将10进制转化为62进制

private String _10_to_62(long number) {

Long rest = number;

Stack stack =new Stack();

StringBuilder result =new StringBuilder(0);

while (rest !=0) {

stack.add(SHORT_URL_CHARS[new Long((rest - (rest /62) *62)).intValue()]);

rest = rest /62;

}

for (; !stack.isEmpty(); ) {

result.append(stack.pop());

}

return result.toString();

}