Counting Uppercase, LowerCase, Digits in a File Java Example

import java.io.*; 
 class CountingUppercaseJavaExample 
 { 
          public static void main(String args[]) throws IOException 
         { 
                String t;  
                int up,lo,nu,sp,n,i,m;  
                BufferedReader fin = new BufferedReader(new FileReader(args[0])); 
                up=lo=nu=sp=0; 
                while(true) 
                       { 
                         try 
                             { 
                                  t=fin.readLine(); 
                                  if (t==null) break; 
                                  n = t.length(); 
                                  for (i=0;i<=n-1;i++) 
                                       { 
                                          m= t.charAt(i); 
                                          if(m>=97 && m<=122) 
                                                { 
                                                   lo++; 
                                                 } 
                                                   else 
                                                        { 
                                                             if(m>=65 && m<=90) 
                                                                { 
                                                                    up++; 
                                                                 } 
                                                                       else 
                                                                             { 
                                                                                  if(m>=48 && m<=57) 
                                                                                      { 
                                                                                          nu++; 
                                                                                      } 
                                                                                          else 
                                                                                             { 
                                                                                                 sp++; 
                                                                                              } 
                                                                              } 
                                                        } 
                                          } 
                              } 
                            catch(IOException e){} 
                      } 
                       System.out.println("the number of lower case characters are"+lo); 
                       System.out.println("the number of upper case characters are"+up); 
                       System.out.println("the number of numerical digits are"+nu); 
                       System.out.println("the number of other characters are"+sp); 
          } 
  }