content: package com.xxl.job.admin.core.route.strategy;
  
  import com.xxl.job.admin.core.route.ExecutorRouter;
  import com.xxl.job.core.biz.model.ReturnT;
  import com.xxl.job.core.biz.model.TriggerParam;
  
  import java.util.List;
  import java.util.Random;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.concurrent.ConcurrentMap;
  import java.util.concurrent.atomic.AtomicInteger;
  
  /**
   * Created by xuxueli on 17/3/10.
   */
  public class ExecutorRouteRound extends ExecutorRouter {
  
  	private static ConcurrentMap<Integer, AtomicInteger> routeCountEachJob = new ConcurrentHashMap<>();
  
  	private static long CACHE_VALID_TIME = 0;
  
  	private static int count(int jobId) {
  		// cache clear
  		if (System.currentTimeMillis() > CACHE_VALID_TIME) {
  			routeCountEachJob.clear();
  			CACHE_VALID_TIME = System.currentTimeMillis() + 1000 * 60 * 60 * 24;
  		}
  
  		AtomicInteger count = routeCountEachJob.get(jobId);
  		if (count == null || count.get() > 1000000) {
  			// 初始化时主动Random一次，缓解首次压力
  			count = new AtomicInteger(new Random().nextInt(100));
  		}
  		else {
  			// count++
  			count.addAndGet(1);
  		}
  		routeCountEachJob.put(jobId, count);
  		return count.get();
  	}
  
  	@Override
  	public ReturnT<String> route(TriggerParam triggerParam, List<String> addressList) {
  		String address = addressList.get(count(triggerParam.getJobId()) % addressList.size());
  		return new ReturnT<String>(address);
  	}
  
  }
  