code: public static String quote(String str) {
          int len = str.length();
          StringBuffer buf = new StringBuffer(len+2);
          buf.append("\"");
          char c;
          for (int i=0;i<len;i++) {
              c = str.charAt(i);
              if (c == '"' || c == '\\') {
                  buf.append("\\");
              }
              buf.append(c);
          }
          buf.append("\"");
          return buf.toString();
      }
docs: Quotifies a specified string.
  The entire string is encompassed by double quotes and each
  " is replaced with \", \ is replaced with \\.
  
  @param str the string to quotify
  @return quotified and escaped string