java_64進位和10進位的轉換類

package com.test;/** * 64進位和10進位的轉換類 *  * @author Administrator *  */public class Encode64 {final static char[] digits = { '0', '1', '2', '3', '4', '5', '6', '7', '8','z', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L','9', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l','m', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y','M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y','Z', '+', '/', };/** * @param args * @throws InterruptedException */public static void main(String[] args) throws InterruptedException {long timeMillins = System.currentTimeMillis();System.out.println("初始值:" + timeMillins);String tmp = CompressNumber(timeMillins);System.out.println("加密後:" + tmp);System.out.println("解密後:" + UnCompressNumber(tmp));}/** * 把10進位的數字轉換成64進位 *  * @param number * @param shift * @return */private static String CompressNumber(long number) {char[] buf = new char[64];int charPos = 64;int radix = 1 << 6;long mask = radix - 1;do {buf[--charPos] = digits[(int) (number & mask)];number >>>= 6;} while (number != 0);return new String(buf, charPos, (64 - charPos));}/** * 把64進位的字串轉換成10進位 *  * @param decompStr * @return */private static long UnCompressNumber(String decompStr) {long result = 0;for (int i = decompStr.length() - 1; i >= 0; i--) {for (int j = 0; j < digits.length; j++) {if (decompStr.charAt(i) == digits[j]) {result += ((long) j) << 6 * (decompStr.length() - 1 - i);}}}return result;}}

具體實現如下