springboot多节点应用里的雪花算法唯一性详解

apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-app
spec:
  replicas: 3
  selector:
    matchLabels:
      app: my-app
  template:
    metadata:
      labels:
        app: my-app
    spec:
      containers:
      - name: my-container
        image: my-image:latest
        env:
        - name: POD_NAME
          valueFrom:
            fieldRef:
              fieldPath: metadata.name  # 获取当前 Pod 的名称

public static int stringToNumber(String input) {
        // 使用CRC32计算字符串的哈希值
        CRC32 crc = new CRC32();
        byte[] bytes = input.getBytes(StandardCharsets.UTF_8);
        crc.update(bytes);
        // 获取哈希值并限制在0到1023之间
        long hashValue = crc.getValue();
        return (int) (hashValue % 1024);
    }

/**
	 * 获取机器码.
	 * @return
	 */
	public static String getUniqueMachineId() {
		StringBuilder uniqueId = new StringBuilder();
		try {
			// 获取本机的IP地址
			InetAddress localHost = InetAddress.getLocalHost();
			uniqueId.append(localHost.getHostAddress()).append("_");
			// 获取网络接口并获取MAC地址
			Enumeration<NetworkInterface> networkInterfaces = NetworkInterface.getNetworkInterfaces();
			while (networkInterfaces.hasMoreElements()) {
				NetworkInterface networkInterface = networkInterfaces.nextElement();
				byte[] mac = networkInterface.getHardwareAddress();
				if (mac != null) {
					for (int i = 0; i < mac.length; i++) {
						uniqueId.append(String.format("%02X", mac[i]));
						if (i < mac.length - 1) {
							uniqueId.append("-");
						}
					}
					uniqueId.append("_");
				}
			}
			// 添加系统信息作为补充
			String osName = System.getProperty("os.name");
			String osVersion = System.getProperty("os.version");
			String userName = System.getProperty("user.name");
			uniqueId.append(osName).append("_").append(osVersion).append("_").append(userName);
		}
		catch (Exception e) {
			e.printStackTrace();
		}
		return uniqueId.toString();
	}

@Slf4j
public class IdUtils {
	static SnowFlakeGenerator snowFlakeGenerator;
	public static String generateId() {
		if (snowFlakeGenerator == null) {
			long podNameCode = stringToNumber(Optional.ofNullable(System.getenv("POD_NAME")).orElse(stringToNumber(getUniqueMachineId())));
			log.debug("podNameCode:{}", podNameCode);
			snowFlakeGenerator = new SnowFlakeGenerator(podNameCode);
		}
		return snowFlakeGenerator.hexNextId();
	}