uuid

问题 I found that jackson comes equipped with a UUID serizlizer/deserializer that can be used like this: @Data @NoArgsConstructor public class MyClass { @JsonSerialize(using=UUIDSerializer.class) @JsonDeserialize(using=UUDIDeserializer.class) private UUID myUUID; } And then using ObjectMapper on MyClass will correctly serialize/deserialize the myUUID field. However, my class has a set of UUIDs that I want to serialize. I tried annotating the field the same way as above, but it complains that Set

问题 Suppose two Android mobile phones are paired via Bluetooth and connection is established. How to programmatically determine at the client whether the remote device (the server) supports Bluetooth profiles such as PBAP? And if it does support it, then how to programmatically initiate a PBAP session with the remote device? I have extensively searched the net and so far have been unable to find API support and documentation for the same. Edit Would fetching the remote device's UUIDs be of any

问题 Apple since iOS7 ha deprecated and unavailable the use of the property -uniqueIdentifier . The other properties -identifierForVendor and -advertisingIdentifier have the big problem that they change the value after uninstalling and reinstalling the app. I need that value to identify uniquely the device connected to the server. The app will be distributed only internally using an enterprise account, so no problem for the review process. Is there a private a method to get it? [UPDATE WITH SOME

问题 This question already has answers here : How do I unit test code which uses Java UUID? (4 answers) Closed 2 years ago . I'm trying to test a Web Service method which connects to a SQL Server Database which contains JCR nodes, as we're using JackRabbit. The method looks like: public String addDocumentByJson(String fileName, byte[] fileContent, int status, String userName, String jsonProperties) { UUID id = UUID.randomUUID(); // It does a bunch of operations here return jsonResult; } Where

问题 I have a path to a partition. How can I retrieve UUID of that partition programatically without using terminal commands? An example will be more helpful. 回答1: You can use the Disk Arbitration framework (Apple reference). There is also a good summary at this blog by Chris Suter. You can get the UUID by using the kDADiskDescriptionMediaUUIDKey. Aaron Burghardt described it well in this mailing list thread. Here is a quote from that link: Once you have the DADisk, use DADiskCopyDescription to

问题 I have a postgresql 9 installation on windows, which doesn't have built in uuid generator. There is OSSD package, which can be bound to postgresql as uuid generator, but it's for *nix only (I think). How can I generate uuid in windows postgresql? 回答1: The one-click installer from EnterpriseDB does have it. The DLL is called "uuid-ossp.dll" and resides in "(Postgres' installation directory)\lib" and the installation SQL script is called "uuid-ossp.sql" and resides in "(Postgres' installation

问题 I have a UUID that I was thinking of packing into a struct using UUID.int, which turns it into a 128-bit integer. But none of the struct format characters are large enough to store it, how to go about doing this? Sample code: s = struct.Struct('L') unique_id = uuid.uuid4() tuple = (unique_id.int) packed = s.pack(*tuple) The problem is, struct format 'L' is only 4 bytes...I need to store 16. Storing it as a 32-char string is a bit much. 回答1: It is a 128-bit integer, what would you expect it to

问题 One of my Rails migrations uses a uuid as the primary key. The Postgres extension gen_random_uuid() should solve this issue, but I continue to get the error after installing the relevant extension ( uuid-ossp ). 回答1: The issue was that the uuid-ossp extension was being blown away with the database each time I dropped the db as part of a reset and migration (e.g. rake db:drop db:create db:migrate ). The fix is to create a migration that's run before all other migrations which enables the

问题 I am using Javas UUID and need to convert a UUID to a byte Array. Strangely the UUID Class does not provide a "toBytes()" method. I already found out about the two methods: UUID.getMostSignificantBits() and UUID.getLeasSignificantBits() But how to get this into a byte array? the result should be a byte[] with those tow values. I somehow need to do Bitshifting but, how? update: I found: ByteBuffer byteBuffer = MappedByteBuffer.allocate(2); byteBuffer.putLong(uuid.getMostSignificantBits());

问题 I couldn't find a self-contained UUID5 implementation for Java, so I tried rolling this solution below. It passes some of my unit tests but fails others. Any obvious bugs in this? public static UUID UUID5(UUID namespace, String name) { MessageDigest md; try { md = MessageDigest.getInstance("SHA-1"); } catch (NoSuchAlgorithmException nsae) { throw new InternalError("SHA-1 not supported"); } byte[] namespaceBytes = ByteBuffer.allocate(16).putLong(namespace.getMostSignificantBits()).putLong