xcEduService01.zip_forget9uu_sendheo_xc-service_代码

package com.xuecheng.framework.utils; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.text.SimpleDateFormat; import java.util.Date; import java.util.concurrent.atomic.AtomicLong; /** * java edition of Twitter <b>Snowflake</b>, a network service for generating * unique ID numbers at high scale with some simple guarantees. * * https://github.com/twitter/snowflake */ public class Snowflake { private static Logger log = LoggerFactory.getLogger(Snowflake.class); // private static Logger /* * bits allocations for timeStamp, datacenterId, workerId and sequence */ private final long unusedBits = 1L; /** * 'time stamp' here is defined as the number of millisecond that have * elapsed since the {@link #epoch} given by users on {@link Snowflake} * instance initialization */ private final long timestampBits = 41L; private final long datacenterIdBits = 5L; private final long workerIdBits = 5L; private final long sequenceBits = 12L; /* * max values of timeStamp, workerId, datacenterId and sequence */ private final long maxDatacenterId = -1L ^ (-1L << datacenterIdBits); // 2^5-1 private final long maxWorkerId = -1L ^ (-1L << workerIdBits); // 2^5-1 private final long maxSequence = -1L ^ (-1L << sequenceBits); // 2^12-1 /** * left shift bits of timeStamp, workerId and datacenterId */ private final long timestampShift = sequenceBits + datacenterIdBits + workerIdBits; private final long datacenterIdShift = sequenceBits + workerIdBits; private final long workerIdShift = sequenceBits; /* * object status variables */ /** * reference material of 'time stamp' is '2016-01-01'. its value can't be * modified after initialization. */ private final long epoch = 1451606400000L; /** * data center number the process running on, its value can't be modified * after initialization. * <p> * max: 2^5-1 range: [0,31] */ private final long datacenterId; /** * machine or process number, its value can't be modified after * initialization. * <p> * max: 2^5-1 range: [0,31] * */ private final long workerId; /** * the unique and incrementing sequence number scoped in only one * period/unit (here is ONE millisecond). its value will be increased by 1 * in the same specified period and then reset to 0 for next period. * <p> * max: 2^12-1 range: [0,4095] */ private long sequence = 0L; /** the time stamp last snowflake ID generated */ private long lastTimestamp = -1L; /** * generate an unique and incrementing id * * @return id */ public synchronized long nextId() { long currTimestamp = timestampGen(); if (currTimestamp < lastTimestamp) { throw new IllegalStateException( String.format("Clock moved backwards. Refusing to generate id for %d milliseconds", lastTimestamp - currTimestamp)); } if (currTimestamp == lastTimestamp) { sequence = (sequence + 1) & maxSequence; if (sequence == 0) { // overflow: greater than max sequence currTimestamp = waitNextMillis(currTimestamp); } } else { // reset to 0 for next period/millisecond sequence = 0L; } // track and memo the time stamp last snowflake ID generated lastTimestamp = currTimestamp; return ((currTimestamp - epoch) << timestampShift) | // (datacenterId << datacenterIdShift) | // (workerId << workerIdShift) | // new line for nice looking sequence; } /** * @param datacenterId * data center number the process running on, value range: [0,31] * @param workerId * machine or process number, value range: [0,31] */ public Snowflake(long datacenterId, long workerId) { if (datacenterId > maxDatacenterId || datacenterId < 0) { throw new IllegalArgumentException( String.format("datacenter Id can't be greater than %d or less than 0", maxDatacenterId)); } if (workerId > maxWorkerId || workerId < 0) { throw new IllegalArgumentException( String.format("worker Id can't be greater than %d or less than 0", maxWorkerId)); } this.datacenterId = datacenterId; this.workerId = workerId; } /** * track the amount of calling {@link #waitNextMillis(long)} method */ private final AtomicLong waitCount = new AtomicLong(0); /** * @return the amount of calling {@link #waitNextMillis(long)} method */ public long getWaitCount() { return waitCount.get(); } /** * running loop blocking until next millisecond * * @param currTimestamp current time stamp * @return current time stamp in millisecond */ protected long waitNextMillis(long currTimestamp) { waitCount.incrementAndGet(); while (currTimestamp <= lastTimestamp) { currTimestamp = timestampGen(); } return currTimestamp; } /** * get current time stamp * * @return current time stamp in millisecond */ protected long timestampGen() { return System.currentTimeMillis(); } /** * show settings of Snowflake */ @Override public String toString() { return "Snowflake Settings [timestampBits=" + timestampBits + ", datacenterIdBits=" + datacenterIdBits + ", workerIdBits=" + workerIdBits + ", sequenceBits=" + sequenceBits + ", epoch=" + epoch + ", datacenterId=" + datacenterId + ", workerId=" + workerId + "]"; } public long getEpoch() { return this.epoch; } /** * extract time stamp, datacenterId, workerId and sequence number * information from the given id * * @param id * a snowflake id generated by this object * @return an array containing time stamp, datacenterId, workerId and * sequence number */ public long[] parseId(long id) { long[] arr = new long[5]; arr[4] = ((id & diode(unusedBits, timestampBits)) >> timestampShift); arr[0] = arr[4] + epoch; arr[1] = (id & diode(unusedBits + timestampBits, datacenterIdBits)) >> datacenterIdShift; arr[2] = (id & diode(unusedBits + timestampBits + datacenterIdBits, workerIdBits)) >> workerIdShift; arr[3] = (id & diode(unusedBits + timestampBits + datacenterIdBits + workerIdBits, sequenceBits)); return arr; } /** * extract and display time stamp, datacenterId, workerId and sequence * number information from the given id in humanization format * * @param id snowflake id in Long format * @return snowflake id in String format */ public String formatId(long id) { long[] arr = parseId(id); String tmf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS").format(new Date(arr[0])); return String.format("%s, #%d, @(%d,%d)", tmf, arr[3], arr[1], arr[2]); } /** * a diode is a long value whose left and right margin are ZERO, while * middle bits are ONE in binary string layout. it looks like a diode in * shape. * * @param offset * left margin position * @param length * offset+length is right margin position * @return a long value */ private long diode(long offset, long length) { int lb = (int) (64 - offset); int rb = (int) (64 - (of