Java 实现异步请求方式四：线程池+DeferredResult方式

末蓝、 2023-06-25 03:23 13阅读 0赞

### 1、线程池保持队列+DeferredResult配置结果信息与委托事件 ###

>     private ExecutorService threadPool = Executors.newFixedThreadPool(10);
>     
>     DeferredResult<String>

### 2、代码示例 ###

package com.listen.demo.ctr;
    
    import lombok.extern.slf4j.Slf4j;
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.ResponseBody;
    import org.springframework.web.context.request.async.DeferredResult;
    
    import java.util.concurrent.ExecutorService;
    import java.util.concurrent.Executors;
    import java.util.concurrent.TimeUnit;
    
    import static org.springframework.web.bind.annotation.RequestMethod.GET;
    
    /**
     * @author liuxd
     * @version 1.0
     * @date 2019-12-25 11:36
     */
    @Controller
    @RequestMapping("/api")
    @Slf4j
    public class IVController {
    
        private ExecutorService threadPool = Executors.newFixedThreadPool(10);
    
        @RequestMapping(value = "/req4", method = GET)
        @ResponseBody
        public DeferredResult<String> req4() {
            log.info("主线程名称：" + Thread.currentThread().getName());
    
            //设置超时时间20秒
            DeferredResult<String> deferredResult = new DeferredResult<String>(20000L);
    
            deferredResult.onTimeout(new Runnable() {
                @Override
                public void run() {
                    log.error("异步请求超时");
                    deferredResult.setResult("异步请求超时");
                }
            });
            deferredResult.onCompletion(new Runnable() {
                @Override
                public void run() {
                    log.info("异步调用结束");
                }
            });
    
            threadPool.execute(new Runnable() {
                @Override
                public void run() {
                    log.info("新线程名称：" + Thread.currentThread().getName());
                    try {
                        TimeUnit.SECONDS.sleep(2);
                    } catch (Exception e) {
                        log.error("异步线程发生异常");
                        e.printStackTrace();
                    }
                    deferredResult.setResult("异步请求返回信息");
                }
            });
    
            return deferredResult;
        }
    }