Spring Boot and Spring Integration. Problems

I have a SpringBoot application. I have a dedicated server, where I shall read data by the HTTP GET requests. I configured the http-outbound-config.xml file for Spring Integration module. When I run the following code, everything is fine:

http-outbound-config.xml

<?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:int="http://www.springframework.org/schema/integration"
   xmlns:int-http="http://www.springframework.org/schema/integration/http"
   xsi:schemaLocation="http://www.springframework.org/schema/beans https://www.springframework.org/schema/beans/spring-beans.xsd
    http://www.springframework.org/schema/integration https://www.springframework.org/schema/integration/spring-integration.xsd
    http://www.springframework.org/schema/integration/http https://www.springframework.org/schema/integration/http/spring-integration-http.xsd">

<int:channel id="requestChannel"/>
<int:channel id="replyChannel">
    <int:queue capacity='10'/>
</int:channel>

<int-http:outbound-gateway id="outboundGateway"
                           request-channel="requestChannel"
                           url="http://server/API.jsp?id=1"
                           http-method="GET"
                           expected-response-type="java.lang.String"
                           charset="UTF-8"
                           reply-channel="replyChannel"/>
</beans>

Main Application Class:

package test;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ImportResource;
import ru.eco.products.waste.egr.Integration;

@SpringBootApplication
@ImportResource("/META-INF/spring/integration/http-outbound-config.xml")
public class Application {
    public static void main(String[] args) {
        Integration integration = new Integration();
        integration.start();
        SpringApplication.run(WasteWebClientApplication.class,
                              args
                             );
    }
    
}

Integration class:

package test;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.ImportResource;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.messaging.Message;
import org.springframework.messaging.MessageChannel;
import org.springframework.messaging.PollableChannel;
import org.springframework.messaging.support.MessageBuilder;
import org.springframework.stereotype.Component;
import org.springframework.web.client.RestTemplate;

@Component
@Configuration
public class Integration { 
    public void start() {
        ClassPathXmlApplicationContext
               context = new ClassPathXmlApplicationContext("classpath:META-INF/spring/integration/http-outbound-config.xml");
        context.start();


        MessageChannel requestChannel = context.getBean("requestChannel", MessageChannel.class);
        PollableChannel replyChannel = context.getBean("replyChannel", PollableChannel.class);
        Message<?> message = MessageBuilder.withPayload("").build();
        requestChannel.send(message);
        
        Message<?> receivedMsg = replyChannel.receive();
        System.out.println("RESULT IS : " + receivedMsg.getPayload());
    }
}

BUT, when I try to Autowire MessageChannel and PollableChannel, I receive a null pointer exception.

Integration class(not working example):

package test;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.ImportResource;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.messaging.Message;
import org.springframework.messaging.MessageChannel;
import org.springframework.messaging.PollableChannel;
import org.springframework.messaging.support.MessageBuilder;
import org.springframework.stereotype.Component;
import org.springframework.web.client.RestTemplate;

@Component
@Configuration
public class Integration {
    @Autowired
    @Qualifier("requestChannel")
    MessageChannel requestChannel;
    @Autowired
    @Qualifier("replyChannel")
    PollableChannel replyChannel;
    
    public void start() {
        Message<?> message = MessageBuilder.withPayload("").build();
        requestChannel.send(message);
        
        Message<?> receivedMsg = replyChannel.receive();
        System.out.println("RESULT IS : " + receivedMsg.getPayload()); 
    }
}

1. Question 1: Why Autowiring is not working?
2. Question 2: What is the best way to get data from dedicated server and save it into DB? Such config is ok? I will create a model class for the response and after will save it into DB via JPA.
3. Question 3: I need reading from server works in Async mode. How can I implement it in Spring Boot? So the main idea here is that I will receive a POST method from the UI, and will launch the integration with web-service. After integration will be finished, I need to notify user.
4. Question 4: Maybe Camel will be the best solution here?

Stack: Java 11, Spring Boot, thymeleaf + bootstrap.

Thank you for the answer in advance.