Handle REST client exception for unsupported URL

README.md

@@ -59,6 +59,7 @@ This service provides **IIIF** manifest generation from **DSpace RDF** and/or **
 <details>
 <summary>Example Cantaloupe custom delegate</summary>
 
+```
   require 'base64'
   class CustomDelegate
     ##
@@ -102,6 +103,7 @@ This service provides **IIIF** manifest generation from **DSpace RDF** and/or **
       return uri
     end
   end
+```
 
 </details>
 

src/main/java/edu/tamu/iiif/service/AbstractManifestService.java

@@ -164,11 +164,19 @@ protected Model getRdfModel(String url) throws NotFoundException {
         return createRdfModel(getRdf(url));
     }
 
-    protected String getRdf(String url) throws NotFoundException {
-        Optional<String> rdf = Optional.ofNullable(restTemplate.getForObject(url, String.class));
-        if (rdf.isPresent()) {
-            logger.debug("RDF for {}: \n{}\n", url, rdf.get());
-            return rdf.get();
+    private String getRdf(String url) throws NotFoundException {
+        try {
+            if (logger.isDebugEnabled()) {
+                logger.info("Requesting RDF for {}", url);
+            }
+            Optional<String> rdf = Optional.ofNullable(restTemplate.getForObject(url, String.class));
+            if (rdf.isPresent()) {
+                logger.debug("RDF for {}: \n{}\n", url, rdf.get());
+                return rdf.get();
+            }
+        } catch (RestClientException e) {
+            logger.error("Failed to get RDF for {}: {}", url, e.getMessage());
+            logger.debug("Error while requesting RDF for {}: {}", url, e.getMessage(), e);
         }
         throw new NotFoundException("RDF not found! " + url);
     }