Is it possible from one string (date) generate another fixed length string (5-char code) by some encrypting algorithm for example? Also should be possible to confirm that a output string (5-char code) has been generated using the input string (date)
What I need:
Slightly hacky and not tested fully, but seems to do the job. I shall leave you to code the inverse function for validation:
public static String generateCode(String s) {
String result = null;
s = s.replaceAll("\\D", "");
result = new BigInteger(s).toString(36).toUpperCase();
while (result.length() < 5) {
result = "0" + result;
}
return result;
}
class HelloWorld {
public static void main(String[] args) {
System.out.println(toHexString("10-10-2010".getBytes()));
System.out.println();
System.out.println(fromHexString("31302d31302d32303130"));
}
public static String toHexString(byte[] ba) {
StringBuilder str = new StringBuilder();
for(int i = 0; i < ba.length; i++)
str.append(String.format("%x", ba[i]));
return str.toString();
}
public static String fromHexString(String hex) {
StringBuilder str = new StringBuilder();
for (int i = 0; i < hex.length(); i+=2) {
str.append((char) Integer.parseInt(hex.substring(i, i + 2), 16));
}
return str.toString();
}
}