Java Library to validate and compare MAC address

Question

We have a Java web service that gets a String representing a MAC address. We want to validate if the given String actually matches the required format. Further we want to create a normalized form to make them comparable.

I searched quite a while but found only some "loose regular expressions". We would really prefer to have a library that can parse different formats and return a normalized (String) representation (i.e. 01-23-45-67-89-ab and 01:23:45:67:89:ab would return the same representation and be comparable).

I expected to find some mature and well tested library, which could do that kind of task. Can anyone please point me to it? I just cannot believe that it doesn't exist yet.

I would be very thankful to not see any RegExes as possible solutions (we know how to do that if necessary).

Answer 1

The IPAddress Java library will do it. The javadoc is available at the link. Disclaimer: I am the project manager.

The library will read various common formats for MAC addresses, like aa:bb:cc:dd:ee:ff, aa-bb-cc-dd-ee-ff, aabb.ccdd.eeff, it supports addresses that are 48 or 64 bits, and also allows you to specify ranges of addresses like aa-ff:bb:cc:*:ee:ff

Verify if an address is valid:

    String str = "aa:bb:cc:dd:ee:ff";
    MACAddressString addrString = new MACAddressString(str);
    try {
         MACAddress addr = addrString.toAddress();
         ...
    } catch(AddressStringException e) {
        //e.getMessage provides validation issue
    }

The library is well tested, it has a test suite with thousands of tests.

Answer 2

mature and well tested library

To verify MAC addresses? It's 6 bytes in hex optionally separated by a delimiter. It's a homework assignment or light interview question, no need to write a library. My solution is 10 lines, and it's more paranoid than necessary...