// ---- compare both arrays
boolean isEqual = true;
for (Object of : af.toList()) {
boolean oneIsEquals = false;
for (Object ol : al.toList()) {
// ---- according to PDF Reference 1-4, ID is an array containing two
// strings
if (!oneIsEquals)
oneIsEquals = ((COSString) ol).getString().equals(((COSString) of).getString());
}