spring-projects/spring-integration

Hi everyone, we are migrating our app from spring boot 1.3.8 to 2.2.9 and having issues with the spring integration which used to work perfectly fine with an older version. It's throwing an exception with BeanFactory must not be null message, when our code triggers the spring integration method from an interface with @MessagingGateway annotation. I have created a sample project using spring initialzr, then added a simple configuration class with spring integration beans and I can able to reproduce the issue. Please find the following code for reference. @artembilan Any thoughts?

HelloController.java

package com.springintegration.sample;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import com.springintegration.sample.SpringIntegrationConfig.TestGateway;
import com.springintegration.sample.util.StringUtil;

@RestController
public class HelloController {

    @Autowired
    private ConfigurableApplicationContext applicationContext;

    @RequestMapping("/hello")
    public String index() {

        TestGateway testGateway = applicationContext.getBean(TestGateway.class);
        try {
            testGateway.processRequest("Spring Integration");

        } catch (Exception e) {
            System.err.println("Error during the hello endpoint call: "
                    + e.getMessage());
            System.err.println(StringUtil.stackTraceToString(e));


        }
        return "Greetings from Spring Boot!";
    }

}

SpringIntegrationConfig .java

package com.springintegration.sample;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.integration.annotation.Gateway;
import org.springframework.integration.annotation.IntegrationComponentScan;
import org.springframework.integration.annotation.MessagingGateway;
import org.springframework.integration.annotation.Transformer;
import org.springframework.integration.channel.DirectChannel;
import org.springframework.integration.config.EnableIntegration;
import org.springframework.integration.handler.ServiceActivatingHandler;
import org.springframework.integration.transformer.MethodInvokingTransformer;
import org.springframework.messaging.MessageChannel;
import org.springframework.messaging.MessageHandler;

import com.springintegration.sample.service.TempService;

@Configuration
@EnableIntegration
@IntegrationComponentScan
public class SpringIntegrationConfig {
    @MessagingGateway
    public interface TestGateway {
        @Gateway(requestChannel="testInputChannel", replyChannel="testOutputChannel")
        String processRequest(String request);
    }

    @Bean
    public MessageChannel testInputChannel() {
        System.out.println("In testInputChannel");
        return new DirectChannel();
    }

    @Bean
    public MessageChannel testOutputChannel() {
        System.out.println("In testOutputChannel");
        return new DirectChannel();
    }

    @Transformer(inputChannel="testInputChannel")
    @Bean
    public MessageHandler validationTransform() {
        ServiceActivatingHandler activatingHandler = new ServiceActivatingHandler(new MethodInvokingTransformer(tempService(), "testMethod"));
        activatingHandler.setOutputChannel(testOutputChannel());
        return activatingHandler;
    }

    @Bean
    public TempService tempService(){
        return new TempService();
    }
}

TempService.java

package com.springintegration.sample.service;

public class TempService {
    public void testMethod(String s) {
        System.out.println("TempService --- "+ s );
    }

}