Java judging numbers or Chinese or letters

1. Determine if the string is only a numeric:1> with Java-brought function public static boolean isnumeric (string str) {  for   (Int i = str.length ();--i>=0;) {      if  (! Character.isdigit (Str.charat (i))) {    return false;   }  }   return true; }2> Regular Expression public static boolean isnumeric (STRING&NBSP;STR) {    pattern pattern = pattern.compile ("[0-9]*");     Return pattern.matcher (str). Matches ();    }3> with ASCII code public static  Boolean isnumeric (STRING&NBSP;STR) {   for (Int i=str.length ();--i>=0;) {       int chr=str.charat (i);       if (chr<48 | |  chr>57)          return false;   }    return true;} &Nbsp; 2. Determines whether the first character of a string is a letter public   static   boolean   test ( String   s)      {     char   c    =   s.charat (0);     int   i    = (int) c;     if ((i>=65&&i<=90) | | (i>=97&&i<=122))      {     return   true;      }     else     {      Return   false;     }     }  public      static   boolean   check (String    Fstrdata)              {       &nbsP;              char   c    =   fstrdata.charat (0);                      if (((c>= ' a ' &&c<= ' Z ')    | |     (c>= ' A ' &&c<= ' Z '))                     {                             return   true;                    }else{                            return & nbsp; false;                      }             } &NBSP;&NBSP;3&NBSP: Judging Whether it is a Chinese character public boolean vd (STRING&NBSP;STR) {        char[] chars=str.tochararray ();     boolean isgb2312=false;      for (int i=0;i<chars.length;i++) {                 byte[] bytes= ("" +chars[i]). GetBytes ();                  if (bytes.length==2) {                               int[] ints=new int[2];                               ints[0]=bytes[0]& 0xff;                               ints[1]=bytes[1]& 0xff;                                 if (Ints[0]>=0x81 && ints[0]<=0xfe &&  ints[1] &GT;=0X40&NBSP;&AMP;&AMP;&NBSP;INTS[1]&LT;=0XFE) {                                           isGB2312=true;                                           break;                               }                  }     }      return isgb2312; }

Java judging numbers or Chinese or letters