短8位UUID思想其實借鑑微博短域名的生成方式，但是其重複概率過高，而且每次生成4個，需要隨即選取一個。

本演算法利用62個可列印字元，通過隨機生成32位UUID，由於UUID都為十六進位制，所以將UUID分成8組，每4個為一組，然後通過模62操作，結果作為索引取出字元，

這樣重複率大大降低。

經測試，在生成一千萬個數據也沒有出現重複，完全滿足大部分需求。程式碼貼出來供大家參考。

public static String[] chars = new String[] { "a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z","0","1","2","3","4","5","6","7","8","9","A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z" }; 
 
public static String generateShortUuid() {
 StringBuffer shortBuffer = new StringBuffer();
 String uuid = UUID.randomUUID().toString().replace("-","");
 for (int i = 0; i < 8; i++) {
 String str = uuid.substring(i * 4,i * 4 + 4);
 int x = Integer.parseInt(str,16);
 shortBuffer.append(chars[x % 0x3E]);
 }
 return shortBuffer.toString(); 
}

補充：生成 8 / 16 / 32 位的UUID

我就廢話不多說了，大家還是直接看例項吧~

 
import java.util.UUID; 
public class TestUUID { 
	// 得到16位的UUID-(數字)
	public static String getUUID_16() {
		int machineId = 1;// 最大支援1-9個叢集機器部署
 
		int hashCodeV = UUID.randomUUID().toString().hashCode();
		if (hashCodeV < 0) {// 有可能是負數
			hashCodeV = -hashCodeV;
		}
		String string = machineId + String.format("%015d",hashCodeV);
		return string;
	}
 
	// 得到32位的UUID-(數字)
	public static String getUUID_32() {
		return UUID.randomUUID().toString().replace("-","").toLowerCase();
	}
 
	//得到8位的UUID-(碼)
	public static String[] chars = new String[] { "a","Z" };
 
	public static String getUUID_8() {
		StringBuffer shortBuffer = new StringBuffer();
		String uuid = UUID.randomUUID().toString().replace("-","");
		for (int i = 0; i < 8; i++) {
			String str = uuid.substring(i * 4,i * 4 + 4);
			int x = Integer.parseInt(str,16);
			shortBuffer.append(chars[x % 0x3E]);
		}
		return shortBuffer.toString(); 
	}
 
	public static void main(String[] args) { 
		System.out.println(getUUID_8());
	} 
}

以上為個人經驗，希望能給大家一個參考，也希望大家多多支援我們。如有錯誤或未考慮完全的地方，望不吝賜教。