Split the string into sets of two characters at a time.
Integer parse at base 16 the split parts.
Convert to char.
package mypackage;
public class Program {
public static void main(String[] args) {
final String input = "323830303030346434313461343135383538346435323462343134343535333833303339333033363030303164346330303130313031313630343031303130353165303030653038316130643164303435323236";
final StringBuilder builder = new StringBuilder();
for(int i = 0; i < (input.length() - 1); i += 2) {
final String part = input.substring(i, i + 2);
final int intValue = Integer.parseInt(part, 16);
final char character = (char)intValue;
builder.append(character);
}
System.out.println(builder.toString());
}
}
Hope this helps,
Fredrik