SpringBoot实现异步调用的几种方式
作者:mmseoamin日期:2023-12-21

一、使用 CompletableFuture 实现异步任务

CompletableFuture 是 Java 8 新增的一个异步编程工具,它可以方便地实现异步任务。使用 CompletableFuture 需要满足以下条件:

  1. 异步任务的返回值类型必须是 CompletableFuture 类型;

  2. 在异步任务中使用 CompletableFuture.supplyAsync() 或 CompletableFuture.runAsync() 方法来创建异步任务;

  3. 在主线程中使用 CompletableFuture.get() 方法获取异步任务的返回结果。

我们创建一个服务类,里面包含了异步方法和普通方法。

import org.springframework.stereotype.Service;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.TimeUnit;
/**
 * @author qinxun
 * @date 2023-06-07
 * @Descripion: 异步服务类
 */
@Service
public class AsyncService {
    /**
     * 普通任务操作1
     */
    public String task1() throws InterruptedException {
        TimeUnit.SECONDS.sleep(3);
        return "任务执行完成1";
    }
    /**
     * 普通任务操作2
     */
    public String task2() throws InterruptedException {
        TimeUnit.SECONDS.sleep(2);
        return "任务执行完成2";
    }
    /**
     * 普通任务操作3
     */
    public String task3() throws InterruptedException {
        TimeUnit.SECONDS.sleep(3);
        return "任务执行完成3";
    }
    /**
     * 异步操作1
     */
    public CompletableFuture asyncTask1() {
        return CompletableFuture.supplyAsync(() -> {
            try {
                TimeUnit.SECONDS.sleep(3);
            } catch (InterruptedException e) {
                throw new RuntimeException(e);
            }
            return "异步任务执行完成1";
        });
    }
    /**
     * 异步操作2
     */
    public CompletableFuture asyncTask2() {
        return CompletableFuture.supplyAsync(() -> {
            try {
                TimeUnit.SECONDS.sleep(2);
            } catch (InterruptedException e) {
                throw new RuntimeException(e);
            }
            return "异步任务执行完成2";
        });
    }
    /**
     * 异步操作3
     */
    public CompletableFuture asyncTask3() {
        return CompletableFuture.supplyAsync(() -> {
            try {
                TimeUnit.SECONDS.sleep(3);
            } catch (InterruptedException e) {
                throw new RuntimeException(e);
            }
            return "异步任务执行完成3";
        });
    }
}

我们先测试普通方法的情况,看看最后耗时

import cn.hutool.core.date.StopWatch;
import com.example.quartzdemo.service.AsyncService;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
/**
 * @author qinxun
 * @date 2023-06-07
 * @Descripion: 异步处理测试
 */
@SpringBootTest
public class AsyncTest {
    @Autowired
    private AsyncService asyncService;
    @Test
    void test1() throws InterruptedException {
        StopWatch stopWatch = new StopWatch();
        stopWatch.start();
        // 异步操作
       /* CompletableFuture completableFuture1 = asyncService.asyncTask1();
        CompletableFuture completableFuture2 = asyncService.asyncTask2();
        CompletableFuture completableFuture3 = asyncService.asyncTask3();
        System.out.println(completableFuture1.get());
        System.out.println(completableFuture2.get());
        System.out.println(completableFuture3.get());*/
        // 同步操作
        System.out.println(asyncService.task1());
        System.out.println(asyncService.task2());
        System.out.println(asyncService.task3());
        stopWatch.stop();
        System.out.println("耗时:" + stopWatch.getTotalTimeMillis());
    }
}

程序执行的结果:

任务执行完成1
任务执行完成2
任务执行完成3
耗时:8008

我们可以发现,普通同步方法是按顺序一个个操作的,各个方法不会同时处理。下面我们把这些操作换成异步的方法测试。

import cn.hutool.core.date.StopWatch;
import com.example.quartzdemo.service.AsyncService;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutionException;
/**
 * @author qinxun
 * @date 2023-06-07
 * @Descripion: 异步处理测试
 */
@SpringBootTest
public class AsyncTest {
    @Autowired
    private AsyncService asyncService;
    @Test
    void test1() throws InterruptedException, ExecutionException {
        StopWatch stopWatch = new StopWatch();
        stopWatch.start();
        // 异步操作
        CompletableFuture completableFuture1 = asyncService.asyncTask1();
        CompletableFuture completableFuture2 = asyncService.asyncTask2();
        CompletableFuture completableFuture3 = asyncService.asyncTask3();
        System.out.println(completableFuture1.get());
        System.out.println(completableFuture2.get());
        System.out.println(completableFuture3.get());
        // 同步操作
        /*System.out.println(asyncService.task1());
        System.out.println(asyncService.task2());
        System.out.println(asyncService.task3());*/
        stopWatch.stop();
        System.out.println("耗时:" + stopWatch.getTotalTimeMillis());
    }
}

程序执行结果:

异步任务执行完成1
异步任务执行完成2
异步任务执行完成3
耗时:3008

发现几个方法是异步同时进行的,没有先后的顺序,大大提高了程序执行效率。

二、基于注解 @Async实现异步任务

@Async 注解是 Spring 提供的一种轻量级异步方法实现方式,它可以标记在方法上,用来告诉 Spring 这个方法是一个异步方法,Spring 会将这个方法的执行放在异步线程中进行。使用 @Async 注解需要满足以下条件:

  1. 需要在 Spring Boot 主类上添加 @EnableAsync 注解启用异步功能;

  2. 需要在异步方法上添加 @Async 注解。

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.scheduling.annotation.EnableAsync;
@SpringBootApplication
// 主类上加上这个注解,开启异步功能
@EnableAsync
public class QuartzDemoApplication {
    public static void main(String[] args) {
        SpringApplication.run(QuartzDemoApplication.class, args);
    }
}

修改测试的服务层

import org.springframework.scheduling.annotation.Async;
import org.springframework.scheduling.annotation.AsyncResult;
import org.springframework.stereotype.Service;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
/**
 * @author qinxun
 * @date 2023-06-07
 * @Descripion: 异步服务类
 */
@Service
public class AsyncService {
    /**
     * 同步任务操作1
     */
    public String task1() throws InterruptedException {
        TimeUnit.SECONDS.sleep(3);
        return "任务执行完成1";
    }
    /**
     * 同步任务操作2
     */
    public String task2() throws InterruptedException {
        TimeUnit.SECONDS.sleep(2);
        return "任务执行完成2";
    }
    /**
     * 同步任务操作3
     */
    public String task3() throws InterruptedException {
        TimeUnit.SECONDS.sleep(3);
        return "任务执行完成3";
    }
    /**
     * 异步操作1
     */
    @Async
    public Future asyncTask1() throws InterruptedException {
        long currentTimeMillis = System.currentTimeMillis();
        TimeUnit.SECONDS.sleep(3);
        long currentTimeMillis1 = System.currentTimeMillis();
        System.out.println("task1任务耗时:" + (currentTimeMillis1 - currentTimeMillis) + "ms");
        return new AsyncResult<>("task1完成");
    }
    /**
     * 异步操作2
     */
    @Async
    public Future asyncTask2() throws InterruptedException {
        long currentTimeMillis = System.currentTimeMillis();
        TimeUnit.SECONDS.sleep(2);
        long currentTimeMillis1 = System.currentTimeMillis();
        System.out.println("task1任务耗时:" + (currentTimeMillis1 - currentTimeMillis) + "ms");
        return new AsyncResult<>("task2完成");
    }
    /**
     * 异步操作3
     */
    @Async
    public Future asyncTask3() throws InterruptedException {
        long currentTimeMillis = System.currentTimeMillis();
        TimeUnit.SECONDS.sleep(3);
        long currentTimeMillis1 = System.currentTimeMillis();
        System.out.println("task1任务耗时:" + (currentTimeMillis1 - currentTimeMillis) + "ms");
        return new AsyncResult<>("task3完成");
    }
}

创建一个测试类

import com.example.quartzdemo.service.AsyncService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
/**
 * @author qinxun
 * @date 2023-06-07
 * @Descripion:
 */
@RestController
public class AsyncController {
    @Autowired
    private AsyncService asyncService;
    /**
     * 测试异步
     */
    @RequestMapping("/async")
    public String testAsync() throws InterruptedException, ExecutionException {
        long currentTimeMillis = System.currentTimeMillis();
        Future task1 = asyncService.asyncTask1();
        Future task2 = asyncService.asyncTask2();
        Future task3 = asyncService.asyncTask3();
        while (true) {
            if (task1.isDone() && task2.isDone() && task3.isDone()) {
                // 三个任务都调用完成,退出循环等待
                break;
            }
        }
        System.out.println(task1.get());
        System.out.println(task2.get());
        System.out.println(task3.get());
        long currentTimeMillis1 = System.currentTimeMillis();
        return "task任务总耗时:" + (currentTimeMillis1 - currentTimeMillis) + "ms";
    }
}

执行测试方法

task1任务耗时:2006ms
task1任务耗时:3011ms
task1任务耗时:3011ms
task1完成
task2完成
task3完成

SpringBoot实现异步调用的几种方式,第1张

三、使用 TaskExecutor 实现异步任务

TaskExecutor 是 Spring 提供的一个接口,它定义了一个方法 execute(),用来执行异步任务。使用 TaskExecutor 需要满足以下条件:

  1. 需要在 Spring 配置文件中配置一个 TaskExecutor 实例;

  2. 在异步方法中调用 TaskExecutor 实例的 execute() 方法来执行异步任务。

创建一个异步配置类

import org.springframework.aop.interceptor.AsyncUncaughtExceptionHandler;
import org.springframework.aop.interceptor.SimpleAsyncUncaughtExceptionHandler;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.task.TaskExecutor;
import org.springframework.scheduling.annotation.AsyncConfigurer;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
import java.util.concurrent.Executor;
/**
 * @author qinxun
 * @date 2023-06-07
 * @Descripion: 异步处理配置类
 */
@Configuration
public class AsyncConfig implements AsyncConfigurer {
    @Bean(name = "asyncExecutor")
    public TaskExecutor asyncExecutor() {
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        executor.setCorePoolSize(10);
        executor.setMaxPoolSize(20);
        executor.setQueueCapacity(100);
        executor.setThreadNamePrefix("async-");
        executor.initialize();
        return executor;
    }
    @Override
    public Executor getAsyncExecutor() {
        return asyncExecutor();
    }
    @Override
    public AsyncUncaughtExceptionHandler getAsyncUncaughtExceptionHandler() {
        return new SimpleAsyncUncaughtExceptionHandler();
    }
}

修改下服务类,我们使用自定义的异步配置

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.core.task.TaskExecutor;
import org.springframework.scheduling.annotation.Async;
import org.springframework.stereotype.Service;
import java.util.concurrent.TimeUnit;
/**
 * @author qinxun
 * @date 2023-06-07
 * @Descripion: 异步服务类
 */
@Service
public class AsyncService {
    @Autowired
    @Qualifier("asyncExecutor")
    private TaskExecutor taskExecutor;
    /**
     * 同步任务操作1
     */
    public String task1() throws InterruptedException {
        TimeUnit.SECONDS.sleep(3);
        return "任务执行完成1";
    }
    /**
     * 同步任务操作2
     */
    public String task2() throws InterruptedException {
        TimeUnit.SECONDS.sleep(2);
        return "任务执行完成2";
    }
    /**
     * 同步任务操作3
     */
    public String task3() throws InterruptedException {
        TimeUnit.SECONDS.sleep(3);
        return "任务执行完成3";
    }
    /**
     * 异步操作1
     */
    @Async
    public void asyncTask1() {
        taskExecutor.execute(() -> {
            try {
                TimeUnit.SECONDS.sleep(3);
            } catch (InterruptedException e) {
                throw new RuntimeException(e);
            }
        });
        System.out.println("异步任务执行完成1");
    }
    /**
     * 异步操作2
     */
    @Async
    public void asyncTask2() throws InterruptedException {
        taskExecutor.execute(() -> {
            try {
                TimeUnit.SECONDS.sleep(2);
            } catch (InterruptedException e) {
                throw new RuntimeException(e);
            }
        });
        System.out.println("异步任务执行完成2");
    }
    /**
     * 异步操作3
     */
    @Async
    public void asyncTask3() throws InterruptedException {
        taskExecutor.execute(() -> {
            try {
                TimeUnit.SECONDS.sleep(3);
            } catch (InterruptedException e) {
                throw new RuntimeException(e);
            }
        });
        System.out.println("异步任务执行完成3");
    }
    
}

测试类进行测试

/**
 * @author qinxun
 * @date 2023-06-07
 * @Descripion: 异步处理测试
 */
@SpringBootTest
public class AsyncTest {
    
    @Autowired
    @Qualifier("asyncExecutor")
    private TaskExecutor taskExecutor;
    @Test
    void test1() {
        StopWatch stopWatch = new StopWatch();
        stopWatch.start();
        // 异步操作
       /* asyncService.asyncTask1();
        asyncService.asyncTask2();
        asyncService.asyncTask3();*/
        taskExecutor.execute(() -> System.out.println("异步任务"));
        // 同步操作
        /*System.out.println(asyncService.task1());
        System.out.println(asyncService.task2());
        System.out.println(asyncService.task3());*/
        stopWatch.stop();
        System.out.println("耗时:" + stopWatch.getTotalTimeMillis());
    }
}
耗时:6
异步任务执行完成3
异步任务执行完成1
异步任务执行完成2