TENTACLES-3: Provde help text in case number of arguments is to low

-To prevent NPEs the number of parameters is checked. Output is printed via logger to comply with the current Tentacles architecture.



git-svn-id: https://svn.apache.org/repos/asf/creadur/tentacles/trunk@1617605 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/src/main/java/org/apache/creadur/tentacles/Main.java b/src/main/java/org/apache/creadur/tentacles/Main.java
index 9dc5b69..42809c2 100644
--- a/src/main/java/org/apache/creadur/tentacles/Main.java
+++ b/src/main/java/org/apache/creadur/tentacles/Main.java
@@ -99,7 +99,16 @@
     }
 
     public static void main(final String[] args) throws Exception {
-        new Main(args).main();
+    	
+    	log.info("Launching Apache Tentacles ...");
+    	
+    	if(args == null || args.length < 1) {
+    		log.error("Error: Input parameter missing - you did not specify any component to run Apache Tentacles on.");
+    		log.error("Please launch Apache Tentacles with an URI to work on such as 'https://repository.apache.org/content/repositories/orgapachecreadur-1000/'.");
+    	} else {
+    		new Main(args).main();
+    	}
+    	
     }
 
     private void main() throws Exception {