- Add README.md

- Avoid sending a null-Error-object, which increases the complexity on the controller's side. Instead, send an Error object with "null" members.

README.md

@@ -0,0 +1,9 @@
+# Urls_Worker
+
+This is the Worker's Application.<br>
+It requests assignments from the [controller](https://code-repo.d4science.org/lsmyrnaios/UrlsController) and processes them.<br>
+[...] <br>
+
+To install and run the application, run ```git clone``` and then execute the ```installAndRun.sh``` script.<br>
+That script, installs the [PublicationsRetriever](https://github.com/LSmyrnaios/PublicationsRetriever), as a library and then compiles and runs the whole Application.<br>
+<br>

src/main/java/eu/openaire/urls_worker/plugins/PublicationsRetrieverPlugin.java

@@ -191,7 +191,10 @@ public class PublicationsRetrieverPlugin {
                         e.printStackTrace();
                     }
                 }
-            } else {
+
+                error = new Error(null, null);  // We do not want to send a "null" object, since it just adds more complicated handling in the controller..
+            }
+            else {
                 status = "non-accessible";
                 if ( data.getCouldRetry().equals("true") )
                     error = new Error(Error.ErrorType.couldRetry, comment);