public static void main(String[] args) {
        String testStr = "{\"A0\":\"2011-10-11 12:08:06:This is the first message\",\"A1\":\"2011-10-11 12:08:06:This is the second message\"}";
        String reg = "\"A[\\d]+\":\"([\\d]{4}-[\\d]{2}-[\\d]{2} [\\d]{2}:[\\d]{2}:[\\d]{2}):([^\"]+)\"";
        Pattern p = Pattern.compile(reg);
        Matcher matcher = p.matcher(testStr);
        while (matcher.find()) {
            System.out.println(matcher.group(1) + "   " + matcher.group(2));
        }
    }