Java实现异步处理HTTP请求_方式二：通过DeferredResult

女爷i 2023-07-21 11:08 58阅读 0赞

### 1、DeferredResult ###

spring 支持http异步返回

### 2、异步处理 ###

开启新线程，处理数据并赋值返回。

### 3、代码示例 ###

**1）controller**

package com.liuxd.controller;
    
    import com.liuxd.entity.Responses;
    import com.liuxd.service.TaskService2;
    import lombok.extern.slf4j.Slf4j;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RestController;
    import org.springframework.web.context.request.async.DeferredResult;
    
    @Slf4j
    @RestController
    public class AsyncCtr2 {
    
        @Autowired
        private TaskService2 taskService2;
    
        @GetMapping(value = "/getResult")
        public DeferredResult<Responses<String>> getResult() {
            log.info("收到HTTP请求...");
            long startTime = System.currentTimeMillis();
    
            DeferredResult<Responses<String>> deferredResult = new DeferredResult<Responses<String>>();
    
            new Thread(new Runnable() {
                @Override
                public void run() {
                    taskService2.getData(deferredResult);
                }
            }).start();
    
            log.info("接收HTTP请求线程任务已完成,退出!");
            long endTime = System.currentTimeMillis();
            log.info("http请求总耗时： " + (endTime - startTime) + "ms");
    
            return deferredResult;
    
        }
    }

**2）service**

package com.liuxd.service;
    
    import com.liuxd.entity.Responses;
    import lombok.extern.slf4j.Slf4j;
    import org.springframework.stereotype.Service;
    import org.springframework.web.context.request.async.DeferredResult;
    
    @Slf4j
    @Service
    public class TaskService2 {
    
        public void getData(DeferredResult<Responses<String>> deferredResult) {
    
            log.info("调用service异步有返回方法，开始执行...");
            long startTime = System.currentTimeMillis();
    
            try {
                Thread.sleep(2500L);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
    
            log.info("调用service异步有返回方法，执行结束！！");
    
            long endTime = System.currentTimeMillis();
            log.info("调用service异步有返回方法总耗时： " + (endTime - startTime) + "ms");
    
            deferredResult.setResult(new Responses<>(0, "异步处理完成", "SUCCESS"));
    
        }
    
    
    }

**3）Responses**

package com.liuxd.entity;
    
    import lombok.AllArgsConstructor;
    import lombok.Builder;
    import lombok.Data;
    import lombok.NoArgsConstructor;
    
    @Data
    @Builder
    @NoArgsConstructor
    @AllArgsConstructor
    public class Responses<T> {
    
        private Integer code;
    
        private String msg;
    
        private T data;
    
    }

**4）打印结果**

![20200403151817127.png][]

**5）结果分析**

1）http主线程接受请求，处理完请求后线程结束

2）异步线程结束后，返回

[20200403151817127.png]: /images/20230528/5f9123a4e40e477db9653c6e3b7e1e90.png