Spring 4 Async not working - spring

Question

I am working on a Spring 4 web application and have run into a problem with #Async running synchronously. This is 100% annotation driven. No XML files.
App:
package com.kc2112.app;
import com.kc2112.app.controllers.MyStopWatch;
import javax.annotation.Resource;
import org.springframework.aop.interceptor.AsyncUncaughtExceptionHandler;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.task.TaskExecutor;
import org.springframework.scheduling.annotation.AsyncConfigurer;
import org.springframework.scheduling.annotation.EnableAsync;
import org.springframework.scheduling.annotation.EnableScheduling;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;
#EnableAsync
#EnableScheduling
#Configuration
public class WebApp extends AbstractAnnotationConfigDispatcherServletInitializer implements AsyncConfigurer {
#Resource
#Qualifier("stopwatch")
public MyStopWatch stopwatch;
public WebApp() {
super();
stopwatch = new MyStopWatch();
}
#Override
protected Class<?>[] getRootConfigClasses() {
return new Class<?>[0];
}
#Override
protected Class<?>[] getServletConfigClasses() {
return new Class<?>[]{AppConfig.class};
}
#Override
protected String[] getServletMappings() {
return new String[]{"/"};
}
#Override
public TaskExecutor getAsyncExecutor() {
ThreadPoolTaskExecutor te = new ThreadPoolTaskExecutor();
te.setMaxPoolSize(25);
te.setThreadNamePrefix("LULExecutor-");
te.initialize();
return te;
}
#Override
public AsyncUncaughtExceptionHandler getAsyncUncaughtExceptionHandler() {
return null;
}
}
Configuration:
package com.kc2112.app;
import com.kc2112.app.controllers.MySampleService;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.FilterType;
import org.springframework.context.support.PropertySourcesPlaceholderConfigurer;
import org.springframework.scheduling.annotation.EnableAsync;
import org.springframework.web.servlet.view.InternalResourceViewResolver;
import org.springframework.web.servlet.view.JstlView;
import org.springframework.web.servlet.view.UrlBasedViewResolver;
#Configuration
#EnableAsync
#ComponentScan( basePackages = {"com"}, excludeFilters={
#ComponentScan.Filter(type=FilterType.ASSIGNABLE_TYPE, value=MySampleService.class)} )
public class AppConfig{
#Bean
public static PropertySourcesPlaceholderConfigurer properties() {
return new PropertySourcesPlaceholderConfigurer();
}
#Bean
public UrlBasedViewResolver urlBasedViewResolver()
{
UrlBasedViewResolver res = new InternalResourceViewResolver();
res.setViewClass(JstlView.class);
res.setPrefix("/WEB-INF/jsp/");
res.setSuffix(".jsp");
return res;
}
}
Controller:
package com.kc2112.app.controllers;
import java.util.ArrayList;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
#RestController
public class MyAsyncController {
#Autowired
MyStopWatch stopwatch;
public MySampleService mySampleService = new MySampleService();
#RequestMapping(value = "/go", produces = {MediaType.TEXT_HTML_VALUE}, method = RequestMethod.GET)
public String taskExecutor() throws InterruptedException, ExecutionException {
ArrayList<Future<Boolean>> asyncResults = new ArrayList();
for (int i = 0; i < 10; i++) {
asyncResults.add(mySampleService.callAsync(i));
}
return "time passed is " + stopwatch.getTime();
}
}
Component:
package com.kc2112.app.controllers;
import java.util.concurrent.Future;
import org.springframework.scheduling.annotation.Async;
import org.springframework.scheduling.annotation.AsyncResult;
import org.springframework.stereotype.Component;
#Component
public class MySampleService {
#Async
public Future<Boolean> callAsync(int taskCall) throws InterruptedException {
System.out.println("starting thread" + taskCall);
for (int i = 0; i < 10; i++) {
System.out.println("thread " + taskCall + " count is " + i);
}
return new AsyncResult<Boolean>(true);
}
}
Stopwatch:
package com.kc2112.app.controllers;
import org.apache.commons.lang.time.StopWatch;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Component;
import org.springframework.stereotype.Service;
#Component
#Service
#Qualifier("stopwatch")
public class MyStopWatch extends StopWatch {
public MyStopWatch(){
super();
this.start();
}
}
I've tried a multitude of things, but it always prints results which are obviously not async.

Answer 1

public MySampleService mySampleService = new MySampleService();
This is the cause of your troubles. You must autowire the MySampleService into your controller instead of creating an instance yourself. That's the only way for Spring to wrap the component into an async proxy that will detect the annotation, intercept the method call, create a task and submit it to an executor.

Answer 2

YES!!!! After reading through this post:
Spring ThreadPoolTaskExecutor only running one thread
I made a few changes to my app class. The critical issue appears to be to set the core pool size. Here is the class with the line that fixed the issue...
Here's the spring docs on it:
http://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/scheduling/concurrent/ThreadPoolTaskExecutor.html#setCorePoolSize-int-
package com.kc2112.app;
import com.kc2112.app.controllers.MyStopWatch;
import javax.annotation.Resource;
import org.springframework.aop.interceptor.AsyncUncaughtExceptionHandler;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.task.TaskExecutor;
import org.springframework.scheduling.annotation.AsyncConfigurer;
import org.springframework.scheduling.annotation.EnableAsync;
import org.springframework.scheduling.annotation.EnableScheduling;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;
#EnableAsync
#EnableScheduling
#Configuration
public class WebApp extends AbstractAnnotationConfigDispatcherServletInitializer implements AsyncConfigurer {
#Resource
#Qualifier("stopwatch")
public MyStopWatch stopwatch;
public WebApp() {
super();
stopwatch = new MyStopWatch();
}
#Override
protected Class<?>[] getRootConfigClasses() {
return new Class<?>[0];
}
#Override
protected Class<?>[] getServletConfigClasses() {
return new Class<?>[]{AppConfig.class};
}
#Override
protected String[] getServletMappings() {
return new String[]{"/"};
}
#Override
public TaskExecutor getAsyncExecutor() {
ThreadPoolTaskExecutor te = new ThreadPoolTaskExecutor();
te.setMaxPoolSize(25);
te.setThreadNamePrefix("LULExecutor-");
te.setCorePoolSize(25); //This was the critical line...
te.initialize();
return te;
}
#Override
public AsyncUncaughtExceptionHandler getAsyncUncaughtExceptionHandler() {
return null;
}
}