add getWorkerId stc

CHANGELOG.md

@@ -3,7 +3,7 @@
 
 -------------------------------------------------------------------------------------------------------------
 
-# 5.7.3 (2021-06-26)
+# 5.7.3 (2021-06-28)
 
 ### 🐣新特性
 * 【core   】     增加Convert.toSet方法（issue#I3XFG2@Gitee）
@@ -14,6 +14,7 @@
 * 【core   】     增加可自定义日期格式GlobalCustomFormat
 * 【jwt    】     JWT修改默认有序，并规定payload日期格式为秒数
 * 【json   】     增加JSONWriter
+* 【core   】     IdUtil增加getWorkerId和getDataCenterId（issueI3Y5NI@Gitee）
 
 ### 🐞Bug修复
 * 【json   】     修复XML转义字符的问题（issue#I3XH09@Gitee）

hutool-core/src/main/java/cn/hutool/core/lang/ObjectId.java

@@ -1,16 +1,16 @@
 package cn.hutool.core.lang;
 
-import java.lang.management.ManagementFactory;
-import java.net.NetworkInterface;
-import java.nio.ByteBuffer;
-import java.util.Enumeration;
-import java.util.concurrent.atomic.AtomicInteger;
-
 import cn.hutool.core.date.DateUtil;
 import cn.hutool.core.util.ClassLoaderUtil;
 import cn.hutool.core.util.RandomUtil;
+import cn.hutool.core.util.RuntimeUtil;
 import cn.hutool.core.util.StrUtil;
 
+import java.net.NetworkInterface;
+import java.nio.ByteBuffer;
+import java.util.Enumeration;
+import java.util.concurrent.atomic.AtomicInteger;
+
 /**
  * MongoDB ID生成策略实现<br>
  * ObjectId由以下几部分组成：
@@ -156,14 +156,7 @@ public class ObjectId {
 		// 进程ID初始化
 		int processId;
 		try {
-			// 获取进程ID
+			processId = RuntimeUtil.getPid();
-			final String processName =ManagementFactory.getRuntimeMXBean().getName();
-			final int atIndex = processName.indexOf('@');
-			if (atIndex > 0) {
-				processId = Integer.parseInt(processName.substring(0, atIndex));
-			} else {
-				processId = processName.hashCode();
-			}
 		} catch (Throwable t) {
 			processId = RandomUtil.randomInt();
 		}

hutool-core/src/main/java/cn/hutool/core/lang/Snowflake.java

@@ -1,6 +1,7 @@
 package cn.hutool.core.lang;
 
 import cn.hutool.core.date.SystemClock;
+import cn.hutool.core.util.IdUtil;
 import cn.hutool.core.util.StrUtil;
 
 import java.io.Serializable;
@@ -14,6 +15,7 @@ import java.util.Date;
  * snowflake的结构如下(每部分用-分开):<br>
  *
  * <pre>
+ * 符号位（1bit）- 时间戳相对值（41bit）- 数据中心标志（5bit）- 机器标志（5bit）- 递增序号（12bit）
  * 0 - 0000000000 0000000000 0000000000 0000000000 0 - 00000 - 00000 - 000000000000
  * </pre>
  * <p>
@@ -23,7 +25,8 @@ import java.util.Date;
  * <p>
  * 并且可以通过生成的id反推出生成时间,datacenterId和workerId
  * <p>
- * 参考：http://www.cnblogs.com/relucent/p/4955340.html
+ * 参考：http://www.cnblogs.com/relucent/p/4955340.html<br>
+ * 关于长度是18还是19的问题见：https://blog.csdn.net/unifirst/article/details/80408050
  *
  * @author Looly
  * @since 3.0.1
@@ -31,33 +34,63 @@ import java.util.Date;
 public class Snowflake implements Serializable {
 	private static final long serialVersionUID = 1L;
 
-	private final long twepoch;
+
-	private final long workerIdBits = 5L;
+	/**
+	 * 默认的起始时间，为Thu, 04 Nov 2010 01:42:54 GMT
+	 */
+	public static long DEFAULT_TWEPOCH = 1288834974657L;
+	/**
+	 * 默认回拨时间，2S
+	 */
+	public static long DEFAULT_TIME_OFFSET = 2000L;
+
+	private static final long WORKER_ID_BITS = 5L;
 	// 最大支持机器节点数0~31，一共32个
 	@SuppressWarnings({"PointlessBitwiseExpression", "FieldCanBeLocal"})
-	private final long maxWorkerId = -1L ^ (-1L << workerIdBits);
+	private static final long MAX_WORKER_ID = -1L ^ (-1L << WORKER_ID_BITS);
-	private final long dataCenterIdBits = 5L;
+	private static final long DATA_CENTER_ID_BITS = 5L;
 	// 最大支持数据中心节点数0~31，一共32个
 	@SuppressWarnings({"PointlessBitwiseExpression", "FieldCanBeLocal"})
-	private final long maxDataCenterId = -1L ^ (-1L << dataCenterIdBits);
+	private static final long MAX_DATA_CENTER_ID = -1L ^ (-1L << DATA_CENTER_ID_BITS);
-	// 序列号12位
+	// 序列号12位（表示只允许workId的范围为：0-4095）
-	private final long sequenceBits = 12L;
+	private static final long SEQUENCE_BITS = 12L;
 	// 机器节点左移12位
-	private final long workerIdShift = sequenceBits;
+	private static final long WORKER_ID_SHIFT = SEQUENCE_BITS;
 	// 数据中心节点左移17位
-	private final long dataCenterIdShift = sequenceBits + workerIdBits;
+	private static final long DATA_CENTER_ID_SHIFT = SEQUENCE_BITS + WORKER_ID_BITS;
 	// 时间毫秒数左移22位
-	private final long timestampLeftShift = sequenceBits + workerIdBits + dataCenterIdBits;
+	private static final long TIMESTAMP_LEFT_SHIFT = SEQUENCE_BITS + WORKER_ID_BITS + DATA_CENTER_ID_BITS;
 	// 序列掩码，用于限定序列最大值不能超过4095
 	@SuppressWarnings("FieldCanBeLocal")
-	private final long sequenceMask = ~(-1L << sequenceBits);// 4095
+	private static final long SEQUENCE_MASK = ~(-1L << SEQUENCE_BITS);// 4095
 
+	private final long twepoch;
 	private final long workerId;
 	private final long dataCenterId;
 	private final boolean useSystemClock;
+	// 允许的时钟回拨数
+	private final long timeOffset;
+
 	private long sequence = 0L;
 	private long lastTimestamp = -1L;
 
+	/**
+	 * 构造，使用自动生成的工作节点ID和数据中心ID
+	 */
+	public Snowflake() {
+		this(IdUtil.getWorkerId(IdUtil.getDataCenterId(MAX_DATA_CENTER_ID), MAX_WORKER_ID)
+				, IdUtil.getDataCenterId(MAX_DATA_CENTER_ID));
+	}
+
+	/**
+	 * 构造
+	 *
+	 * @param workerId     终端ID
+	 */
+	public Snowflake(long workerId) {
+		this(workerId, IdUtil.getDataCenterId(MAX_DATA_CENTER_ID));
+	}
+
 	/**
 	 * 构造
 	 *
@@ -87,21 +120,34 @@ public class Snowflake implements Serializable {
 	 * @since 5.1.3
 	 */
 	public Snowflake(Date epochDate, long workerId, long dataCenterId, boolean isUseSystemClock) {
+		this(epochDate, workerId, dataCenterId, isUseSystemClock, DEFAULT_TIME_OFFSET);
+	}
+
+	/**
+	 * @param epochDate        初始化时间起点（null表示默认起始日期）,后期修改会导致id重复,如果要修改连workerId dataCenterId，慎用
+	 * @param workerId         工作机器节点id
+	 * @param dataCenterId     数据中心id
+	 * @param isUseSystemClock 是否使用{@link SystemClock} 获取当前时间戳
+	 * @param timeOffset 允许时间回拨的毫秒数
+	 * @since 5.7.3
+	 */
+	public Snowflake(Date epochDate, long workerId, long dataCenterId, boolean isUseSystemClock, long timeOffset) {
 		if (null != epochDate) {
 			this.twepoch = epochDate.getTime();
 		} else{
 			// Thu, 04 Nov 2010 01:42:54 GMT
-			this.twepoch = 1288834974657L;
+			this.twepoch = DEFAULT_TWEPOCH;
 		}
-		if (workerId > maxWorkerId || workerId < 0) {
+		if (workerId > MAX_WORKER_ID || workerId < 0) {
-			throw new IllegalArgumentException(StrUtil.format("worker Id can't be greater than {} or less than 0", maxWorkerId));
+			throw new IllegalArgumentException(StrUtil.format("worker Id can't be greater than {} or less than 0", MAX_WORKER_ID));
 		}
-		if (dataCenterId > maxDataCenterId || dataCenterId < 0) {
+		if (dataCenterId > MAX_DATA_CENTER_ID || dataCenterId < 0) {
-			throw new IllegalArgumentException(StrUtil.format("datacenter Id can't be greater than {} or less than 0", maxDataCenterId));
+			throw new IllegalArgumentException(StrUtil.format("datacenter Id can't be greater than {} or less than 0", MAX_DATA_CENTER_ID));
 		}
 		this.workerId = workerId;
 		this.dataCenterId = dataCenterId;
 		this.useSystemClock = isUseSystemClock;
+		this.timeOffset = timeOffset;
 	}
 
 	/**
@@ -111,7 +157,7 @@ public class Snowflake implements Serializable {
 	 * @return 所属机器的id
 	 */
 	public long getWorkerId(long id) {
-		return id >> workerIdShift & ~(-1L << workerIdBits);
+		return id >> WORKER_ID_SHIFT & ~(-1L << WORKER_ID_BITS);
 	}
 
 	/**
@@ -121,7 +167,7 @@ public class Snowflake implements Serializable {
 	 * @return 所属数据中心
 	 */
 	public long getDataCenterId(long id) {
-		return id >> dataCenterIdShift & ~(-1L << dataCenterIdBits);
+		return id >> DATA_CENTER_ID_SHIFT & ~(-1L << DATA_CENTER_ID_BITS);
 	}
 
 	/**
@@ -131,7 +177,7 @@ public class Snowflake implements Serializable {
 	 * @return 生成的时间
 	 */
 	public long getGenerateDateTime(long id) {
-		return (id >> timestampLeftShift & ~(-1L << 41L)) + twepoch;
+		return (id >> TIMESTAMP_LEFT_SHIFT & ~(-1L << 41L)) + twepoch;
 	}
 
 	/**
@@ -142,8 +188,8 @@ public class Snowflake implements Serializable {
 	public synchronized long nextId() {
 		long timestamp = genTime();
 		if (timestamp < this.lastTimestamp) {
-			if(this.lastTimestamp - timestamp < 2000){
+			if(this.lastTimestamp - timestamp < timeOffset){
-				// 容忍2秒内的回拨，避免NTP校时造成的异常
+				// 容忍指定的回拨，避免NTP校时造成的异常
 				timestamp = lastTimestamp;
 			} else{
 				// 如果服务器时间有问题(时钟后退) 报错。
@@ -152,7 +198,7 @@ public class Snowflake implements Serializable {
 		}
 
 		if (timestamp == this.lastTimestamp) {
-			final long sequence = (this.sequence + 1) & sequenceMask;
+			final long sequence = (this.sequence + 1) & SEQUENCE_MASK;
 			if (sequence == 0) {
 				timestamp = tilNextMillis(lastTimestamp);
 			}
@@ -163,7 +209,10 @@ public class Snowflake implements Serializable {
 
 		lastTimestamp = timestamp;
 
-		return ((timestamp - twepoch) << timestampLeftShift) | (dataCenterId << dataCenterIdShift) | (workerId << workerIdShift) | sequence;
+		return ((timestamp - twepoch) << TIMESTAMP_LEFT_SHIFT)
+				| (dataCenterId << DATA_CENTER_ID_SHIFT)
+				| (workerId << WORKER_ID_SHIFT)
+				| sequence;
 	}
 
 	/**

hutool-core/src/main/java/cn/hutool/core/net/NetUtil.java

@@ -544,15 +544,7 @@ public class NetUtil {
 			return null;
 		}
 
-		byte[] mac = null;
+		final byte[] mac = getHardwareAddress(inetAddress);
-		try {
-			final NetworkInterface networkInterface = NetworkInterface.getByInetAddress(inetAddress);
-			if (null != networkInterface) {
-				mac = networkInterface.getHardwareAddress();
-			}
-		} catch (SocketException e) {
-			throw new UtilException(e);
-		}
 		if (null != mac) {
 			final StringBuilder sb = new StringBuilder();
 			String s;
@@ -570,6 +562,39 @@ public class NetUtil {
 		return null;
 	}
 
+	/**
+	 * 获得本机物理地址
+	 *
+	 * @return 本机物理地址
+	 * @since 5.7.3
+	 */
+	public static byte[] getLocalHardwareAddress() {
+		return getHardwareAddress(getLocalhost());
+	}
+
+	/**
+	 * 获得指定地址信息中的硬件地址
+	 *
+	 * @param inetAddress {@link InetAddress}
+	 * @return 硬件地址
+	 * @since 5.7.3
+	 */
+	public static byte[] getHardwareAddress(InetAddress inetAddress) {
+		if (null == inetAddress) {
+			return null;
+		}
+
+		try {
+			final NetworkInterface networkInterface = NetworkInterface.getByInetAddress(inetAddress);
+			if (null != networkInterface) {
+				return networkInterface.getHardwareAddress();
+			}
+		} catch (SocketException e) {
+			throw new UtilException(e);
+		}
+		return null;
+	}
+
 	/**
 	 * 获取主机名称，一次获取会缓存名称
 	 *

hutool-core/src/main/java/cn/hutool/core/util/IdUtil.java

@@ -1,9 +1,11 @@
 package cn.hutool.core.util;
 
+import cn.hutool.core.exceptions.UtilException;
 import cn.hutool.core.lang.ObjectId;
 import cn.hutool.core.lang.Singleton;
 import cn.hutool.core.lang.Snowflake;
 import cn.hutool.core.lang.UUID;
+import cn.hutool.core.net.NetUtil;
 
 /**
  * ID生成器工具类，此工具类中主要封装：
@@ -134,4 +136,53 @@ public class IdUtil {
 	public static Snowflake getSnowflake(long workerId, long datacenterId) {
 		return Singleton.get(Snowflake.class, workerId, datacenterId);
 	}
+
+	/**
+	 * 获取数据中心ID<br>
+	 * 数据中心ID依赖于本地网卡MAC地址。
+	 * <p>
+	 * 此算法来自于mybatis-plus#Sequence
+	 * </p>
+	 *
+	 * @param maxDatacenterId 最大的中心ID
+	 * @return 数据中心ID
+	 * @since 5.7.3
+	 */
+	public static long getDataCenterId(long maxDatacenterId) {
+		long id = 1L;
+		final byte[] mac = NetUtil.getLocalHardwareAddress();
+		if (null != mac) {
+			id = ((0x000000FF & (long) mac[mac.length - 2])
+					| (0x0000FF00 & (((long) mac[mac.length - 1]) << 8))) >> 6;
+			id = id % (maxDatacenterId + 1);
+		}
+
+		return id;
+	}
+
+	/**
+	 * 获取机器ID，使用进程ID配合数据中心ID生成<br>
+	 * 机器依赖于本进程ID或进程名的Hash值。
+	 *
+	 * <p>
+	 * 此算法来自于mybatis-plus#Sequence
+	 * </p>
+	 *
+	 * @param datacenterId 数据中心ID
+	 * @param maxWorkerId  最大的机器节点ID
+	 * @since 5.7.3
+	 */
+	public static long getWorkerId(long datacenterId, long maxWorkerId) {
+		final StringBuilder mpid = new StringBuilder();
+		mpid.append(datacenterId);
+		try {
+			mpid.append(RuntimeUtil.getPid());
+		} catch (UtilException igonre) {
+			//ignore
+		}
+		/*
+		 * MAC + PID 的 hashcode 获取16个低位
+		 */
+		return (mpid.toString().hashCode() & 0xffff) % (maxWorkerId + 1);
+	}
 }

hutool-core/src/main/java/cn/hutool/core/util/RuntimeUtil.java

@@ -1,5 +1,6 @@
 package cn.hutool.core.util;
 
+import cn.hutool.core.exceptions.UtilException;
 import cn.hutool.core.io.IORuntimeException;
 import cn.hutool.core.io.IoUtil;
 import cn.hutool.core.text.StrBuilder;
@@ -7,6 +8,7 @@ import cn.hutool.core.text.StrBuilder;
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
+import java.lang.management.ManagementFactory;
 import java.nio.charset.Charset;
 import java.util.ArrayList;
 import java.util.List;
@@ -279,8 +281,29 @@ public class RuntimeUtil {
 		return getMaxMemory() - getTotalMemory() + getFreeMemory();
 	}
 
+	/**
+	 * 获取当前进程ID，首先获取进程名称，读取@前的ID值，如果不存在，则读取进程名的hash值
+	 *
+	 * @return 进程ID
+	 * @throws UtilException 进程名称为空
+	 * @since 5.7.3
+	 */
+	public static int getPid() throws UtilException {
+		final String processName = ManagementFactory.getRuntimeMXBean().getName();
+		if (StrUtil.isBlank(processName)) {
+			throw new UtilException("Process name is blank!");
+		}
+		final int atIndex = processName.indexOf('@');
+		if (atIndex > 0) {
+			return Integer.parseInt(processName.substring(0, atIndex));
+		} else {
+			return processName.hashCode();
+		}
+	}
+
 	/**
 	 * 处理命令，多行命令原样返回，单行命令拆分处理
+	 *
 	 * @param cmds 命令
 	 * @return 处理后的命令
 	 */

hutool-core/src/test/java/cn/hutool/core/util/IdUtilTest.java

@@ -134,4 +134,10 @@ public class IdUtilTest {
 		}
 		Assert.assertEquals(threadCount * idCountPerThread, set.size());
 	}
+
+	@Test
+	public void getDataCenterIdTest(){
+		final long dataCenterId = IdUtil.getDataCenterId(Long.MAX_VALUE);
+		Assert.assertTrue(dataCenterId > 1);
+	}
 }