异步处理方式探索

怼烎@ 2022-10-17 04:24 225阅读 0赞

### 这里写自定义目录标题 ###

*  最佳异步处理方式探索
 *   *  CompletableFuture
     *  ThreadPoolTaskExecutor
     *  JDK8并行流处理

# 最佳异步处理方式探索 #

JDK提供了多种异步处理方式，其中归结出来分为两大类。

>  *  java.lang.Runnable 通过 run()方法新建一个线程处理任务，无返回值
>  *  java.util.concurrent.Callable 通过call()方法新建线程处理任务，可以获取返回值

适用两种场景：

1.  不需要获取子线程返回值
2.  需要获取子线程返回值

> 以下是公共依赖

package priv.utirx.explore8.controller;
    
    import cn.hutool.core.date.DateUtil;
    import cn.hutool.core.date.StopWatch;
    import com.google.common.collect.Lists;
    import lombok.SneakyThrows;
    import lombok.extern.slf4j.Slf4j;
    import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    import priv.utirx.explore8.feature.api.R;
    import priv.utirx.explore8.utils.AsyncUtil;
    
    import javax.annotation.Resource;
    import java.util.List;
    import java.util.concurrent.*;

**重要提示： 在获取子线程的执行结果时，务必不要马上获取子线程执行结果。详情请看下面处理方式**

## CompletableFuture ##

@Resource
        private ThreadPoolTaskExecutor taskExecutor;
    
        @SneakyThrows
        @GetMapping("/completableFuture")
        public R<String> completableFuture() { 
            log.info("主线程id: {}, 主线程名称: {}", Thread.currentThread().getId(), Thread.currentThread().getName());
            StopWatch stopWatch = DateUtil.createStopWatch();
            stopWatch.start();
    
            List<String> list = Lists.newArrayListWithExpectedSize(10);
            List<CompletableFuture<String>> futureList = Lists.newArrayListWithExpectedSize(10);
            for (int i = 0; i < 10; i++) { 
                // 异步开启, 子线程执行任务, 因为get()方法是阻塞的，所以主线程一直在等待子线程的返回, 如果此时获取结果，总耗时在20158 毫秒
                // String message = CompletableFuture.supplyAsync(() -> testException(false))
                // .exceptionally(Throwable::getMessage).get();
                // list.add(message);
    
                CompletableFuture<String> exceptionally = CompletableFuture.supplyAsync(() -> testException(false))
                        .exceptionally(Throwable::getMessage);
                futureList.add(exceptionally);
            }
    
            for (CompletableFuture<String> future : futureList) { 
                String str = future.get();
                list.add(str);
            }
    
            list.forEach(System.out::println);
            stopWatch.stop();
            log.info("执行完成，总用时: {} 毫秒", stopWatch.getTotalTimeMillis());
            return R.ok("完成");
        }
    
        @SneakyThrows
        private String testException(boolean is) { 
            log.info("子线程id: {}, 子线程名称: {}", Thread.currentThread().getId(), Thread.currentThread().getName());
            TimeUnit.SECONDS.sleep(1);
            if (is) { 
                throw new RuntimeException("账户金额异常");
            }
            TimeUnit.SECONDS.sleep(1);
            return "处理成功";
        }

运行结果：

2021-06-01 17:58:08.934  INFO 20912 --- [nio-8989-exec-2] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring DispatcherServlet 'dispatcherServlet'
    2021-06-01 17:58:08.935  INFO 20912 --- [nio-8989-exec-2] o.s.web.servlet.DispatcherServlet        : Initializing Servlet 'dispatcherServlet'
    2021-06-01 17:58:08.935  INFO 20912 --- [nio-8989-exec-2] o.s.web.servlet.DispatcherServlet        : Completed initialization in 0 ms
    2021-06-01 17:58:08.957  INFO 20912 --- [nio-8989-exec-2] p.u.explore8.controller.AsyncController  : 主线程id: 39, 主线程名称: http-nio-8989-exec-2
    2021-06-01 17:58:08.966  INFO 20912 --- [onPool-worker-9] p.u.explore8.controller.AsyncController  : 子线程id: 56, 子线程名称: ForkJoinPool.commonPool-worker-9
    2021-06-01 17:58:08.966  INFO 20912 --- [onPool-worker-2] p.u.explore8.controller.AsyncController  : 子线程id: 57, 子线程名称: ForkJoinPool.commonPool-worker-2
    2021-06-01 17:58:08.966  INFO 20912 --- [nPool-worker-11] p.u.explore8.controller.AsyncController  : 子线程id: 58, 子线程名称: ForkJoinPool.commonPool-worker-11
    2021-06-01 17:58:08.966  INFO 20912 --- [onPool-worker-4] p.u.explore8.controller.AsyncController  : 子线程id: 59, 子线程名称: ForkJoinPool.commonPool-worker-4
    2021-06-01 17:58:08.967  INFO 20912 --- [onPool-worker-6] p.u.explore8.controller.AsyncController  : 子线程id: 61, 子线程名称: ForkJoinPool.commonPool-worker-6
    2021-06-01 17:58:08.967  INFO 20912 --- [nPool-worker-13] p.u.explore8.controller.AsyncController  : 子线程id: 60, 子线程名称: ForkJoinPool.commonPool-worker-13
    2021-06-01 17:58:08.967  INFO 20912 --- [onPool-worker-8] p.u.explore8.controller.AsyncController  : 子线程id: 63, 子线程名称: ForkJoinPool.commonPool-worker-8
    2021-06-01 17:58:08.967  INFO 20912 --- [nPool-worker-15] p.u.explore8.controller.AsyncController  : 子线程id: 62, 子线程名称: ForkJoinPool.commonPool-worker-15
    2021-06-01 17:58:08.967  INFO 20912 --- [onPool-worker-1] p.u.explore8.controller.AsyncController  : 子线程id: 64, 子线程名称: ForkJoinPool.commonPool-worker-1
    2021-06-01 17:58:08.967  INFO 20912 --- [nPool-worker-10] p.u.explore8.controller.AsyncController  : 子线程id: 65, 子线程名称: ForkJoinPool.commonPool-worker-10
    处理成功
    处理成功
    处理成功
    处理成功
    处理成功
    处理成功
    处理成功
    处理成功
    处理成功
    处理成功
    2021-06-01 17:58:10.993  INFO 20912 --- [nio-8989-exec-2] p.u.explore8.controller.AsyncController  : 执行完成，总用时: 2032 毫秒

## ThreadPoolTaskExecutor ##

线程池配置请查看另一篇文章： [线程池配置][Link 1]

@Resource
        private ThreadPoolTaskExecutor taskExecutor;
        
      	@GetMapping("/getResult")
        public R<String> getAsyncResult() { 
            StopWatch stopWatch = DateUtil.createStopWatch();
            stopWatch.start();
    
            List<String> list = Lists.newArrayListWithExpectedSize(10);
            List<Future<String>> submitList = Lists.newArrayListWithExpectedSize(10);
            for (int i = 0; i < 10; i++) { 
                log.info("循环遍历, 线程ID: [{}], 线程名称: [{}], 执行批次: ", Thread.currentThread().getId(), Thread.currentThread()
                        .getName());
                // 关键点，开启一个子线程执行任务，而不是同步获取结果，等待执行完成之后再for循环获取
                Future<String> submit = taskExecutor.submit(() -> asyncUtil.pay());
                submitList.add(submit);
            }
    
            for (Future<String> future : submitList) { 
                try { 
                    list.add(future.get());
                } catch (InterruptedException e) { 
                    e.printStackTrace();
                } catch (ExecutionException e) { 
                    e.printStackTrace();
                }
            }
    
            list.forEach(System.out::println);
            stopWatch.stop();
            log.info("执行完成，总用时: {} 毫秒", stopWatch.getTotalTimeMillis());
            return R.ok();
        }

执行结果：

2021-06-01 17:58:39.814  INFO 20912 --- [nio-8989-exec-1] p.u.explore8.controller.AsyncController  : 循环遍历, 线程ID: [38], 线程名称: [http-nio-8989-exec-1], 执行批次: 
    2021-06-01 17:58:39.815  INFO 20912 --- [nio-8989-exec-1] p.u.explore8.controller.AsyncController  : 循环遍历, 线程ID: [38], 线程名称: [http-nio-8989-exec-1], 执行批次: 
    2021-06-01 17:58:39.815  INFO 20912 --- [nio-8989-exec-1] p.u.explore8.controller.AsyncController  : 循环遍历, 线程ID: [38], 线程名称: [http-nio-8989-exec-1], 执行批次: 
    2021-06-01 17:58:39.815  INFO 20912 --- [  self-worker-0] priv.utirx.explore8.utils.AsyncUtil      : 子线程ID: [67], 子线程名称: [self-worker-0] 进入异步执行方法 pay
    2021-06-01 17:58:39.815  INFO 20912 --- [nio-8989-exec-1] p.u.explore8.controller.AsyncController  : 循环遍历, 线程ID: [38], 线程名称: [http-nio-8989-exec-1], 执行批次: 
    2021-06-01 17:58:39.815  INFO 20912 --- [  self-worker-1] priv.utirx.explore8.utils.AsyncUtil      : 子线程ID: [68], 子线程名称: [self-worker-1] 进入异步执行方法 pay
    2021-06-01 17:58:39.815  INFO 20912 --- [nio-8989-exec-1] p.u.explore8.controller.AsyncController  : 循环遍历, 线程ID: [38], 线程名称: [http-nio-8989-exec-1], 执行批次: 
    2021-06-01 17:58:39.815  INFO 20912 --- [  self-worker-3] priv.utirx.explore8.utils.AsyncUtil      : 子线程ID: [70], 子线程名称: [self-worker-3] 进入异步执行方法 pay
    2021-06-01 17:58:39.815  INFO 20912 --- [nio-8989-exec-1] p.u.explore8.controller.AsyncController  : 循环遍历, 线程ID: [38], 线程名称: [http-nio-8989-exec-1], 执行批次: 
    2021-06-01 17:58:39.815  INFO 20912 --- [  self-worker-2] priv.utirx.explore8.utils.AsyncUtil      : 子线程ID: [69], 子线程名称: [self-worker-2] 进入异步执行方法 pay
    2021-06-01 17:58:39.816  INFO 20912 --- [nio-8989-exec-1] p.u.explore8.controller.AsyncController  : 循环遍历, 线程ID: [38], 线程名称: [http-nio-8989-exec-1], 执行批次: 
    2021-06-01 17:58:39.816  INFO 20912 --- [  self-worker-4] priv.utirx.explore8.utils.AsyncUtil      : 子线程ID: [71], 子线程名称: [self-worker-4] 进入异步执行方法 pay
    2021-06-01 17:58:39.816  INFO 20912 --- [  self-worker-5] priv.utirx.explore8.utils.AsyncUtil      : 子线程ID: [72], 子线程名称: [self-worker-5] 进入异步执行方法 pay
    2021-06-01 17:58:39.816  INFO 20912 --- [nio-8989-exec-1] p.u.explore8.controller.AsyncController  : 循环遍历, 线程ID: [38], 线程名称: [http-nio-8989-exec-1], 执行批次: 
    2021-06-01 17:58:39.816  INFO 20912 --- [nio-8989-exec-1] p.u.explore8.controller.AsyncController  : 循环遍历, 线程ID: [38], 线程名称: [http-nio-8989-exec-1], 执行批次: 
    2021-06-01 17:58:39.816  INFO 20912 --- [  self-worker-6] priv.utirx.explore8.utils.AsyncUtil      : 子线程ID: [73], 子线程名称: [self-worker-6] 进入异步执行方法 pay
    2021-06-01 17:58:39.816  INFO 20912 --- [nio-8989-exec-1] p.u.explore8.controller.AsyncController  : 循环遍历, 线程ID: [38], 线程名称: [http-nio-8989-exec-1], 执行批次: 
    2021-06-01 17:58:39.816  INFO 20912 --- [  self-worker-7] priv.utirx.explore8.utils.AsyncUtil      : 子线程ID: [74], 子线程名称: [self-worker-7] 进入异步执行方法 pay
    2021-06-01 17:58:39.817  INFO 20912 --- [  self-worker-9] priv.utirx.explore8.utils.AsyncUtil      : 子线程ID: [76], 子线程名称: [self-worker-9] 进入异步执行方法 pay
    2021-06-01 17:58:39.817  INFO 20912 --- [  self-worker-8] priv.utirx.explore8.utils.AsyncUtil      : 子线程ID: [75], 子线程名称: [self-worker-8] 进入异步执行方法 pay
    成功
    成功
    成功
    成功
    成功
    成功
    成功
    成功
    成功
    成功
    2021-06-01 17:58:40.828  INFO 20912 --- [nio-8989-exec-1] p.u.explore8.controller.AsyncController  : 执行完成，总用时: 1013 毫秒

## JDK8并行流处理 ##

请查看我的另一篇文章： [并发编程][Link 2]

（本文完！引用内容务必附原文连接！）

[Link 1]: https://blog.csdn.net/suolongdse/article/details/115524595?spm=1001.2014.3001.5501
[Link 2]: https://blog.csdn.net/suolongdse/article/details/109890059?spm=1001.2014.3001.5501