uuid

This question already has an answer here: Unique Identification of iOS device for iOS 7.0 and above 6 answers In my iOS app, I have to restrict the user to use iOS app per device. To do this I found a solution that we can use the UUID (Universally Unique Identifier) or UDID (Unique Device Identifier) . But according to this answer I can't use UUID, because if app gets deleted or reinstalled UUID has been getting changed and I don't want this. Also Apple rejects apps if app uses UDID . Is there any way to identify iOS device uniquely. Apple has done away with the approach of UDIDs and will

微信推送报警消息实现 目录 1 前言... 2 1.1 背景... 2 1.2 现有技术对比... 2 2 总体流程... 2 3 微信网页接口解析... 3 3.1 获取用户uuid. 3 3.2 获取二维码图片... 4 3.3 轮询检测用户是否登录... 4 3.4 重定向url登录微信并获取公参... 5 3.5 微信初始化... 5 3.6 获取联系人列表... 11 3.7 批量获取联系人详情... 13 3.8 检测是否有微信消息... 16 3.9 获取最新消息... 17 3.10 通过微信推送报警消息... 22 3.11 上传文件到微信服务器... 24 3.12 发送图片... 27 4 一些状态码code值的说明... 28 4.1 BaseResponse里的Ret 28 4.2 同步消息检查返回值中retcode和selector 28 4.3 返回消息类型... 29 5 实现操作步骤... 30 6 技术制约... 32 7 技术应用推广... 32 1 前言 1.1 背景 微信已经普遍被大家应用，而且手机微信方便快捷，可以随时随地的接受消息。目前项目中有需求通过微信推送报警消息。但是微信没有对外接口，无法实现报警推送。微信的方便快捷没有办法使用。可以通过微信的网页接口来实现微信的登录、获取好友信息、发送微信消息、获取微信消息等； 1.2

Does java.util.UUID.randomUUID().toString() length always equal to 36? I was not able to find info on that. Here it is said only the following: public static UUID randomUUID() Static factory to retrieve a type 4 (pseudo randomly generated) UUID. The UUID is generated using a cryptographically strong pseudo random number generator. Returns: A randomly generated UUID And that type 4 tells me nothing. I do not know what type 4 means in the case. Does java.util.UUID.randomUUID().toString() length always equal to 36? Yes!! it is. A UUID actually a 128 bit value (2 long). To represent 128 bit into

Question is How do I convert ByteArray to GUID. Previously I converted my guid to byte array, and after some transaction I need my guid back from byte array. How do I do that. Although irrelevant but conversion from Guid to byte[] is as below public static byte[] getByteArrayFromGuid(String str) { UUID uuid = UUID.fromString(str); ByteBuffer bb = ByteBuffer.wrap(new byte[16]); bb.putLong(uuid.getMostSignificantBits()); bb.putLong(uuid.getLeastSignificantBits()); return bb.array(); } but how do I convert it back?? I tried this method but its not returning me same value public static String

This question already has an answer here: How good is Java's UUID.randomUUID? 10 answers I need to create some uniques files in Java and i plan to use UUID.randomUUID to generate their names. Is there any chance to get a collision for this? Should i do something like bellow os I shouldn't worry about this? Integer attemptsToGenerateUUID = 1; while (true) { UUID fileUUID = UUID.randomUUID(); if (fileDoesNotExistwith this UUID name) { save file; break; } attemptsToGenerateUUID += 1; if (attemptsToGenerateUUID > 64) { return false; } } According to wikipedia , regarding the probability of

I have a uuid field (not a primary key). The generated migration is: from __future__ import unicode_literals from django.db import migrations, models import uuid class Migration(migrations.Migration): dependencies = [ .... ] operations = [ ... migrations.AddField( model_name='device', name='uuid', field=models.UUIDField(default=uuid.uuid4, unique=True), ), ... ] But when doing python manage.py migrate it is crashing with: django.db.utils.IntegrityError: could not create unique index "restaurants_device_uuid_key" DETAIL: Key (uuid)=(f3858ded-b8e0-4ac0-8436-8a61b10efc73) is duplicated. Strangely

Well, what is one? It's an identification number that will uniquely identify something. The idea being that that id number will be universally unique. Thus, no two things should have the same uuid. In fact, if you were to generate 10 trillion uuids, there would be something along the lines of a .00000006 chance of two uuids being the same. Bob Aman Standardized identifiers UUID s are defined in RFC 4122 . They're Universally Unique IDentifiers, that can be generated without the use of a centralized authority. There are four major types of UUIDs which are used in slightly different scenarios.