SpringBoot多线程进行异步请求的处理方式

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.annotation.EnableAsync;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor; 
import java.util.concurrent.Executor;
 
@Configuration
@EnableAsync  // 启用异步任务
public class AsyncConfig {
 
    // 声明一个线程池(并指定线程池的名字)
    @Bean("AsyncThread")
    public Executor asyncExecutor() {
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        //核心线程数5：线程池创建时候初始化的线程数
        executor.setCorePoolSize(5);
        //最大线程数5：线程池最大的线程数，只有在缓冲队列满了之后才会申请超过核心线程数的线程
        executor.setMaxPoolSize(10);
        //缓冲队列500：用来缓冲执行任务的队列
        executor.setQueueCapacity(500);
        //允许线程的空闲时间60秒：当超过了核心线程出之外的线程在空闲时间到达之后会被销毁
        executor.setKeepAliveSeconds(60);
        //线程池名的前缀：设置好了之后可以方便我们定位处理任务所在的线程池
        executor.setThreadNamePrefix("AsyncThread-");
        executor.initialize();
        return executor;
    }
}

    @Async("AsyncThread")
    @RequestMapping(value = "/addBlog")
    public CompletableFuture<String> addBlog(HttpSession httpSession, Blog blog, String blogId, boolean tempSave) {
        System.out.println("\n\n----------------------------------------------");
        System.out.println(Thread.currentThread().getName() + "正在处理请求");
        System.out.println("----------------------------------------------");
        String result = "请求失败";
        //....你的业务逻辑
        return CompletableFuture.completedFuture(result);
    }

    @RestController
    public class HelloController {undefined     
        private static final Logger logger = LoggerFactory.getLogger(HelloController.class);        
        @Autowired
        private HelloService hello;
     
        @GetMapping("/helloworld")
        public String helloWorldController() {undefined
            return hello.sayHello();
        }
     
        /**
         * 异步调用restful
         * 当controller返回值是Callable的时候，springmvc就会启动一个线程将Callable交给TaskExecutor去处理
         * 然后DispatcherServlet还有所有的spring拦截器都退出主线程，然后把response保持打开的状态
         * 当Callable执行结束之后，springmvc就会重新启动分配一个request请求，然后DispatcherServlet就重新
         * 调用和处理Callable异步执行的返回结果， 然后返回视图
         *
         * @return
         */
        @GetMapping("/hello")
        public Callable<String> helloController() {undefined
            logger.info(Thread.currentThread().getName() + " 进入helloController方法");
            Callable<String> callable = new Callable<String>() {undefined
     
                @Override
                public String call() throws Exception {undefined
                    logger.info(Thread.currentThread().getName() + " 进入call方法");
                    String say = hello.sayHello();
                    logger.info(Thread.currentThread().getName() + " 从helloService方法返回");
                    return say;
                }
            };
            logger.info(Thread.currentThread().getName() + " 从helloController方法返回");
            return callable;
        }
    }

    @RestController
    public class HelloController {undefined     
        private static final Logger logger = LoggerFactory.getLogger(HelloController.class);        
        @Autowired
        private HelloService hello;     
            /**
         * 带超时时间的异步请求 通过WebAsyncTask自定义客户端超时间
         *
         * @return
         */
        @GetMapping("/world")
        public WebAsyncTask<String> worldController() {undefined
            logger.info(Thread.currentThread().getName() + " 进入helloController方法");
     
            // 3s钟没返回，则认为超时
            WebAsyncTask<String> webAsyncTask = new WebAsyncTask<>(3000, new Callable<String>() {undefined
     
                @Override
                public String call() throws Exception {undefined
                    logger.info(Thread.currentThread().getName() + " 进入call方法");
                    String say = hello.sayHello();
                    logger.info(Thread.currentThread().getName() + " 从helloService方法返回");
                    return say;
                }
            });
            logger.info(Thread.currentThread().getName() + " 从helloController方法返回");
     
            webAsyncTask.onCompletion(new Runnable() {undefined
     
                @Override
                public void run() {undefined
                    logger.info(Thread.currentThread().getName() + " 执行完毕");
                }
            });
     
            webAsyncTask.onTimeout(new Callable<String>() {undefined
     
                @Override
                public String call() throws Exception {undefined
                    logger.info(Thread.currentThread().getName() + " onTimeout");
                    // 超时的时候，直接抛异常，让外层统一处理超时异常
                    throw new TimeoutException("调用超时");
                }
            });
            return webAsyncTask;
        }
     
        /**
         * 异步调用，异常处理，详细的处理流程见MyExceptionHandler类
         *
         * @return
         */
        @GetMapping("/exception")
        public WebAsyncTask<String> exceptionController() {undefined
            logger.info(Thread.currentThread().getName() + " 进入helloController方法");
            Callable<String> callable = new Callable<String>() {undefined
     
                @Override
                public String call() throws Exception {undefined
                    logger.info(Thread.currentThread().getName() + " 进入call方法");
                    throw new TimeoutException("调用超时!");
                }
            };
            logger.info(Thread.currentThread().getName() + " 从helloController方法返回");
            return new WebAsyncTask<>(20000, callable);
        }     
    }

    @Component
    public class LongTimeTask {undefined
        private final Logger logger = LoggerFactory.getLogger(this.getClass());
        @Async
        public void execute(DeferredResult<String> deferred){undefined
            logger.info(Thread.currentThread().getName() + "进入 taskService 的 execute方法");
            try {undefined
                // 模拟长时间任务调用，睡眠2s
                TimeUnit.SECONDS.sleep(2);
                // 2s后给Deferred发送成功消息，告诉Deferred，我这边已经处理完了，可以返回给客户端了
                deferred.setResult("world");
            } catch (InterruptedException e) {undefined
                e.printStackTrace();
            }
        }
    }

    @RestController
    public class AsyncDeferredController {undefined
        private final Logger logger = LoggerFactory.getLogger(this.getClass());
        private final LongTimeTask taskService;        
        @Autowired
        public AsyncDeferredController(LongTimeTask taskService) {undefined
            this.taskService = taskService;
        }
        
        @GetMapping("/deferred")
        public DeferredResult<String> executeSlowTask() {undefined
            logger.info(Thread.currentThread().getName() + "进入executeSlowTask方法");
            DeferredResult<String> deferredResult = new DeferredResult<>();
            // 调用长时间执行任务
            taskService.execute(deferredResult);
            // 当长时间任务中使用deferred.setResult("world");这个方法时，会从长时间任务中返回，继续controller里面的流程
            logger.info(Thread.currentThread().getName() + "从executeSlowTask方法返回");
            // 超时的回调方法
            deferredResult.onTimeout(new Runnable(){undefined
            
                @Override
                public void run() {undefined
                    logger.info(Thread.currentThread().getName() + " onTimeout");
                    // 返回超时信息
                    deferredResult.setErrorResult("time out!");
                }
            });
            
            // 处理完成的回调方法，无论是超时还是处理成功，都会进入这个回调方法
            deferredResult.onCompletion(new Runnable(){undefined
            
                @Override
                public void run() {undefined
                    logger.info(Thread.currentThread().getName() + " onCompletion");
                }
            });            
            return deferredResult;
        }
    }

    @Component
    public class MyAsyncHandlerInterceptor implements AsyncHandlerInterceptor {undefined        
        private static final Logger logger = LoggerFactory.getLogger(MyAsyncHandlerInterceptor.class);     
        @Override
        public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
                throws Exception {undefined
            return true;
        }
     
        @Override
        public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,
                ModelAndView modelAndView) throws Exception {undefined
    //        HandlerMethod handlerMethod = (HandlerMethod) handler;
            logger.info(Thread.currentThread().getName()+ "服务调用完成，返回结果给客户端");
        }
     
        @Override
        public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)
                throws Exception {undefined
            if(null != ex){undefined
                System.out.println("发生异常:"+ex.getMessage());
            }
        }
     
        @Override
        public void afterConcurrentHandlingStarted(HttpServletRequest request, HttpServletResponse response, Object handler)
                throws Exception {undefined            
            // 拦截之后，重新写回数据，将原来的hello world换成如下字符串
            String resp = "my name is chhliu!";
            response.setContentLength(resp.length());
            response.getOutputStream().write(resp.getBytes());            
            logger.info(Thread.currentThread().getName() + " 进入afterConcurrentHandlingStarted方法");
        }     
    }