异步进程在 Springboot 应用程序中不起作用 [重复]

Question

我正在我的代码中尝试异步进程。我写了如下代码。但是异步进程不起作用。线程名称“”本身未显示在日志中。看起来服务类不是在寻找 bean 'asyncExecutor'。我在这里缺少什么。

@SpringBootApplication
@EnableAsync
public class  MyMainApplication {

    @Bean(name = "asyncExecutor")
    public Executor asyncExecutor() {
          ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
            executor.setCorePoolSize(3);
            executor.setMaxPoolSize(3);
            executor.setQueueCapacity(100);
            executor.setThreadNamePrefix("AsynchThread-");
            executor.initialize();
            return executor; 
    }
    
    public static void main(String[] args) {
        SpringApplication.run(MyMainApplication.class, args);
    }

}

服务类

public void getSampleDetails(String param1, String param2) {
    log.info("Inside - getSampleDetails");
    CompletableFuture<Map<String, String>> sampleMap1 = null;
    CompletableFuture<Map<String,  String>> sampleMap2 = null;
    CompletableFuture<Map<String,  String>> sampleMap3 = null;
    sampleMap1 = getSampleMap1(param1, param2);
    sampleMap2 = getSampleMap2(param1, param2);
    sampleMap3 = getSampleMap3(param1, param2);         
    // Wait until they are all done
    CompletableFuture.allOf(sampleMap1, sampleMap2, sampleMap3).join();         
}
@Async("asyncExecutor")
    public CompletableFuture<Map<String, String>> getSampleMap1(String param1, String param2) throws InterruptedException {
    System.out.println("Inside  Method1");
    ..
    ..
    }   

@Async("asyncExecutor")
    public CompletableFuture<Map<String, String>> getSampleMap2(String param1, String param2) throws InterruptedException {
    System.out.println("Inside  Method2");
    ..
    ..
    }

@Async("asyncExecutor")
    public CompletableFuture<Map<String, String>> getSampleMap3(String param1, String param2) throws InterruptedException {
    System.out.println("Inside  Method3");
    ..
    ..
    }   

线程名称未显示且异步进程未发生 日志：

[           main]o.s.s.concurrent.ThreadPoolTaskExecutor   Initializing ExecutorService
[           main]o.s.s.concurrent.ThreadPoolTaskExecutor   Initializing ExecutorService 'asyncExecutor1'
[           main]o.s.s.c.ThreadPoolTaskScheduler           Initializing ExecutorService 'taskScheduler'
[           main]o.s.b.w.embedded.tomcat.TomcatWebServer   Tomcat started on port(s): 32182 (http) with context path '/myapplication'
[           main]MyMainApplication  Started MyMainApplication in 46.662 seconds (JVM running for 48.024)
 [exec-1]e-myapplication]  Initializing Spring DispatcherServlet 'dispatcherServlet'
  [exec-1]o.s.web.servlet.DispatcherServlet         Initializing Servlet 'dispatcherServlet'
  [exec-1]o.s.web.servlet.DispatcherServlet         Completed initialization in 8 ms
  [exec-1]Inside - getSampleDetails
  [exec-1]Inside  Method1
  [exec-1]Inside  Method2
  [exec-1]Inside  Method3 

Answer 1

spring在扫描bean时，会扫描方法上是否包含@Async注解。如果包含，spring会为这个bean动态生成一个子类（即代理类，proxy），代理类继承原bean。这时候，被注解的方法被调用的时候，其实是被代理类调用的，代理类在调用的时候加入了异步效果。但是如果这个注解的方法被同一个类中的其他方法调用，方法调用并没有经过代理类，而是直接通过原始bean，所以没有异步效果，我们看到的现象是@Async注释无效。

你可以试试这样的：

1. 调用和任务应该放在不同的类中。
2. 在启动类中添加注解：@EnableAspectJAutoProxy(exposeProxy = true)
3. 在ServiceManager中，使用AopContext.currentProxy()获取Service的代理类，然后调用事务方法强制通过代理类激活事务切面。