Java-生成唯一ID（Sequence）

旧城等待， 2021-09-28 01:20 759阅读 0赞

package com.bootdo.common.utils;
    
    import org.springframework.stereotype.Component;
    
    import java.util.concurrent.locks.Lock;
    import java.util.concurrent.locks.ReentrantLock;
    
    /**
     * @author 张子布
     * @version 1.0
     * @date 2018/8/28
     * @explain:
     */
    @Component
    public class Sequence {
        private static final long ONE_STEP = 10;
        private static final Lock LOCK = new ReentrantLock();
        private static long lastTime = System.currentTimeMillis();
        private static short lastCount = 0;
        private static int count = 0;
    
        @SuppressWarnings("finally")
        public static String nextId() {
            LOCK.lock();
            try {
                if (lastCount == ONE_STEP) {
                    boolean done = false;
                    while (!done) {
                        long now = System.currentTimeMillis();
                        if (now == lastTime) {
                            try {
                                Thread.currentThread();
                                Thread.sleep(1);
                            } catch (java.lang.InterruptedException e) {
                            }
                            continue;
                        } else {
                            lastTime = now;
                            lastCount = 0;
                            done = true;
                        }
                    }
                }
                count = lastCount++;
            } finally {
                LOCK.unlock();
                return lastTime + "" + String.format("%03d", count);
            }
        }
    
        //获得batchNo批次号
        @SuppressWarnings({"finally"})
        public static String getBatchNo() {
            LOCK.lock();
            try {
                if (lastCount == ONE_STEP) {
                    boolean done = false;
                    while (!done) {
                        long now = System.currentTimeMillis();
                        if (now == lastTime) {
                            try {
                                Thread.currentThread();
                                Thread.sleep(1);
                            } catch (java.lang.InterruptedException e) {
                            }
                            continue;
                        } else {
                            lastTime = now;
                            lastCount = 0;
                            done = true;
                        }
                    }
                }
                count = lastCount++;
            } finally {
                LOCK.unlock();
                String str = lastTime + "" + String.format("%03d", count);
                String batchNo = "C"+str.substring(1);
                return batchNo;
            }
        }
    
        public static void main(String[] args) {
            //测试
    
                System.out.println(nextId());
    
        }
    }