uuid | 易学教程

How to find the UUID of serial port Bluetooth device?

阅读更多关于 How to find the UUID of serial port Bluetooth device?

问题 I want to receive data from the serial port bluetooth device to android phone. But i don't know the UUID of that device how to find the UUID of that device? 回答1: Extending what pwc said about the UUID being 0x1101, this is the 16 bit version of the UUID as far as I can tell. I could not work out how to instantiate an UUID with a 16 bit UUID. But as this post says you can do it by: private static final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805f9b34fb"); This worked for me

Android获取设备唯一码

阅读更多关于 Android获取设备唯一码

String uuid = ""; String serial = null; String m_szDevIDShort = "35" + Build.BOARD.length() % 10 + Build.BRAND.length() % 10 + Build.CPU_ABI.length() % 10 + Build.DEVICE.length() % 10 + Build.DISPLAY.length() % 10 + Build.HOST.length() % 10 + Build.ID.length() % 10 + Build.MANUFACTURER.length() % 10 + Build.MODEL.length() % 10 + Build.PRODUCT.length() % 10 + Build.TAGS.length() % 10 + Build.TYPE.length() % 10 + Build.USER.length() % 10; //13 位 try { serial = android.os.Build.class.getField("SERIAL").get(null).toString(); //API>=9 使用serial号 uuid = new UUID(m_szDevIDShort.hashCode(), serial

How can I get the UUID of my Android phone in an application?

阅读更多关于 How can I get the UUID of my Android phone in an application?

I'm looking for help to get the UUID of my Android phone. I have searched the net and found one potential solution but it is not working in the emulator. Here is the code: Class<?> c; try { c = Class.forName("android.os.SystemProperties"); Method get = c.getMethod("get", String.class); serial = (String) get.invoke(c, "ro.serialno"); Log.d("ANDROID UUID",serial); } catch (Exception e) { e.printStackTrace(); } Does anybody know why it isn't working, or have a better solution? pedr0 This works for me: TelephonyManager tManager = (TelephonyManager)getSystemService(Context.TELEPHONY_SERVICE);

How can I generate UUID in C#

阅读更多关于 How can I generate UUID in C#

问题 I am creating an .idl file programmatically. How do I create UUIDs for the interfaces and Methods Programmatically. Can I generate the UUID programmatically? 回答1: You are probably looking for System.Guid.NewGuid(). 回答2: Be careful: while the string representations for .NET Guid and (RFC4122) UUID are identical, the storage format is not. .NET trades in little-endian bytes for the first three Guid parts. If you are transmitting the bytes (for example, as base64), you can't just use Guid

Using Hibernate UUIDGenerator via annotations

阅读更多关于 Using Hibernate UUIDGenerator via annotations

问题 I'm using my uuid as following: @Id @GeneratedValue(generator = "uuid") @GenericGenerator(name = "uuid", strategy = "uuid") @Column(name = "uuid", unique = true) private String uuid; but I'm getting a smart Hibernate warning: Using org.hibernate.id.UUIDHexGenerator which does not generate IETF RFC 4122 compliant UUID values; consider using org.hibernate.id.UUIDGenerator instead So I want to switch to org.hibernate.id.UUIDGenerator , now my question is how should I tell it to Hibernate's

Collision probability of ObjectId vs UUID in a large distributed system

阅读更多关于 Collision probability of ObjectId vs UUID in a large distributed system

问题 Considering that an UUID rfc 4122 (16 bytes) is much larger than a MongoDB ObjectId (12 bytes), I am trying to find out how their collision probability compare. I know that is something around quite unlikely , but in my case most ids will be generated within a large number of mobile clients, not within a limited set of servers. I wonder if in this case, there is a justified concern . Compared to the normal case where all ids are generated by a small number of clients: It might take months to

Which UUID version to use?

阅读更多关于 Which UUID version to use?

问题 Which version of the UUID should you use? I saw a lot of threads explaining what each version entails, but I am having trouble figuring out what's best for what applications. 回答1: There are two different ways of generating a UUID. If you just need a unique ID, you want a version 1 or version 4. Version 1: This generates a unique ID based on a network card MAC address and a timer. These IDs are easy to predict (given one, I might be able to guess another one) and can be traced back to your

Is Secure.ANDROID_ID unique for each device?

阅读更多关于 Is Secure.ANDROID_ID unique for each device?

I am using this call: Secure.getString(getApplicationContext().getContentResolver(), Secure.ANDROID_ID); To get a UID for the device. I think I am getting the same ID from multiple devices though. Should this be possible? The ID in question is: 9774d56d682e549c and apparently there is an issue with several devices returning this ID http://code.google.com/p/android/issues/list?cursor=10603&updated=10603&ts=1295993403 ninjasense Check into this thread ,. However you should be careful as it's documented as "can change upon factory reset". Use at your own risk, and it can be easily changed on a

hive中一个好用的函数reflect

阅读更多关于 hive中一个好用的函数reflect

该函数可以支持hive调用java的内置函数， demo，可支持在hive表中生成uuid， regexp_replace(reflect("java.util.UUID", "randomUUID"), "-", "") uuid 还可以通过传字段生成求最大值等 select reflect("java.lang.Math","max",column1,column2) from test_udf 可以说有了该函数，hive和java之间简直畅通无阻，之前不知道有这么个函数，走了很多冤路。有了它，妈妈再也不用担心我搞不定任务大数据BI问题了，一个可以让领导也放心的函数来源： https://www.cnblogs.com/xinyumuhe/p/11328116.html

How to store uuid as number?

阅读更多关于 How to store uuid as number?

Based on the answer of question, UUID performance in MySQL , the person who answers suggest to store UUID as a number and not as a string. I'm not so sure how it can be done. Anyone could suggest me something? How my ruby code deal with that? David Bélanger If I understand correctly, you're using UUIDs in your primary column? People will say that a regular (integer) primary key will be faster , but there's another way using MySQL's dark side. In fact, MySQL is faster using binary than anything else when indexes are required. Since UUID is 128 bits and is written as hexadecimal, it's very easy