Can I inject other thread into Spring boot ThreadPool

Question

I am working on a JPOS project using Q2's ISORequestListener. When I received an ISOMsg, I want to start a backend service thread. But the backend service always return null and spring beans can not be autowired within ISORequestlistner (I am following this).

Is there anyway I can inject backend service to ThreadPool at the beginning of Spring Boot?

This is my current listener:

@Component
    public class ISO8583Listener implements ISORequestListener {
    @Autowired
    private BackendServ backendServ ;


    public ISO8583Listener() {
            AutowiredAnnotationBeanPostProcessor bpp = new 
                        AutowiredAnnotationBeanPostProcessor();
            WebApplicationContext currentContext = 
                        WebApplicationContextLocator.getCurrentWebApplicationContext();
            bpp.setBeanFactory(currentContext.getAutowireCapableBeanFactory());
            bpp.processInjection(this);
    }

    @Override
    public boolean process (ISOSource source, ISOMsg m) {
        try {
            if ("200".equals (m.getMTI())) {
                //some backend service process here

                //end

                m.setResponseMTI();
                source.send(m);
            } 
        } catch (ISOException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return true;
    }

And my configuration:

    @Configuration
    public class WebApplicationContextLocator implements ServletContextInitializer {
        private static WebApplicationContext webApplicationContext;

        public static WebApplicationContext getCurrentWebApplicationContext() {
            return webApplicationContext;
        }

        @Override
        public void onStartup(ServletContext servletContext) throws ServletException {
          webApplicationContext = 
                WebApplicationContextUtils.getWebApplicationContext(servletContext);
        }
    }

Answer 1

One way to achieve what you are trying to do, is by registering the backendServ in the NameRegistrar and then get it in the request listener constructor. It wouldn´t be a component since it is created by the jPOS framework not the Spring framework:

package com.example.jpos_demo;

import org.jpos.iso.ISOMsg;
import org.jpos.iso.ISORequestListener;
import org.jpos.iso.ISOSource;
import org.jpos.util.NameRegistrar;

public class DemoRequestListener implements ISORequestListener {
    BackendServ serv;

    public DemoRequestListener() throws NameRegistrar.NotFoundException {
        serv = NameRegistrar.get("serv", 1000L); /
    }
    
    @Override
    public boolean process(ISOSource isoSource, ISOMsg isoMsg) {
        try {
            if ("200".equals (m.getMTI())) {
                //some backend service process here

                //end

                m.setResponseMTI();
                source.send(m);
            } 
        } catch (ISOException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return true;
    }
}

To register the BackendServ in NameRegistrar just write the following code next to where you instantiate your bean:

NameRegistrar.register("serv", backendServ);

One last word, this won't work, and I don't know a workaround, for spring-dev-tools, this is because of the way spring-dev-tools handles the classloader for the hot reload.