视频056~(完成雪花算法)

beacon-api/src/main/java/com/mashibing/api/ApiStarterApp.java

@@ -4,6 +4,7 @@ import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
 import org.springframework.cloud.openfeign.EnableFeignClients;
+import org.springframework.context.annotation.ComponentScan;
 
 /**
  * @author zjw
@@ -12,6 +13,10 @@ import org.springframework.cloud.openfeign.EnableFeignClients;
 @SpringBootApplication
 @EnableDiscoveryClient
 @EnableFeignClients
+@ComponentScan(basePackages = {
+        "com.mashibing.api",
+        "com.mashibing.common"
+})
 public class ApiStarterApp {
 
     public static void main(String[] args) {

beacon-api/src/main/java/com/mashibing/api/controller/SmsController.java

@@ -6,6 +6,7 @@ import com.mashibing.api.util.R;
 import com.mashibing.api.vo.ResultVO;
 import com.mashibing.common.enums.ExceptionEnums;
 import com.mashibing.common.model.StandardSubmit;
+import com.mashibing.common.util.SnowFlakeUtil;
 import lombok.extern.slf4j.Slf4j;
 import org.apache.commons.lang.StringUtils;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -30,6 +31,10 @@ import javax.servlet.http.HttpServletRequest;
 @RefreshScope
 public class SmsController {
 
+    @Autowired
+    private SnowFlakeUtil snowFlakeUtil;
+
+
     /**
      * 客户端IP地址的请求头信息，多个用','隔开。
      */
@@ -80,6 +85,9 @@ public class SmsController {
         //=========================调用策略模式的校验链=========================================
         checkFilterContext.check(submit);
 
+        //========================基于雪花算法生成唯一id，并添加到StandardSubmit对象中=========================================
+        submit.setSequenceId(snowFlakeUtil.nextId());
+
         //=========================发送到MQ，交给策略模块处理=========================================
         return R.ok();
     }

beacon-common/src/main/java/com/mashibing/common/enums/ExceptionEnums.java

@@ -16,7 +16,8 @@ public enum ExceptionEnums {
     ERROR_MOBILE(-5,"手机号格式不正确"),
     BALANCE_NOT_ENOUGH(-6,"客户余额不足"),
     PARAMETER_ERROR(-10,"参数不合法！"),
-    SNOWFLAKE_OUT_OF_RANGE(-11,"雪花算法的机器id或服务id超出最大范围！")
+    SNOWFLAKE_OUT_OF_RANGE(-11,"雪花算法的机器id或服务id超出最大范围！"),
+    SNOWFLAKE_TIME_BACK(-12,"雪花算法的服务器出现时间回拨问题！"),
     ;
     private Integer code;
 

beacon-common/src/main/java/com/mashibing/common/util/SnowFlakeUtil.java

@@ -2,15 +2,10 @@ package com.mashibing.common.util;
 
 import com.mashibing.common.enums.ExceptionEnums;
 import com.mashibing.common.exception.ApiException;
-import lombok.extern.slf4j.Slf4j;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.stereotype.Component;
 
 import javax.annotation.PostConstruct;
-import java.time.Instant;
-import java.time.LocalDate;
-import java.time.ZoneId;
-import java.util.Date;
 
 /**
  * 雪花算法生成全局唯一ID
@@ -24,7 +19,6 @@ import java.util.Date;
  * @description
  */
 @Component
-@Slf4j
 public class SnowFlakeUtil {
 
     /**
@@ -98,16 +92,64 @@ public class SnowFlakeUtil {
     /**
      * 时间戳需要位移的位数
      */
-    private long timestampShift = sequenceBits + serviceIdBits + maxMachineId;
-
-
-
-
-
+    private long timestampShift = sequenceBits + serviceIdBits + machineIdBits;
 
+    /**
+     *  序列的最大值
+     */
+    private long maxSequenceId = -1 ^ (-1 << sequenceBits);
 
+    /**
+     * 记录最近一次获取id的时间
+     */
+    private long lastTimestamp = -1;
 
+    /**
+     *  获取系统时间毫秒值
+     * @return
+     */
+    private long timeGen(){
+        return System.currentTimeMillis();
+    }
 
 
+    public synchronized long nextId(){
+        //1、 拿到当前系统时间的毫秒值
+        long timestamp = timeGen();
+        // 避免时间回拨造成出现重复的id
+        if(timestamp < lastTimestamp){
+            // 说明出现了时间回拨
+            System.out.println("当前服务出现时间回拨！！！");
+            throw new ApiException(ExceptionEnums.SNOWFLAKE_TIME_BACK);
+        }
 
+        //2、 判断当前生成id的时间和上一次生成的时间
+        if(timestamp == lastTimestamp){
+            // 同一毫秒值生成id
+            sequence = (sequence + 1) & maxSequenceId;
+            // 0000 10100000 :sequence
+            // 1111 11111111 :maxSequenceId
+            if(sequence == 0){
+                // 进到这个if，说明已经超出了sequence序列的最大取值范围
+                // 需要等到下一个毫秒再做回来生成具体的值
+                timestamp = timeGen();
+                while(timestamp <= lastTimestamp){
+                    // 时间还没动。
+                    timestamp = timeGen();
+                }
+            }
+        }else{
+            // 另一个时间点生成id
+            sequence = 0;
+        }
+        //3、重新给lastTimestamp复制
+        lastTimestamp = timestamp;
+
+        //4、计算id，将几位值拼接起来。  41bit位的时间，5位的机器，5位的服务 ，12位的序列
+        return  ((timestamp - timeStart) << timestampShift) |
+                (machineId << machineIdShift) |
+                (serviceId << serviceIdShift) |
+                sequence &
+                Long.MAX_VALUE;
+    }
 }