1、shardingsphere是一个开源系统，提供了一套分布式数据库解决方案。
而这里面肯定会涉及到如何生成系统中不重复的主键id
2、官方文档地址：https://shardingsphere.apache.org/document/current/cn/features/sharding/concept/key-generator/
3、上代码
1 /** 2 * @author jijiecong 3 * @version 1.0 4 * @date 2021/12/1 14:21 5 * @description 雪花算法生成id工具类 6 */ 7 @Slf4j 8 public class SnowFlakeUtil { 9 10 private static final String WORK_ID_KEY = "worker.id"; 11 12 private static SnowflakeShardingKeyGenerator keyGenerator; 13 14 /** 15 * 单例 16 */ 17 public static SnowflakeShardingKeyGenerator getInstance() { 18 19 if (keyGenerator == null) { 20 21 synchronized (SnowFlakeUtil.class) { 22 23 // 双重校验 24 if (keyGenerator == null) { 25 26 keyGenerator = new SnowflakeShardingKeyGenerator(); 27 28 // 设置workId，注意一定要转换成String再put进去 29 keyGenerator.getProperties().put(WORK_ID_KEY, getWorkId()); 30 } 31 32 } 33 34 } 35 36 return keyGenerator; 37 } 38 39 /** 40 * 获取id 41 * 42 * @return id 43 */ 44 public static Long getId() { 45 46 Long id = (Long) getInstance().generateKey(); 47 48 log.info("___此次生成的id为：{}", id); 49 50 return id; 51 52 } 53 54 /** 55 * 获取workId，保证分布式服务下每台机器都不同 56 * 使用机器ip都最后3位作为workId 57 * 58 * @return workId 59 */ 60 public static String getWorkId() { 61 String workId = "0"; 62 63 try { 64 65 InetAddress inetAddress = InetAddress.getLocalHost(); 66 67 String localIp = StringUtils.isBlank(inetAddress.getHostAddress()) ? 68 null : inetAddress.getHostAddress().trim(); 69 70 if (StringUtils.isNotBlank(localIp) && localIp.contains(".")) { 71 72 String[] ipArray = localIp.split("\\."); 73 74 workId = ipArray[ipArray.length - 1]; 75 76 log.info("___workId:{}", workId); 77 78 } 79 80 } catch (Exception e) { 81 82 log.error("获取workId失败", e); 83 84 } 85 86 return workId; 87 } 88 89 public static void main(String[] args) { 90 long id = SnowFlakeUtil.getId(); 91 System.out.println(id); 92 } 93 }
4、踩坑
4.1、在设置properities时要转成String再设置，Properities源码
1 /** 2 * Searches for the property with the specified key in this property list. 3 * If the key is not found in this property list, the default property list, 4 * and its defaults, recursively, are then checked. The method returns 5 * {@code null} if the property is not found. 6 * 7 * @param key the property key. 8 * @return the value in this property list with the specified key value. 9 * @see #setProperty 10 * @see #defaults 11 */ 12 public String getProperty(String key) { 13 Object oval = super.get(key); 14 String sval = (oval instanceof String) ? (String)oval : null; 15 return ((sval == null) && (defaults != null)) ? defaults.getProperty(key) : sval; 16 }