Spring?異步接口返回結(jié)果的四種方式

更新時間：2022年08月28日 16:52:27 作者：魚找水需要時間

這篇文章主要介紹了Spring?異步接口返回結(jié)果的四種方式，文章圍繞主題展開詳細的內(nèi)容介紹，具有一定的參考價值，感興趣的小伙伴可以參考一下

1. 需求

開發(fā)中我們經(jīng)常遇到異步接口需要執(zhí)行一些耗時的操作，并且接口要有返回結(jié)果。

使用場景：用戶綁定郵箱、手機號，將郵箱、手機號保存入庫后發(fā)送郵件或短信通知
接口要求：數(shù)據(jù)入庫后給前臺返回成功通知，后臺異步執(zhí)行發(fā)郵件、短信通知操作

一般的話在企業(yè)中會借用消息隊列來實現(xiàn)發(fā)送，業(yè)務(wù)量大的話有一個統(tǒng)一消費、管理的地方。但有時項目中沒有引用mq相關(guān)組件，這時為了實現(xiàn)一個功能去引用、維護一個消息組件有點大材小用，下面介紹幾種不引用消息隊列情況下的解決方式

定義線程池：

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.task.TaskExecutor;
import org.springframework.scheduling.annotation.EnableAsync;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
import java.util.concurrent.ThreadPoolExecutor;
/**
 * @description: 公共配置
 * @author: yh
 * @date: 2022/8/26
 */
@EnableAsync
@Configuration
public class CommonConfig {
    @Bean
    public TaskExecutor taskExecutor() {
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();

        // 設(shè)置核心線程數(shù)
        executor.setCorePoolSize(50);
        // 設(shè)置最大線程數(shù)
        executor.setMaxPoolSize(200);
        // 設(shè)置隊列容量
        executor.setQueueCapacity(200);
        // 設(shè)置線程活躍時間（秒）
        executor.setKeepAliveSeconds(800);
        // 設(shè)置默認線程名稱
        executor.setThreadNamePrefix("task-");
        // 設(shè)置拒絕策略
        executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
        // 等待所有任務(wù)結(jié)束后再關(guān)閉線程池
        executor.setWaitForTasksToCompleteOnShutdown(true);
        return executor;
    }
}

2. 解決方案

2.1 @Async

定義異步任務(wù)，如發(fā)送郵件、短信等

@Service
public class ExampleServiceImpl implements ExampleService {
    @Async("taskExecutor")
    @Override
    public void sendMail(String email) {
        try {
            Thread.sleep(3000);
            System.out.println("異步任務(wù)執(zhí)行完成, " + email + " 當(dāng)前線程：" + Thread.currentThread().getName());
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        }
    }
}

Controller

@RequestMapping(value = "/api")
@RestController
public class ExampleController {
    @Resource
    private ExampleService exampleService;

    @RequestMapping(value = "/bind",method = RequestMethod.GET)
    public String bind(@RequestParam("email") String email) {
        long startTime = System.currentTimeMillis();
        try {
            // 綁定郵箱....業(yè)務(wù)
            Thread.sleep(2000);
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        }
        //模擬異步任務(wù)(發(fā)郵件通知、短信等)
        exampleService.sendMail(email);

        long endTime = System.currentTimeMillis();
        System.out.println("方法執(zhí)行完成返回，耗時：" + (endTime - startTime));
        return "ok";
    }
}

運行結(jié)果：

2.2 TaskExecutor

@RequestMapping(value = "/api")
@RestController
public class ExampleController {
    @Resource
    private ExampleService exampleService;
    @Resource
    private TaskExecutor taskExecutor;

    @RequestMapping(value = "/bind", method = RequestMethod.GET)
    public String bind(@RequestParam("email") String email) {
        long startTime = System.currentTimeMillis();
        try {
            // 綁定郵箱....業(yè)務(wù)
            Thread.sleep(2000);

            // 將發(fā)送郵件交給線程池去執(zhí)行
            taskExecutor.execute(() -> {
                exampleService.sendMail(email);
            });
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        }

        long endTime = System.currentTimeMillis();
        System.out.println("方法執(zhí)行完成返回，耗時：" + (endTime - startTime));
        return "ok";
    }
}

運行結(jié)果：

2.3 Future

首先去掉Service方法中的@Async("taskExecutor")，此時執(zhí)行就會變成同步，總計需要5s才能完成接口返回。這次我們使用jdk1.8中的CompletableFuture來實現(xiàn)異步任務(wù)

@RequestMapping(value = "/api")
@RestController
public class ExampleController {
    @Resource
    private ExampleService exampleService;
    @Resource
    private TaskExecutor taskExecutor;

    @RequestMapping(value = "/bind", method = RequestMethod.GET)
    public String bind(@RequestParam("email") String email) {
        long startTime = System.currentTimeMillis();
        try {
            // 綁定郵箱....業(yè)務(wù)
            Thread.sleep(2000);

            // 將發(fā)送郵件交給異步任務(wù)Future，需要記錄返回值用supplyAsync
            CompletableFuture.runAsync(() -> {
                exampleService.sendMail(email);
            }, taskExecutor);

        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        }

        long endTime = System.currentTimeMillis();
        System.out.println("方法執(zhí)行完成返回，耗時：" + (endTime - startTime));
        return "ok";
    }
}

運行結(jié)果：

2.4 @EventListener

Spring為我們提供的一個事件監(jiān)聽、訂閱的實現(xiàn)，內(nèi)部實現(xiàn)原理是觀察者設(shè)計模式；為的就是業(yè)務(wù)系統(tǒng)邏輯的解耦,提高可擴展性以及可維護性。事件發(fā)布者并不需要考慮誰去監(jiān)聽，監(jiān)聽具體的實現(xiàn)內(nèi)容是什么，發(fā)布者的工作只是為了發(fā)布事件而已。

2.4.1 定義event事件模型

public class NoticeEvent extends ApplicationEvent {
    private String email;
    private String phone;
    public NoticeEvent(Object source, String email, String phone) {
        super(source);
        this.email = email;
        this.phone = phone;
    }
    public String getEmail() {
        return email;
    }
    public void setEmail(String email) {
        this.email = email;
    }
    public String getPhone() {
        return phone;
    }
    public void setPhone(String phone) {
        this.phone = phone;
    }
}

2.4.2 事件監(jiān)聽

@Component
public class ComplaintEventListener {

    /**
     * 只監(jiān)聽NoticeEvent事件
     * @author: yh
     * @date: 2022/8/27
     */
    @Async
    @EventListener(value = NoticeEvent.class)
//    @Order(1) 指定事件執(zhí)行順序
    public void sendEmail(NoticeEvent noticeEvent) {
        //發(fā)郵件
        try {
            Thread.sleep(3000);
            System.out.println("發(fā)送郵件任務(wù)執(zhí)行完成, " + noticeEvent.getEmail() + " 當(dāng)前線程：" + Thread.currentThread().getName());
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        }
    }

    @Async
    @EventListener(value = NoticeEvent.class)
//    @Order(2) 指定事件執(zhí)行順序
    public void sendMsg(NoticeEvent noticeEvent) {
        //發(fā)短信
        try {
            Thread.sleep(3000);
            System.out.println("發(fā)送短信步任務(wù)執(zhí)行完成, " + noticeEvent.getPhone() + " 當(dāng)前線程：" + Thread.currentThread().getName());
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        }
    }
}

2.4.5 事件發(fā)布

@RequestMapping(value = "/api")
@RestController
public class ExampleController {
    /**
     * 用于事件推送
     * @author:  yh
     * @date:  2022/8/27
     */
    @Autowired
    private ApplicationEventPublisher applicationEventPublisher;

    @RequestMapping(value = "/bind", method = RequestMethod.GET)
    public String bind(@RequestParam("email") String email) {
        long startTime = System.currentTimeMillis();
        try {
            // 綁定郵箱....業(yè)務(wù)
            Thread.sleep(2000);

            // 發(fā)布事件，這里偷個懶手機號寫死
            applicationEventPublisher.publishEvent(new NoticeEvent(this, email, "13211112222"));
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        }
        long endTime = System.currentTimeMillis();
        System.out.println("方法執(zhí)行完成返回，耗時：" + (endTime - startTime));
        return "ok";
    }
}

運行結(jié)果：