1.實現一個介面

@RestController
public class LocalController {
    private static final Log log = LogFactory.getLog(MethodHandles.lookup().lookupClass());

    @RequestMapping("/ac")
    public WebAsyncTask<String> asyncTest() {
        Callable<String> callable = () -> {
            Thread.sleep(1000);
            log.info("-----asyncTest-----");
            return "success";
        };

        return new WebAsyncTask<>(callable);
    }
}
 

非常簡單

2.我們可以自定義非同步的執行緒池，超時設定和Interceptor攔截器

@Configuration
public class WebMvcConfig extends WebMvcConfigurerAdapter {
    /**
     * 攔截器
     * @param registry
     */
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new AsynInterceptor()).addPathPatterns("/**");
        super.addInterceptors(registry);
    }

    /**
     * 非同步設定
     * @param configurer
     */
    @Override
    public void configureAsyncSupport(final AsyncSupportConfigurer configurer) {
        configurer.setDefaultTimeout(60 * 1000L);
        configurer.registerCallableInterceptors(timeoutInterceptor());
        configurer.setTaskExecutor(threadPoolTaskExecutor());
    }

    /**
     * 超時攔截器
     * @return
     */
    @Bean
    public TimeoutCallableProcessingInterceptor timeoutInterceptor() {
        return new TimeoutCallableProcessingInterceptor();
    }

    /**
     * 執行緒池
     * @return
     */
    @Bean
    public ThreadPoolTaskExecutor threadPoolTaskExecutor() {
        ThreadPoolTaskExecutor t = new ThreadPoolTaskExecutor();
        t.setCorePoolSize(10);
        t.setMaxPoolSize(50);
        t.setThreadNamePrefix("YJH");
        return t;
    }
}
 

攔截器程式碼

public class AsynInterceptor extends HandlerInterceptorAdapter {
    private static final Log log = LogFactory.getLog(MethodHandles.lookup().lookupClass());

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        log.info("preHandle");
        return super.preHandle(request, response, handler);
    }


    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        log.info("postHandle");
        super.postHandle(request, response, handler, modelAndView);
    }

    /**
     * 用於處理非同步請求，當Controller中有非同步請求方法的時候會觸發該方法時，
     * 非同步請求先支援preHandle、然後執行afterConcurrentHandlingStarted。
     * 非同步執行緒完成之後執行preHandle、postHandle、afterCompletion。
     * @param request
     * @param response
     * @param handler
     * @throws Exception
     */
    @Override
    public void afterConcurrentHandlingStarted(HttpServletRequest request,
                                               HttpServletResponse response, Object handler) throws Exception {
        log.info("afterConcurrentHandlingStarted");
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response,
                                Object handler, Exception ex) throws Exception {
        log.info("afterCompletion");

    }
}
 

會發現，非同步請求先支援preHandle、然後執行afterConcurrentHandlingStarted。非同步執行緒完成之後執行preHandle、postHandle、afterCompletion。

3.實現一個Filter

@Slf4j
@Order(2)
@WebFilter(urlPatterns = {"/*"}, filterName = "allFilter", asyncSupported = true)
public class AllFilter implements Filter {
    @Override
    public void init(FilterConfig arg0) throws ServletException {
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        try {
            log.info("before doFilter");

            chain.doFilter(request, response);
        } finally {
            // 判斷是否非同步
            if (isAsyncStarted((HttpServletRequest) request) || request.isAsyncStarted()) {
                log.info("AllFilter is async");
                return;
            }

            log.info("finally doFilter");
        }
    }

    @Override
    public void destroy() {

    }

    protected boolean isAsyncStarted(HttpServletRequest request) {
        return WebAsyncUtils.getAsyncManager(request).isConcurrentHandlingStarted();
    }
}

asyncSupported = true一定要設定，否則會報錯。