Merge branch 'main' of github.com:chengfpvoid/JavaCourseCodes into main

团子❤️熊二 · 团子❤️熊二 · commit d3ed9cc3f0a3 · 2020-12-21T21:54:22.000+08:00
diff --git a/03concurrency/0301/src/main/java/java0/conc0303/Homework03.java b/03concurrency/0301/src/main/java/java0/conc0303/Homework03.java
@@ -1,39 +1,61 @@
 package java0.conc0303;
 
+import java.util.concurrent.atomic.AtomicReference;
+
 import java.util.concurrent.CountDownLatch;
 
+
 /**
  * 本周作业：（必做）思考有多少种方式，在main函数启动一个新线程或线程池，
  * 异步运行一个方法，拿到这个方法的返回值后，退出主线程？
  * 写出你的方法，越多越好，提交到github。
- *
+ * <p>
  * 一个简单的代码参考：
  */
 public class Homework03 {
-    
-    public static void main(String[] args) {
-        
-        long start=System.currentTimeMillis();
+
+    public static void main(String[] args) throws Exception {
+
+        long start = System.currentTimeMillis();
         // 在这里创建一个线程或线程池，
         // 异步执行 下面方法
-    
-        int result = sum(); //这是得到的返回值
-        
+
+        // CountDownLatch countDownLatch = new CountDownLatch(1);
+        // ExecutorService executorService = Executors.newCachedThreadPool();
+
+        // Future<Integer> future = executorService.submit(() -> sum());
+        // executorService.execute( () -> {
+        //    int result = sum();
+        //     System.out.println("异步计算结果为："+result);
+        //     countDownLatch.countDown();
+        // });
+        // executorService.shutdown();
+        // countDownLatch.await();
+        //int result = CompletableFuture.supplyAsync(()-> sum()).join();
+
+        //int result = sum(); //这是得到的返回值
+        //int result = future.get();
+        AtomicReference<Integer> result = new AtomicReference<>();
+        new Thread(() -> result.set(sum())).start();
+
         // 确保  拿到result 并输出
-        System.out.println("异步计算结果为："+result);
-         
-        System.out.println("使用时间："+ (System.currentTimeMillis()-start) + " ms");
-        
+        while (result.get() == null) {
+
+        }
+        System.out.println("异步计算结果为："+result.get());
+
+        System.out.println("使用时间：" + (System.currentTimeMillis() - start) + " ms");
+
         // 然后退出main线程
     }
-    
+
     private static int sum() {
         return fibo(36);
     }
-    
+
     private static int fibo(int a) {
-        if ( a < 2) 
+        if (a < 2)
             return 1;
-        return fibo(a-1) + fibo(a-2);
+        return fibo(a - 1) + fibo(a - 2);
     }
 }
