CODEWITHSUNDEEP
javaandroiduuidillegalargumentexception
kramer65
kramer65

Reputation: 53873

UUID.fromString() returns an invalid UUID?

In my Android app I've got this method which takes a UUID. Unfortunately when I do this:

OverviewEvent overviewevent = eventAdapter.getOverviewEvent(UUID.fromString("0f14d0ab-9605-4a62-a9e4-5ed26688389b"));

I get an error saying java.lang.IllegalArgumentException: Invalid UUID: 100

The implementation of the getOverviewEvent is as follows:

public OverviewEvent getOverviewEvent(UUID uuid) throws Exception {
    // Do stuff
}

Does anybody know how I can solve this?

Upvotes: 13

Views: 66247

Answers (3)

Recycled Steel
Recycled Steel

Reputation: 2272

Did you copy and paste the code, I have found that a few characters that look correct are in fact the wrong ACSII code.

Remove the - and replace them again.

I have had this often with " as different editors/computers may use a slightly different code.

Upvotes: 1

Cosmo
Cosmo

Reputation: 930

I had this problem too. I think this is because my Java version is low. I found that in my Android application, uuid.split("-") and uuid.replace("-") are both useless. I guess it may be caused by that Java regards "-" as a regular expression. However when I try uuid.split("\\-") and uuid.replace("\\-"), they didn't work either. I don't know why this happened. I think it's a bug of Java.

According to Fildor's comment, in Android's implementation, uuid.split("-") is used to split the uuid string into 5 parts. Then because of the mentioned bug, the uuid string couldn't be spliced into 5 parts. So "Invalid UUID" exception is thrown.

However, we can modify android's source code to avoid this problem. Using substring() method, we can split the uuid string into 5 parts. And then we can make the uuid.

The following codes worked for me:

public static UUID makeUuid(String uuidString) {
    String[] parts = {
            uuidString.substring(0, 7),
            uuidString.substring(9, 12),
            uuidString.substring(14, 17),
            uuidString.substring(19, 22),
            uuidString.substring(24, 35)
    };
    long m1 = Long.parseLong(parts[0], 16);
    long m2 = Long.parseLong(parts[1], 16);
    long m3 = Long.parseLong(parts[2], 16);
    long lsb1 = Long.parseLong(parts[3], 16);
    long lsb2 = Long.parseLong(parts[4], 16);
    long msb = (m1 << 32) | (m2 << 16) | m3;
    long lsb = (lsb1 << 48) | lsb2;
    return new UUID(msb, lsb);
}

Upvotes: 0

Peter Lawrey
Peter Lawrey

Reputation: 533500

Here is a workaround which avoids using this method,

String s = "0f14d0ab-9605-4a62-a9e4-5ed26688389b";
String s2 = s.replace("-", "");
UUID uuid = new UUID(
        new BigInteger(s2.substring(0, 16), 16).longValue(),
        new BigInteger(s2.substring(16), 16).longValue());
System.out.println(uuid);

prints

0f14d0ab-9605-4a62-a9e4-5ed26688389b

Upvotes: 19

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