Spring and Java Thread example

Java thread images

Here are 3 examples to show you how to do “threading” in Spring. See the code for self-explanatory.

1. Spring + Java Threads example

Create a simple Java thread by extending Thread, and managed by Spring’s container via @Component. The bean scope must be “prototype“, so that each request will return a new instance, to run each individual thread.

PrintThread.java
package com.mkyong.thread;
 
import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Component;
 
@Component
@Scope("prototype")
public class PrintThread extends Thread{
 
	@Override
	public void run() {
 
		System.out.println(getName() + " is running");
		try {
			Thread.sleep(5000);
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
		System.out.println(getName() + " is running");
	}
 
}
AppConfig.java
package com.mkyong.config;
 
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
 
@Configuration
@ComponentScan(basePackages="com.mkyong.thread")
public class AppConfig{
}
App.java
package com.mkyong;
 
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 
import com.mkyong.config.AppConfig;
import com.mkyong.thread.PrintThread;
 
public class App 
{
    public static void main( String[] args )
    {
 
    	ApplicationContext ctx = new AnnotationConfigApplicationContext(AppConfig.class);
 
    	PrintThread printThread1 = (PrintThread) ctx.getBean("printThread");
    	printThread1.setName("Thread 1");
 
    	PrintThread printThread2 = (PrintThread) ctx.getBean("printThread");
    	printThread2.setName("Thread 2");
 
    	PrintThread printThread3 = (PrintThread) ctx.getBean("printThread");
    	printThread3.setName("Thread 3");
 
    	PrintThread printThread4 = (PrintThread) ctx.getBean("printThread");
    	printThread4.setName("Thread 4");
 
    	PrintThread printThread5 = (PrintThread) ctx.getBean("printThread");
    	printThread5.setName("Thread 5");
 
    	printThread1.start();
    	printThread2.start();
    	printThread3.start();
    	printThread4.start();
    	printThread5.start();
 
    }
}

Output – The order will be vary each time, this is thread :)

Thread 3 is running
Thread 2 is running
Thread 1 is running
Thread 5 is running
Thread 4 is running
Thread 2 is running
Thread 4 is running
Thread 5 is running
Thread 3 is running
Thread 1 is running

2. Spring Thread Pool + Spring non-managed bean example

Uses Spring’s ThreadPoolTaskExecutor to create a thread pool. The executing thread is not necessary managed by Spring container.

PrintThread.java – This thread is not managed by Spring, NO @Component
package com.mkyong.thread;
 
public class PrintTask implements Runnable{
 
	String name;
 
	public PrintTask(String name){
		this.name = name;
	}
 
	@Override
	public void run() {
 
		System.out.println(name + " is running");
 
		try {
			Thread.sleep(5000);
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
 
		System.out.println(name + " is running");
	}
 
}
Spring-Config.xml – ThreadPoolTaskExecutor in XML file
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
	xmlns:context="http://www.springframework.org/schema/context"
	xsi:schemaLocation="http://www.springframework.org/schema/beans
	http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
	http://www.springframework.org/schema/context
	http://www.springframework.org/schema/context/spring-context-3.1.xsd">
 
	<bean id="taskExecutor"
		class="org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor">
		<property name="corePoolSize" value="5" />
		<property name="maxPoolSize" value="10" />
		<property name="WaitForTasksToCompleteOnShutdown" value="true" />
	</bean>
 
</beans>
App.java
package com.mkyong;
 
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
 
import com.mkyong.thread.PrintTask;
 
public class App {
  public static void main(String[] args) {
 
    ApplicationContext context = new ClassPathXmlApplicationContext("Spring-Config.xml");
    ThreadPoolTaskExecutor taskExecutor = (ThreadPoolTaskExecutor) context.getBean("taskExecutor");
    taskExecutor.execute(new PrintTask("Thread 1"));
    taskExecutor.execute(new PrintTask("Thread 2"));
    taskExecutor.execute(new PrintTask("Thread 3"));
    taskExecutor.execute(new PrintTask("Thread 4"));
    taskExecutor.execute(new PrintTask("Thread 5"));
 
	//check active thread, if zero then shut down the thread pool
	for (;;) {
		int count = taskExecutor.getActiveCount();
		System.out.println("Active Threads : " + count);
		try {
			Thread.sleep(1000);
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
		if (count == 0) {
			taskExecutor.shutdown();
			break;
		}
	}
 
    }
}

Output – The order will be vary each time.

Thread 1 is running
Thread 2 is running
Thread 3 is running
Thread 4 is running
Active Threads : 4
Thread 5 is running
Active Threads : 5
Active Threads : 5
Active Threads : 5
Active Threads : 5
Thread 2 is running
Thread 1 is running
Thread 3 is running
Thread 4 is running
Thread 5 is running
Active Threads : 0

3. Spring Thread Pool + Spring managed bean example

This example is using ThreadPoolTaskExecutor again, and declares the thread as Spring managed bean via @Component.

The below PrintTask2 is Spring managed bean, you can @Autowired any required beans easily.

PrintTask2.java
package com.mkyong.thread;
 
import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Component;
 
@Component
@Scope("prototype")
public class PrintTask2 implements Runnable{
 
	String name;
 
	public void setName(String name){
		this.name = name;
	}
 
	@Override
	public void run() {
 
		System.out.println(name + " is running");
 
		try {
			Thread.sleep(5000);
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
 
		System.out.println(name + " is running");
 
	}
 
}
AppConfig.java – ThreadPoolTaskExecutor in Spring configuration file
package com.mkyong.config;
 
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
 
@Configuration
@ComponentScan(basePackages = "com.mkyong.thread")
public class AppConfig {
 
	@Bean
	public ThreadPoolTaskExecutor taskExecutor() {
		ThreadPoolTaskExecutor pool = new ThreadPoolTaskExecutor();
		pool.setCorePoolSize(5);
		pool.setMaxPoolSize(10);
		pool.setWaitForTasksToCompleteOnShutdown(true);
		return pool;
	}
 
}
App.java
package com.mkyong;
 
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
 
import com.mkyong.config.AppConfig;
import com.mkyong.thread.PrintTask2;
 
public class App {
  public static void main(String[] args) {
 
    ApplicationContext context = new AnnotationConfigApplicationContext(AppConfig.class);
    ThreadPoolTaskExecutor taskExecutor = (ThreadPoolTaskExecutor) context.getBean("taskExecutor");
 
    PrintTask2 printTask1 = (PrintTask2) context.getBean("printTask2");
    printTask1.setName("Thread 1");
    taskExecutor.execute(printTask1);
 
    PrintTask2 printTask2 = (PrintTask2) context.getBean("printTask2");
    printTask2.setName("Thread 2");
    taskExecutor.execute(printTask2);
 
    PrintTask2 printTask3 = (PrintTask2) context.getBean("printTask2");
    printTask3.setName("Thread 3");
    taskExecutor.execute(printTask3);
 
	for (;;) {
		int count = taskExecutor.getActiveCount();
		System.out.println("Active Threads : " + count);
		try {
			Thread.sleep(1000);
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
		if (count == 0) {
			taskExecutor.shutdown();
			break;
		}
	}
 
   }
}

Output – The order will be vary each time.

Thread 1 is running
Thread 2 is running
Thread 3 is running
Active Threads : 2
Active Threads : 3
Active Threads : 3
Active Threads : 3
Active Threads : 3
Thread 1 is running
Thread 3 is running
Thread 2 is running
Active Threads : 0

Love your comment to improve above program.

Download Source Code

Download it – Spring-Thread-Example.zip (22 KB)

References

  1. Spring scheduling references
  2. ThreadPoolTaskExecutor JavaDoc
  3. Declares bean in Spring Configuration file
  4. How can I shut down the Spring task executor/scheduler pools
  5. Spring Concurrency example
Tags :

About the Author

mkyong
Founder of Mkyong.com and HostingCompass.com, love Java and open source stuff. Follow him on Twitter, or befriend him on Facebook or Google Plus. If you like my tutorials, consider make a donation to these charities.

Comments

  • tony

    GOOD~!~!

  • http://storify.com/williesilvn/sears-auto-coupons-fantastic-discount Sears Auto printable discount coupons

    Simply desire to say your article is as amazing. The clearness in your post is simply spectacular
    and i can assume you’re an expert on this subject. Well with your permission allow me to grab your feed to keep up to date with forthcoming post. Thanks a million and please keep up the rewarding work.

  • http://www.javadiscover.blogspot.com Anand

    Hi All,
    I have placed few Java Multi threading questions with complete java code. Please take a look one who need – http://www.javadiscover.blogspot.com/search/label/Threads

    Thanks
    Anand

  • Naveen

    java.lang.NoClassDefFoundError: and
    Caused by: java.lang.ClassNotFoundException: and
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    Exception in thread “main”

    Kindly provide a solution for this., when i run a java application testcase. I face this issue. Please provide me a solution. Thanks in advance. I see all the necessary jars imported to the workspace and i am using eclipse helios.

  • sagar
    Please can you post some core Java multi-threading examples, its too confusing.
  • http://abdennour-insat.blogspot.com/ Abdennour

    Thank You . Keep Going!

    we can also use the new scope directly which is thread scope :
    http://abdennour-insat.blogspot.com/2012/11/spring-bean-thread-scope.html