in src/main/java/org/apache/sling/servlets/get/impl/RedirectServlet.java [290:303]
private static boolean isUrl(final String path) {
for (int i = 0; i < path.length(); i++) {
char c = path.charAt(i);
if (c == ':') {
return true;
}
if (!((c >= 'a' && c <= 'z')
|| (c >= 'A' && c <= 'Z')
|| (i > 0 && ((c >= '0' && c <= '9') || c == '.' || c == '+' || c == '-')))) {
break;
}
}
return false;
}