多任务

Author: enjoyCoding666

src/main/java/com/java8/completefuture/CompleteFutureDemo.java

@@ -24,12 +24,8 @@ public static void supplyAsyncGet()  {
         try {
             //获取返回值，2秒超时
             result = completableFuture.get(2, TimeUnit.SECONDS);
-        } catch (InterruptedException e) {
-            logger.error("InterruptedException error.", e);
-        } catch (ExecutionException e) {
-            logger.error("ExecutionException error.", e);
-        } catch (TimeoutException e) {
-            logger.error("TimeoutException error.", e);
+        } catch (Exception e) {
+            logger.error("completableFuture.get error.", e);
         }
         logger.info("result:"+result);
     }

src/main/java/com/java8/completefuture/OfAllGetDemo.java

@@ -23,28 +23,27 @@ public static void main(String[] args) {
     public static void allOfGet()  {
         //该线程池仅用于示例，实际建议使用自定义的线程池
         ExecutorService executorService = Executors.newCachedThreadPool();
-        String word1 = "word1";
-        String word2 = "word2";
 
         //线程安全的list，适合写多读少的场景
-        List<String> strList = Collections.synchronizedList(new ArrayList<>(50));
+        List<String> resultList = Collections.synchronizedList(new ArrayList<>(50));
         CompletableFuture<String> completableFuture1 = CompletableFuture.supplyAsync(
-                () -> getResult(word1, 1000), executorService)
+                () -> runTask("result1", 1000), executorService)
                 .whenComplete((result, throwable) -> {
-                    //任务完成时执行
+                    //任务完成时执行。用list存放任务的返回值
                     if (result != null) {
-                        strList.add(result);
+                        resultList.add(result);
                     }
+                    //触发异常
                     if (throwable != null) {
                         logger.error("completableFuture1  error:{}", throwable);
                     }
                 });
 
         CompletableFuture<String> completableFuture2 = CompletableFuture.supplyAsync(
-                () -> getResult(word2, 1500), executorService)
+                () -> runTask("result2", 1500), executorService)
                 .whenComplete((result, throwable) ->{
                     if (result != null) {
-                        strList.add(result);
+                        resultList.add(result);
                     }
                     if (throwable != null) {
                         logger.error("completableFuture2  error:{}", throwable);
@@ -57,27 +56,29 @@ public static void allOfGet()  {
         futureList.add(completableFuture2);
 
         try  {
-            //多个任务，耗时不超时2秒
-            CompletableFuture.allOf(futureList.toArray(new CompletableFuture[0]))
-                    .get(2, TimeUnit.SECONDS);
-        } catch (InterruptedException | ExecutionException e) {
-            logger.error("CompletableFuture.allOf InterruptedException error.", e);
-        } catch (TimeoutException e) {
-            logger.error("CompletableFuture.allOf TimeoutException error.", e);
+            //多个任务
+            CompletableFuture[] futureArray = futureList.toArray(new CompletableFuture[0]);
+            //将多个任务，汇总成一个任务，总共耗时不超时2秒
+            CompletableFuture.allOf(futureArray).get(2, TimeUnit.SECONDS);
+        } catch (Exception e) {
+            logger.error("CompletableFuture.allOf Exception error.", e);
         }
-        List<String> resultList = new ArrayList<>(strList);
+        List<String> list = new ArrayList<>(resultList);
 
-        resultList.forEach(System.out::println);
+        list.forEach(System.out::println);
     }
 
 
-    private static String getResult(String result, int millis) {
+    private static String runTask(String result, int millis) {
         try {
+            //此处忽略实际的逻辑，用sleep代替
             //任务耗时。可以分别设置1000和3000，看未超时和超时的不同结果。
             Thread.sleep(millis);
         } catch (InterruptedException e) {
             logger.error("supplyAsyncGet error.");
         }
         return result;
     }
+
+
 }

src/main/java/com/thread/threadpool/SubmitDemo.java

@@ -0,0 +1,46 @@
+package com.thread.threadpool;
+
+import lombok.extern.slf4j.Slf4j;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.*;
+
+@Slf4j
+public class SubmitDemo {
+    public static void main(String[] args)  {
+        submit();
+    }
+
+    public static void submit()  {
+        long start = System.currentTimeMillis();
+        //该线程池仅用于示例，实际建议使用自定义的线程池
+        ExecutorService executor = Executors.newCachedThreadPool();
+        Future<String> future1 = executor.submit(() -> {
+            Thread.sleep(4000);
+            return "task1";
+        });
+        Future<String> future2 = executor.submit(() -> {
+            Thread.sleep(5000);
+            return "task2";
+        });
+
+        List<String> resultList = new ArrayList<>();
+        addFutureResult(future1, resultList, 2,"add result1 error.");
+
+        addFutureResult(future2, resultList,  2, "add result2 error.");
+
+        System.out.println("it cost time :"+ (System.currentTimeMillis()-start) );
+        resultList.forEach(System.out::println);
+    }
+
+    private static void addFutureResult(Future<String> future, List<String> resultList, int timeout, String s) {
+        try {
+            String result = future.get(timeout, TimeUnit.SECONDS);
+            resultList.add(result);
+        } catch (Exception e) {
+            log.error(s, e);
+        }
+    }
+
+}