@Configuration
public class AppConfig {
    
    @Bean
    public Message getMassge() {
        return new Message();
    }
    
}

@Controller
public class WebController {
    
    private Message message;
    
    public WebController(Message message) {
        this.message = message;
    }
    
    @GetMapping("/") 
    public @ResponseBody String getStartPage() {
        message.setAddress("Address1");
        message.setSender("Sender1");
        message.setText("Text1");     
        return "Start page";
    }

}

@Controller
public class MainController {
    
    Message message;

    public MainController(Message message) {
        this.message = message;
    }
     
    @GetMapping("/test") 
    public @ResponseBody String getTestPage() {
        System.out.println(message.getAddress() + " " + message.getText() + " " + message.getSender());
        return "Test page";
    }
}