This is an exceptional commit message

src/platform/src/main/java/org/geoserver/platform/resource/Resources.java

@@ -390,10 +390,7 @@ public static List<Resource> listRecursively(Resource dir) {
     }
 
     /**
-     * 
      * File Extension based filtering
-     * 
-     *
      */
     public static class ExtensionFilter implements Filter<Resource> {
 

src/rest-ng/src/main/java/org/geoserver/rest/ResourceNotFoundException.java

@@ -1,15 +1,20 @@
 package org.geoserver.rest;
 
+import org.springframework.http.HttpStatus;
+
 /**
- * Handling for 404 type exceptions
+ * Explicit exception for {@link HttpStatus#NOT_FOUND} (404) exceptions.
  */
-public class ResourceNotFoundException extends RuntimeException {
+public class ResourceNotFoundException extends RestException {
+
+    /** serialVersionUID */
+    private static final long serialVersionUID = 4656222203528783838L;
 
     public ResourceNotFoundException() {
-        super();
+        super("Not Found",HttpStatus.NOT_FOUND);
     }
 
-    public ResourceNotFoundException(String s) {
-        super(s);
+    public ResourceNotFoundException(String message) {
+        super(message, HttpStatus.NOT_FOUND);
     }
 }

src/rest-ng/src/main/java/org/geoserver/rest/RestException.java

@@ -1,24 +1,49 @@
+/* (c) 2017 - 2016 Open Source Geospatial Foundation - all rights reserved
+ * This code is licensed under the GPL 2.0 license, available at the root
+ * application directory.
+ */
 package org.geoserver.rest;
 
 import org.springframework.http.HttpStatus;
 
 /**
- * General purpose rest exceptions
+ * Rest Exception including {@link HttpStatus} code.
  */
 public class RestException extends RuntimeException {
+    /** serialVersionUID */
+    private static final long serialVersionUID = 5762645820684796082L;
+
     private final HttpStatus status;
 
     public RestException(String message, HttpStatus status) {
         super(message);
         this.status = status;
     }
 
-    public RestException(String s, HttpStatus status, Throwable t) {
-        super(s, t);
+    public RestException(String message, HttpStatus status, Throwable t) {
+        super(message, t);
         this.status = status;
     }
 
     public HttpStatus getStatus() {
         return status;
     }
+
+    @Override
+    public String toString() {
+        StringBuilder builder = new StringBuilder();
+        builder.append(getClass().getName());
+        if( status != null ){
+            builder.append(" ");
+            builder.append(status.value());
+            builder.append(" ");
+            builder.append(status.name());
+        }
+        String message = getLocalizedMessage();
+        if( message != null ){
+            builder.append(": ");
+            builder.append( message );
+        }
+        return builder.toString();
+    }
 }