spring boot中设置异步请求默认使用的线程池

1、自定义异步线程池,如果不自定义则使用自带的线程池
（不是真正意义上的线程池，不会复用线程）

@SpringBootApplication
public class AsyncConfigExample{
    @Bean
    WebMvcConfigurer configurer(){
        return new WebMvcConfigurerAdapter(){
            @Override
            public void configureAsyncSupport (AsyncSupportConfigurer configurer) {
                ThreadPoolTaskExecutor t = new ThreadPoolTaskExecutor();
                t.setCorePoolSize(10);
                t.setMaxPoolSize(100);
                t.setQueueCapacity(50);
                t.setAllowCoreThreadTimeOut(true);
                t.setKeepAliveSeconds(120);
                t.initialize();
                configurer.setTaskExecutor(t);
            }
        };
    }
    public static void main (String[] args) {
        SpringApplication.run(AsyncConfigExample.class, args);
    }
}

2、springboot使用异步注解@Async

@Component
public class AsyncExceptionDemo {
    private static final Logger log = LoggerFactory.getLogger(AsyncExceptionDemo.class);
 
    /**
     * 最简单的异步调用，返回值为void
     */
    @Async
    public void asyncInvokeSimplest() {
        log.info("asyncSimplest");
    }
 
    /**
     * 带参数的异步调用 异步方法可以传入参数
     *  对于返回值是void，异常会被AsyncUncaughtExceptionHandler处理掉
     * @param s
     */
    @Async
    public void asyncInvokeWithException(String s) {
        log.info("asyncInvokeWithParameter, parementer={}", s);
        throw new IllegalArgumentException(s);
    }
 
    /**
     * 异常调用返回Future
     *  对于返回值是Future，不会被AsyncUncaughtExceptionHandler处理，需要我们在方法中捕获异常并处理
     *  或者在调用方在调用Futrue.get时捕获异常进行处理
     * 
     * @param i
     * @return
     */
    @Async
    public Future<String> asyncInvokeReturnFuture(int i) {
        log.info("asyncInvokeReturnFuture, parementer={}", i);
        Future<String> future;
        try {
            Thread.sleep(1000 * 1);
            future = new AsyncResult<String>("success:" + i);
            throw new IllegalArgumentException("a");
        } catch (InterruptedException e) {
            future = new AsyncResult<String>("error");
        } catch(IllegalArgumentException e){
            future = new AsyncResult<String>("error-IllegalArgumentException");
        }
        return future;
    }
 
}

3、实现AsyncConfigurer接口对异常线程池更加细粒度的控制
a) 创建线程自己的线程池
b) 对void方法抛出的异常处理的类AsyncUncaughtExceptionHandler

/**
 * 通过实现AsyncConfigurer自定义异常线程池，包含异常处理
 * 
 * @author hry
 *
 */
@Service
public class MyAsyncConfigurer implements AsyncConfigurer{
    private static final Logger log = LoggerFactory.getLogger(MyAsyncConfigurer.class);
 
    @Override
    public Executor getAsyncExecutor() {
        ThreadPoolTaskExecutor threadPool = new ThreadPoolTaskExecutor();  
        threadPool.setCorePoolSize(1);  
        threadPool.setMaxPoolSize(1);  
        threadPool.setWaitForTasksToCompleteOnShutdown(true);  
        threadPool.setAwaitTerminationSeconds(60 * 15);  
        threadPool.setThreadNamePrefix("MyAsync-");
        threadPool.initialize();
        return threadPool;  
    }
 
    @Override
    public AsyncUncaughtExceptionHandler getAsyncUncaughtExceptionHandler() {
         return new MyAsyncExceptionHandler();  
    }
 
    /**
     * 自定义异常处理类
     * @author hry
     *
     */
    class MyAsyncExceptionHandler implements AsyncUncaughtExceptionHandler {  
 
        @Override  
        public void handleUncaughtException(Throwable throwable, Method method, Object... obj) {  
            log.info("Exception message - " + throwable.getMessage());  
            log.info("Method name - " + method.getName());  
            for (Object param : obj) {  
                log.info("Parameter value - " + param);  
            }  
        }  
 
    } 
 
}

@SpringBootApplication
@EnableAsync // 启动异步调用
public class AsyncApplicationWithAsyncConfigurer {
    private static final Logger log = LoggerFactory.getLogger(AsyncApplicationWithAsyncConfigurer.class);
 
    public static void main(String[] args) {
        log.info("Start AsyncApplication.. ");
        SpringApplication.run(AsyncApplicationWithAsyncConfigurer.class, args);
    }
 
 
}