To use spring MVC in spring boot, you only need to introduce spring boot starter web (provided that the pom file of the project is inherited from spring boot starter parent):

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

Then you can configure some parameters of springmvc in the application.properties file, such as the path to load jsp, etc

spring.mvc.view.prefix=/WEB-INF/jsp
spring.mvc.view.suffix=.jsp

If some of our variables need to be referenced in the form of ${xxx} in jsp (note that here is jsp, not freemarker, etc., freemarker's configuration mode is later), and the values of these variables are assigned in java code, we can use @ ControllerAdvice annotation, and cooperate with UrlBasedViewResolver object and @ PostConstruct, @ InitBinder and other annotations to achieve Our effect:

@ControllerAdvice
public class SpringmvcConfiguration {

    @Autowired
    UrlBasedViewResolver urlBasedViewResolver;

    @PostConstruct
    void init(){
        //Configure the variables in the request that can be used by ${} to ↓ to ↓ to ↓ to ↓ to ↓ to ↓ to ↓ to ↓ to ↓ to ↓ to ↓ to be used by ${} to be used
        Map<String, Object> m = new HashMap<>();
        m.put("xxx", "xxx");
        urlBasedViewResolver.setAttributesMap(m);
    }

    //The parameter converters of springmvc are configured here. Each parameter converter inherits from the PropertyEditorSupport class
    @InitBinder
    public void bind(WebDataBinder binder) {
        binder.registerCustomEditor(Date.class, new DateConvertEditor());
        binder.registerCustomEditor(List.class, new StringListConvertEditor());
        binder.registerCustomEditor(int.class, new IntegerConvertEditor());
        binder.registerCustomEditor(String[].class, new StringListConvertEditor());
        binder.registerCustomEditor(boolean.class, new BooleanConvertEditor());
    }

}

The above example also shows how to inject a parameter converter into spring MVC. For example, we need to convert the string "2018-3-9 17:48:00" passed in the foreground to a Date object, and the above DateConvertEditor class can complete the conversion.

If you want to inject variables in freemarker or use shiro tag, we can use FreeMarkerConfigurer object to implement:

@Configuration("Mv6gFBYZ3VDmPeSjTpQC")
public class ShiroTagFreeMarkerConfigurer implements InitializingBean {

    @Autowired
    FreeMarkerConfigurer freeMarkerConfigurer;

    @Override
    public void afterPropertiesSet() throws IOException, TemplateException {
        //You can use shiro tags in ftl files
        freeMarkerConfigurer.getConfiguration().setSharedVariable("shiro", new ShiroTags());
        //It can be found in the ftl file
        freeMarkerConfigurer.getConfiguration().setSharedVariable("xxx", "xxx");
    }

}

At this point, if we want to use the shiro tag in freemarker, we can do this:

<@shiro.hasPermission name="quanxian">
</@shiro.hasPermission>

Similarly, if you need to use the xxx variable registered above, you can:

${xxx}