How to make webjars version agnostic in spring mvc - spring

Question

I have followed the documentation on their website as described here
First of all I added the required path
<mvc:resources mapping="/webjars/**" location="/webjars/"/>
then I created a controller with the following
#ResponseBody
#RequestMapping("/webjarslocator/{webjar}/**")
public ResponseEntity locateWebjarAsset(#PathVariable String webjar, HttpServletRequest request) {
try {
String mvcPrefix = "/webjarslocator/" + webjar + "/"; // This prefix must match the mapping path!
String mvcPath = (String) request.getAttribute(HandlerMapping.PATH_WITHIN_HANDLER_MAPPING_ATTRIBUTE);
String fullPath = assetLocator.getFullPath(webjar, mvcPath.substring(mvcPrefix.length()));
return new ResponseEntity(new ClassPathResource(fullPath), HttpStatus.OK);
} catch (Exception e) {
return new ResponseEntity<>(HttpStatus.NOT_FOUND);
}
}
Few dependencies were missing so I added in maven the following pom
<dependency>
<groupId>org.webjars</groupId>
<artifactId>webjars-locator</artifactId>
<version>0.28</version>
</dependency>
The above will import the following
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.servlet.HandlerMapping;
import org.springframework.core.io.ClassPathResource;
None of these has been imported from the external jar.
The error is: assetLocator cannot be resolved
EDIT: It could be that I need to create a filter rather than put it in a controller. Any thoughts on this?

Answer 1

The documentation is quite sparse, but you can create an instance of an asset locator with new WebJarAssetLocator().

Answer 2

Here's another solution, considering more recent versions of WebJar, in a similar vein for anyone else who stumbles upon this question. Using org.webjars.play.WebJarsUtil#locate(java.lang.String, java.lang.String) (which, in-turn, uses org.webjars.WebJarAssetLocator#getFullPath(java.lang.String, java.lang.String)) accepts the WebJar name (which acts as a scope) and the file without needing to provide a full path that necessitates including the version.