java有关正则表达式的工具方法集合1

1.获取某字符串中汉字的个数

...
    private int getChineseCount(String text) {
        String Reg = "^[u4e00-u9fa5]{1}$";// 正则
        int result = 0;
        for (int i = 0; i < text.length(); i++) {
            String b = Character.toString(text.charAt(i));
            if (b.matches(Reg))
                result++;
        }
        return result;
    }
...

 2.使用正则替换某字符串中所有符合正则的字符串为指定字符串

//将str中的符合正则regu的字符串替换成replaceStr
...
    private static String replace(String str, String regu, String replaceStr) {
        Pattern pattern = Pattern.compile(regu);
        Matcher matcher = pattern.matcher(str);
        str = matcher.replaceAll(replaceStr);
        return str;
    }
...

 3.驼峰式转换成大写下划线

...
    private String humpToLine(String str) {
        Pattern humpPattern = Pattern.compile("[A-Z]");
        Matcher matcher = humpPattern.matcher(str);
        StringBuffer sb = new StringBuffer();
        while (matcher.find()) {
            matcher.appendReplacement(sb, "_" + matcher.group(0).toLowerCase());
        }
        matcher.appendTail(sb);
        return sb.toString().toUpperCase();
    }
...

 4.大写下划线转换成驼峰式

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    private String lineToHump(String str) {
        Pattern linePattern = Pattern.compile("_(\w)");
        str = str.toLowerCase();
        Matcher matcher = linePattern.matcher(str);
        StringBuffer sb = new StringBuffer();
        while (matcher.find()) {
            matcher.appendReplacement(sb, matcher.group(1).toUpperCase());
        }
        matcher.appendTail(sb);
        return sb.toString();
    }
...