1 public static void main(String args[]){
 2         String regPattern = "[\u4e00-\u9fa5a-zA-Z_][\\s_\u4e00-\u9fa5a-zA-Z0-9]{0,}[\u4e00-\u9fa5a-zA-Z0-9_]\\s{0,4}";
 3         String str = "a_a今天aaabbbbbbbaaaaassss              今天    ";
 4         System.out.println(validStr(str,regPattern));
 5     }
 6     /**
 7      * 校验字符串
 8      * @param str 待校验的字符串
 9      * @param regPattern  正则表达式
10      * @return
11      */
12     public static boolean validStr(String str,String regPattern){
13         Pattern pattern = Pattern.compile(regPattern);
14         Matcher matcher = pattern.matcher(str);
15         return matcher.matches();
16     }