执行器LFU策略功能实现

xxl-job-admin/src/main/java/com/xxl/job/admin/core/route/ExecutorRouter.java

@@ -25,7 +25,7 @@ public abstract class ExecutorRouter {
 
 
         for (int i = 0; i < 100; i++) {
-            String ret = ExecutorRouter.route(666, new ArrayList<String>(Arrays.asList("127.0.0.1:0000", "127.0.0.1:2222", "127.0.0.1:3333")), ExecutorRouteStrategyEnum.LEAST_RECENTLY_USED.name());
+            String ret = ExecutorRouter.route(666, new ArrayList<String>(Arrays.asList("127.0.0.1:0000", "127.0.0.1:2222", "127.0.0.1:3333")), ExecutorRouteStrategyEnum.LEAST_FREQUENTLY_USED.name());
             System.out.println(ret);
         }
 

xxl-job-admin/src/main/java/com/xxl/job/admin/core/route/strategy/ExecutorRouteLFU.java

@@ -2,7 +2,8 @@ package com.xxl.job.admin.core.route.strategy;
 
 import com.xxl.job.admin.core.route.ExecutorRouter;
 
-import java.util.ArrayList;
+import java.util.*;
+import java.util.concurrent.ConcurrentHashMap;
 
 /**
  * 单个JOB对应的每个执行器，使用频率最低的优先被选举
@@ -13,12 +14,44 @@ import java.util.ArrayList;
  */
 public class ExecutorRouteLFU extends ExecutorRouter {
 
+    private static ConcurrentHashMap<Integer, HashMap<String, Integer>> jobLfuMap = new ConcurrentHashMap<Integer, HashMap<String, Integer>>();
+    private static long CACHE_VALID_TIME = 0;
+
     @Override
     public String route(int jobId, ArrayList<String> addressList) {
 
-        // TODO
+        // cache clear
+        if (System.currentTimeMillis() > CACHE_VALID_TIME) {
+            jobLfuMap.clear();
+            CACHE_VALID_TIME = System.currentTimeMillis() + 1000*60*60*24;
+        }
+
+        // lfu item init
+        HashMap<String, Integer> lfuItemMap = jobLfuMap.get(jobId);     // Key排序可以用TreeMap+构造入参Compare；Value排序暂时只能通过ArrayList；
+        if (lfuItemMap == null) {
+            lfuItemMap = new HashMap<String, Integer>();
+            jobLfuMap.put(jobId, lfuItemMap);
+        }
+        for (String address: addressList) {
+            if (!lfuItemMap.containsKey(address)) {
+                lfuItemMap.put(address, 0);
+            }
+        }
+
+        // load least userd count address
+        List<Map.Entry<String, Integer>> lfuItemList = new ArrayList<Map.Entry<String, Integer>>(lfuItemMap.entrySet());
+        Collections.sort(lfuItemList, new Comparator<Map.Entry<String, Integer>>() {
+            @Override
+            public int compare(Map.Entry<String, Integer> o1, Map.Entry<String, Integer> o2) {
+                return o1.getValue().compareTo(o2.getValue());
+            }
+        });
+
+        Map.Entry<String, Integer> addressItem = lfuItemList.get(0);
+        String minAddress = addressItem.getKey();
+        addressItem.setValue(addressItem.getValue() + 1);
 
-        return addressList.get(0);
+        return addressItem.getKey();
     }
 
 }