常用正则表达式示例

1.替换连续的重复字符串：

        String test = "www....baidu.com";
        String t = test.replaceAll("[.]+",".");

替换www….baidu.com为www.baidu.com

2.多重匹配：

    private static final Pattern BAIDU_URL_PATTERN =
            Pattern.compile("(?:http|https):\\/\\/www.baidu.com(\\/)?", Pattern.CASE_INSENSITIVE);
    BAIDU_URL_PATTERN.matcher(url).matches()

匹配http://www.baidu.com/和https://www.baidu.com/