merge

boot-service/src/main/java/com/xwbing/demo/LambdaDemo.java

@@ -83,11 +83,11 @@ public class LambdaDemo {
             reduce = optional.get();
         }
         //异步回调
-        List<JSONObject> sysUsers = CompletableFuture.supplyAsync(LambdaDemo::getList).join();
+        List<JSONObject> sysUsers = CompletableFuture.supplyAsync(LambdaDemo::getList).join();//线程等待,效果等同于get(),会拋出CompletionException
     }
 
     /**
-     * 遍历集合，集合里数据还要进行复杂操作，导致速度很慢，可以用异步
+     * 遍历集合，集合里数据还要进行复杂操作，导致速度很慢，可以用异步(无法保证顺序)
      */
     public List<JSONObject> supplyAsync() {
         List<JSONObject> list = getList();

boot-service/src/main/java/com/xwbing/demo/demo.java

@@ -1,5 +1,8 @@
 package com.xwbing.demo;
 
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutionException;
 
 /**
@@ -10,6 +13,18 @@ import java.util.concurrent.ExecutionException;
  */
 public class demo {
     public static void main(String[] args) throws ExecutionException, InterruptedException {
-
+        List<Integer> list = new ArrayList<>();
+        for (int i = 0; i < 100; i++) {
+            list.add(i);
+        }
+        List<Integer> finalList = new ArrayList<>();
+        int size = list.size();
+        CompletableFuture[] futures = new CompletableFuture[size];
+        for (int i = 0; i < size; i++) {
+            Integer integer = list.get(i);
+            futures[i] = CompletableFuture.supplyAsync(() -> finalList.add(integer));
+        }
+        CompletableFuture.allOf(futures).join();
+        System.out.println(finalList);
     }
 }