) {
        return s;
    }
    StringBuffer sb = new StringBuffer ();
    for (int i=0; i<s.length(); i++) {

        char c = s.charAt(i);
        switch (c) {
            case '"':
                sb.append("\"");
                break;
            /*case '\':   
                sb.append("\\");
                break;
            case '/':
                sb.append("\/");
                break;*/
            case 'b':      
                sb.append("\b");
                break;
            case 'f':      
                sb.append("\f");
                break;
            case 'n':
                sb.append("\n"); 
                break;
            case 'r':      
                sb.append("\r");
                break;
            case 't':      
                sb.append("\t");
                break;
            default:
                sb.append(c);
        }
    }
    return sb.toString();
}