Issue
I want to make the Request Mappings in my Spring application dynamic. So that my url can not be understandable. And I can show anything meaningless to the user and still mapping purpose will be resolved.
For that I am storing the dynamic part of the URL in properties file. And want to use that in the @RequestMapping annotation. And the same thing will be done on the client side in JSP. I will read the value from the property file and then create the href.
I am using @Value annotation to read the property file values.
There is one class that holds all such values in final static variables.
public class UrlMappingAbstraction {
public static final @Value("#{urlAbstractionProperties['url.message']?:'message'}") String MESSAGE = "";
}
And I am extending this class in my controller and using the static final field in the @RequestMapping annotation like below.
@RequestMapping(value="/"+MESSAGE+"/{id}", method=RequestMethod.GET)
And in jsp also I am reading the value from property file using <spring:message/> and generating the url in href.
The problem is jsp able to create the correct url based on the property file value but in the @RequestMapping annotation my value is not getting replaced.
Can anybody tell me the exact problem? I know that we can not change the value of static final variable after its initialized. Then what's the use of @Value annotation.
If this can be done another way then you can also show me it.
Thanks in advance.
Solution
Annotations are static by their nature, therefore you cannot do it this way.
@Value cannot be used on static fields, but it doesn't matter here - the real problem is that there is no way to use values other than compile time constants as attributes of annotations.
You can use one of the following alternatives:
Add a URL rewrite filter (such as this or this) and configure it to perform the necessary conversion.
This approach looks more elegant due to clear separation of responsibilities - controllers are responsible for doing their jobs, rewrite filter is responsible for obfuscation of URLs.
Intercept creation of controller mappings by overriding
RequestMappingHandlerMapping. getMappingForMethod()and change their URL patterns at this step (not tested)
Answered By - axtavt
Answer Checked By - David Goodson (JavaFixing Volunteer)
