去除字符串中的空格、回车、换行符、制表符

private String replaceBlank(String str) {
        String dest = "";
        if (str!=null) {
            Pattern p = Pattern.compile("\\s*|\t|\r|\n");
            Matcher m = p.matcher(str);
            dest = m.replaceAll("");
        }
        return dest;
    }
     public static void main(String[] args) {
            System.out.println(Test.replaceBlank("  "
                    + "     just do it!"));
        }