Spring MVC - DeferredResultProcessingInterceptor Examples

package com.logicbig.example;

import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.context.request.async.DeferredResult;
import org.springframework.web.context.request.async.DeferredResultProcessingInterceptor;

public class MyDeferredResultProcessingInterceptor implements
          DeferredResultProcessingInterceptor {


    @Override
    public <T> void beforeConcurrentHandling (NativeWebRequest request,
                                              DeferredResult<T> deferredResult)
              throws Exception {
        System.out.println("deferredInterceptor#beforeConcurrentHandler called." +
                                     "Thread: " + Thread.currentThread().getName());

    }

    @Override
    public <T> void preProcess (NativeWebRequest request,
                                DeferredResult<T> deferredResult) throws Exception {
        System.out.println("deferredInterceptor#preProcess called." +
                                     "Thread: " + Thread.currentThread().getName());

    }

    @Override
    public <T> void postProcess (NativeWebRequest request,
                                 DeferredResult<T> deferredResult,
                                 Object concurrentResult) throws Exception {
        System.out.println("deferredInterceptor#postProcess called." +
                                     "Thread: " + Thread.currentThread().getName());

    }

    @Override
    public <T> boolean handleTimeout (NativeWebRequest request,
                                      DeferredResult<T> deferredResult) throws Exception {
        System.out.println("deferredInterceptor#handleTimeout called." +
                                     "Thread: " + Thread.currentThread().getName());

        return false;
    }

    @Override
    public <T> void afterCompletion (NativeWebRequest request,
                                     DeferredResult<T> deferredResult) throws Exception {
        System.out.println("deferredInterceptor#afterCompletion called." +
                                     "Thread: " + Thread.currentThread().getName());

    }
}

package com.logicbig.example;

import org.springframework.web.context.request.async.WebAsyncManager;
import org.springframework.web.context.request.async.WebAsyncUtils;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;


public class MyAsyncHandlerInterceptor extends HandlerInterceptorAdapter {
    private static final Object DEFERRED_INTERCEPTOR_KEY = new Object();

    @Override
    public boolean preHandle (HttpServletRequest request,
                              HttpServletResponse response,
                              Object handler) throws Exception {

        System.out.println("interceptor#preHandle called." +
                                     " Thread: " + Thread.currentThread()
                                                         .getName());

        WebAsyncManager asyncManager = WebAsyncUtils.getAsyncManager(request);
        asyncManager.registerDeferredResultInterceptor(DEFERRED_INTERCEPTOR_KEY,
                                                       new MyDeferredResultProcessingInterceptor());


        return true;

    }

    @Override
    public void postHandle (HttpServletRequest request,
                            HttpServletResponse response,
                            Object handler,
                            ModelAndView modelAndView) throws Exception {

        System.out.println("interceptor#postHandle called." +
                                     "Thread: " + Thread.currentThread()
                                                        .getName());
    }

    @Override
    public void afterCompletion (HttpServletRequest request,
                                 HttpServletResponse response,
                                 Object handler, Exception ex) throws Exception {

        System.out.println("interceptor#afterCompletion called Thread.: " +
                                     Thread.currentThread()
                                           .getName());
    }

    @Override
    public void afterConcurrentHandlingStarted (HttpServletRequest request,
                                                HttpServletResponse response,
                                                Object handler) throws Exception {

        System.out.println("interceptor#afterConcurrentHandlingStarted called. " +
                                     "Thread: " + Thread.currentThread()
                                                        .getName());
    }
}

package com.logicbig.example;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.context.request.async.DeferredResult;

@Controller
public class MyWebController {
    @RequestMapping("/")
    @ResponseBody
    public DeferredResult<String> handleTestRequest () {

        System.out.println("controller#handler called. Thread: " +
                                     Thread.currentThread()
                                           .getName());

        final DeferredResult<String> deferredResult = new DeferredResult<>();

        new Thread(() -> {
            System.out.println("controller-deferred#async task started. Thread: " +
                                         Thread.currentThread()
                                               .getName());
            try {
                Thread.sleep(300);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            deferredResult.setResult("test async result");
            System.out.println("controller-deferred#async task finished");
        }).start();


        System.out.println("controller#handler finished");
        return deferredResult;
    }
}

package com.logicbig.example;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;

public class Main {
    public static void main (String[] args) {
        SpringApplication.run(BootApplication.class, args);
    }

    @SpringBootApplication
    public static class BootApplication extends WebMvcConfigurerAdapter {
        @Override
        public void addInterceptors (InterceptorRegistry registry) {
            registry.addInterceptor(new MyAsyncHandlerInterceptor());
        }
    }
}

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 <modelVersion>4.0.0</modelVersion>


 <groupId>com.logicbig.example</groupId>
 <artifactId>async-deferred-process-interceptor</artifactId>
 <version>1.0-SNAPSHOT</version>

 <parent>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-parent</artifactId>
  <version>1.4.2.RELEASE</version>
 </parent>

 <properties>
  <java.version>1.8</java.version>
 </properties>
 <dependencies>
  <dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-web</artifactId>
  </dependency>
 </dependencies>


</project>