1    package utils; 
2     
3     
4    public class Encoder { 
5      private static final char digits[] = { 
6        '0', '1', '2', '3', '4', '5', 
7        '6', '7', '8', '9', 'a', 'b', 
8        'c', 'd', 'e', 'f', 'g', 'h', 
9        'i', 'j', 'k', 'l', 'm', 'n', 
10       'o', 'p', 'q', 'r', 's', 't', 
11       'u', 'v', 'w', 'x', 'y', 'z', 
12       '!', '@', '#', '$', '%', '^', 
13       '&', '*', '(', ')', '`', '~', 
14       ';', ':', '<', '>', ',', '.', 
15       '/', '?', '[', ']', '{', '}', 
16       '\\', '|', '=', '_' 
17     }; 
18    
19     public static void main(String args[]) { 
20       int i = 646; 
21       //convert to base 64 numeral 
22       // can you convert the following to a for loop? 
23       int d1 = i / 64; 
24       int d1a = i % 64; 
25       int d2 = d1 / 64; 
26       int d2a = d1 % 64; 
27       int d3 = d2 / 64; 
28       int d3a = d2 % 64; 
29       int d4 = d3 / 64; 
30       int d4a = d3 % 64; 
31       int d5 = d4 / 64; 
32       int d5a = d4 % 64; 
33       int d6 = d5 / 64; 
34       int d6a = d5 % 64; 
35       int d7 = d6 / 64; 
36       int d7a = d6 % 64; 
37       int d8 = d7 / 64; 
38       int d8a = d7 % 64; 
39    
40       //digits ending in 'a' represent the remainders of the preceding digits 
41       System.out.println(i); 
42       System.out.println("converted to base 64 numeral = "); 
43       System.out.print(digits[d8a]); 
44       System.out.print(digits[d7a]); 
45       System.out.print(digits[d6a]); 
46       System.out.print(digits[d5a]); 
47       System.out.print(digits[d4a]); 
48       System.out.print(digits[d3a]); 
49       System.out.print(digits[d2a]); 
50       System.out.println(digits[d1a]); 
51     } 
52    
53     public static String toBaseR(int i, int shift) { 
54       char[] buf = new char[64]; 
55       int charPos = 64; 
56       int radix = 1 << shift; 
57       int mask = radix - 1; 
58       do { 
59         buf[--charPos] = digits[i & mask]; 
60         i >>>= shift; 
61       } while (i != 0); 
62       return new String(buf); 
63     } 
64    
65     public static void main2(String args[]) { 
66       int num = 0xffff; 
67       System.out.println(Encoder.toBaseR(num, 4)); 
68     } 
69   } 
70