Dentro de um controller:

    @Autowired
    private UserRepository userRepository;

    @Autowired
    public ApplicationContext context;

    @GetMapping("/users")
    public List<User> getUser(){

        return userRepository.findAll();
    }

    @GetMapping("/gambiarra")
    public List<User> test(){

        return ((UserController) context.getBean("userController")).getUser();
    }

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.tcs.spring</groupId>
    <artifactId>learnspring</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.1.6.RELEASE</version>
        </dependency>
    </dependencies>
</project>

import com.tcs.spring.Printador;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Exemplo {

    public static void main(String[] args) {
        new Exemplo().start();
    }

    public void start() {
        ClassPathXmlApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
        Printador printador = (Printador) ctx.getBean("printador");
        printador.printar();
    }
}

package com.tcs.spring;

public class Printador {
    private String mensagem;

    public void setMensagem(String msg) {
        mensagem = msg;
    }

    public void printar() {
        System.out.println(mensagem);
    };
}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
    <bean id="printador" class="com.tcs.spring.Printador">
        <property name="mensagem" value="Menssagem vinda do XML de maneira magica!"/>
    </bean>
</beans>