Java – How to inject Spring Bean in thread

javajavabeansmultithreadingspring

I have a running Spring 3 web application. All the beans are correctly injected and everything is working as it should (all web service calls are working properly).

While expanding the application I needed to add threads that can be started & stopped via a web service.

In the thread I need to inject some Spring beans. These beens are services (annotated with @Service). In my applicationContext the beans are detected via a component scan:

<context:component-scan base-package="<package>">
    <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller" />
</context:component-scan>

But when I try to inject the beans (using @Resource) in the thread they are always 'null' (Spring doesn't inject them). The thread is started but fails while initializing.

I also tried injecting them by loading the applicationContext in code: (application context is located in 'src/main/resources')

ClassPathXmlApplicationContext applicationContext = new ClassPathXmlApplicationContext("classpath:*applicationContext.xml");

if(applicationContext.containsBean("BeanName")) {

        beanObject = (BeanClass) applicationContext.getBean("BeanName");

} else {

    //Exception
}

Does anyone have any idea how to inject the beans in the thread? Or isn't it possible to inject beans in a thread?

Thanks in Advance!

Best Answer

It would be better to separate business logic (the code that depends on your services) from the infrastructure code that manages threads.

For example, you can declare a bean that implements Runnable for your business logic and then use it when you need to start a Thread.

However, starting Threads manually is not a good practice as well. It would be better to use thread pools instead. Actually, Spring provides some built-in support for thread pools and asynchronous execution, so that you can leverage it, see 25. Task Execution and Scheduling.

Related Topic