diff --git a/restservice/src/main/java/com/plannaplan/security/cas/CasValidator.java b/restservice/src/main/java/com/plannaplan/security/cas/CasValidator.java
new file mode 100644
index 0000000..8cde61c
--- /dev/null
+++ b/restservice/src/main/java/com/plannaplan/security/cas/CasValidator.java
@@ -0,0 +1,7 @@
+package com.plannaplan.security.cas;
+
+public interface CasValidator {
+ 
+    String validate();
+    
+}
diff --git a/restservice/src/main/java/com/plannaplan/security/cas/DefaultUAMCasValidator.java b/restservice/src/main/java/com/plannaplan/security/cas/DefaultUAMCasValidator.java
index 6f69b3a..b5c2ad6 100755
--- a/restservice/src/main/java/com/plannaplan/security/cas/DefaultUAMCasValidator.java
+++ b/restservice/src/main/java/com/plannaplan/security/cas/DefaultUAMCasValidator.java
@@ -9,7 +9,7 @@ import org.apache.http.impl.client.CloseableHttpClient;
 import org.apache.http.impl.client.HttpClients;
 import org.apache.http.util.EntityUtils;
 
-public class DefaultUAMCasValidator {
+public class DefaultUAMCasValidator implements CasValidator {
     private static String CAS_URL = "https://cas.amu.edu.pl/cas";
     private final CloseableHttpClient httpClient = HttpClients.createDefault();
     private String service;
@@ -20,26 +20,32 @@ public class DefaultUAMCasValidator {
         this.ticket = ticket;
     }
 
-    public String validate() throws Exception, CasValidationExcepiton {
-        HttpGet request = new HttpGet(DefaultUAMCasValidator.CAS_URL + "/validate?service="
-                + URLEncoder.encode(this.service, "UTF-8") + "&ticket=" + URLEncoder.encode(this.ticket, "UTF-8"));
-        try (CloseableHttpResponse response = httpClient.execute(request)) {
+    @Override
+    public String validate() {
+        try {
+            HttpGet request = new HttpGet(DefaultUAMCasValidator.CAS_URL + "/validate?service="
+                    + URLEncoder.encode(this.service, "UTF-8") + "&ticket=" + URLEncoder.encode(this.ticket, "UTF-8"));
+            try (CloseableHttpResponse response = httpClient.execute(request)) {
 
-            HttpEntity entity = response.getEntity();
+                HttpEntity entity = response.getEntity();
 
-            String result = null;
-            if (entity != null) {
-                // return it as a String
-                result = EntityUtils.toString(entity);
-                if (result.replace("\n", "").trim().equals("no")) {
-                    throw new CasValidationExcepiton("Validation failed");
+                String result = null;
+                if (entity != null) {
+                    // return it as a String
+                    result = EntityUtils.toString(entity);
+                    if (result.replace("\n", "").trim().equals("no")) {
+                        throw new CasValidationExcepiton("Validation failed");
+                    }
                 }
+
+                String res = result.substring(result.indexOf('\n') + 1);
+                return res;
+
             }
-
-            String res = result.substring(result.indexOf('\n') + 1);
-            return res;
-
         }
 
+        catch (Exception e) {
+            throw new CasValidationExcepiton("Cas Validation has failed."); 
+        }
     }
 }