Asynchronous method invocation in Spring Framework

Since Spring 3.0, annotation support for both task scheduling and asynchronous method execution has been added. The post will give a demo of @Async annotation and its uses.

@Service – annotate classes at service layer level.
@Async – put @Async annotation above the method in an asynchronous process.

To define a void async method


@Async
public void methodAsync1() {
// add logic
}

@Async

public void methodAsync1() {

// add logic

}

To define an asynchronous method which return something. To achieve it, the method shall return a java.util.concurrent.Future object, and the implementation shall return a new AsyncResult object () let’s use Accountclass:


@Async
public Future<Account> methodAsync2() {
    // .... logic here ....
    Account account = ....
    return new AsyncResult<Account>(account);
}

@Async

public Future<Account> methodAsync2() {

// .... logic here ....

Account account = ....

return new AsyncResult<Account>(account);

}

To retrieve the object saved in Future object


Account account = future.get();

Account account = future.get();


package net.tecbar.asynchronous;

import org.apache.log4j.Logger;
import org.springframework.scheduling.annotation.Async;
import org.springframework.stereotype.Service;

@Service
public class OrderHandler {
	private static final Logger LOG = Logger.getLogger(OrderHandler.class); 
	
	@Async
	public void processOrder() {
		LOG.info("start processOrder");
		
		try {
			Thread.sleep(5000); // use 5 seconds to emulate the operation time
		} catch (InterruptedException e) {
			LOG.error(e.getMessage(), e);
		}
		
		LOG.info("end processOrder");
	}
}

package net.tecbar.asynchronous;

import org.apache.log4j.Logger;

import org.springframework.scheduling.annotation.Async;

import org.springframework.stereotype.Service;

@Service

public class OrderHandler {

private static final Logger LOG = Logger.getLogger(OrderHandler.class);

@Async

public void processOrder() {

LOG.info("start processOrder");

try {

Thread.sleep(5000); // use 5 seconds to emulate the operation time

} catch (InterruptedException e) {

LOG.error(e.getMessage(), e);

}

LOG.info("end processOrder");

}

Bean Configuration


<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:task="http://www.springframework.org/schema/task"
	xsi:schemaLocation="
    http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd
    http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task-3.0.xsd">
	<!-- <context:component-scan base-package="tv.blackarrow.cip.service"/> -->
	<bean id="orderHandler" class="net.tecbar.asynchronous.OrderHandler">
	</bean>
	<task:annotation-driven />
</beans>

<?xml version="1.0" encoding="UTF-8"?>

<beans xmlns="http://www.springframework.org/schema/beans"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"

xmlns:context="http://www.springframework.org/schema/context"

xmlns:task="http://www.springframework.org/schema/task"

xsi:schemaLocation="

http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd

http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd

http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task-3.0.xsd">

</bean>

<task:annotation-driven />

</beans>

client


package net.tecbar.asynchronous;

import org.apache.log4j.Logger;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class OrderClient {
	private static final Logger LOG = Logger.getLogger(OrderClient.class);

	public static void main(String[] args) {
		ClassPathXmlApplicationContext ctx = new ClassPathXmlApplicationContext("conf/async_beans.xml");
		OrderHandler handler = (OrderHandler)ctx.getBean("orderHandler");
		LOG.info("call handler processOrderMethod");
		handler.processOrder();
		LOG.info("continue execute...");
	}

}

package net.tecbar.asynchronous;

import org.apache.log4j.Logger;

import org.springframework.context.support.ClassPathXmlApplicationContext;

public class OrderClient {

private static final Logger LOG = Logger.getLogger(OrderClient.class);

public static void main(String[] args) {

ClassPathXmlApplicationContext ctx = new ClassPathXmlApplicationContext("conf/async_beans.xml");

OrderHandler handler = (OrderHandler)ctx.getBean("orderHandler");

LOG.info("call handler processOrderMethod");

handler.processOrder();

LOG.info("continue execute...");

}

Log output


15:27:50,750 INFO  [OrderClient]:12 - call handler processOrderMethod
15:27:50,754 INFO  [OrderClient]:14 - continue execute...
15:27:50,767 INFO  [OrderHandler]:13 - start processOrder
15:27:55,767 INFO  [OrderHandler]:21 - end processOrder