提取正则表达式匹配的内容

    /** 数值匹配正则表达式 */
    private static final Pattern NUM_PATTERN = Pattern.compile("[0-9]");
    /**
     * 解析字符串中数值
     * @param text 含有数值的字符串，例如,库存剩余200件
     * @return 数值
     */
    public static Integer parseString(String text) {
        Matcher matcher = NUM_PATTERN.matcher(text);
        StringBuilder sb = new StringBuilder();
        while (matcher.find()) {
            System.out.println(matcher.group());
            sb.append(matcher.group());
        }
        String str = String.valueOf(sb.toString());
        return str.isEmpty() ? null : Integer.parseInt(str);
    }