diff --git a/Backend/xslt-rest/src/main/java/com/r11/tools/xslt/SparkInitializer.java b/Backend/xslt-rest/src/main/java/com/r11/tools/xslt/SparkInitializer.java
index b52ac5e..0b412c9 100644
--- a/Backend/xslt-rest/src/main/java/com/r11/tools/xslt/SparkInitializer.java
+++ b/Backend/xslt-rest/src/main/java/com/r11/tools/xslt/SparkInitializer.java
@@ -49,6 +49,7 @@ public class SparkInitializer {
             resp.header("processor", "Saxon " + Saxon.getVersion() + " over s9api");
             return Saxon.getVersion();
         } catch (Exception ex) {
+            LOG.error("Error on retrieving engine version. " + ex);
             return ex.getMessage();
         }
     };
@@ -59,7 +60,6 @@ public class SparkInitializer {
      */
     private static Route xsdHandler = (Request req, Response resp) -> {
         String body = req.body();
-        LOG.info("Request: " + body);
         ObjectMapper mapper = new ObjectMapper();
         Map<String, String> requestMap = null;
         Map<String, String> responseMap = new HashMap<>();
@@ -82,7 +82,7 @@ public class SparkInitializer {
             responseMap.put("result", tmp);
             responseMap.put("status", "OK");
         } catch (Exception ex) {
-            LOG.error("Exception: "+ ex.getMessage());
+            LOG.error("Error on validation against XSD using Xalan. " + ex);
             responseMap.put("result", ex.getMessage());
             responseMap.put("status", "ERR");
             resp.status(400);
@@ -100,15 +100,13 @@ public class SparkInitializer {
      */
     private static Route xpathHandler = (Request req, Response resp) -> {
         String body = req.body();
-        LOG.info("Request: " + body);
         ObjectMapper mapper = new ObjectMapper();
         Map<String, String> requestMap = null;
         Map<String, String> responseMap = new HashMap<>();
         try {
             requestMap = mapper.readValue(body, Map.class);
         } catch (JsonMappingException ex) {
-            LOG.error("Exception: "+ ex.getMessage());
-            //ex.printStackTrace();
+            LOG.error("JSON mapping error. " + ex);
         }
 
         String data = requestMap.get("data");
@@ -124,57 +122,51 @@ public class SparkInitializer {
         if (processor == null) {
             return "saxon, xalan";
         }
-        try {
-            switch (processor) {
-                case "saxon":
-                    resp.header("processor", "Saxon " + Saxon.getVersion() + " " + version + " over s9api");
-                    //LOG.info("Processing start...");
-                    timeStart = System.currentTimeMillis();
-                    try {
-                        tmp = Saxon.processXPath(data, query, version).trim();
-                        responseMap.put("result", tmp);
-                        responseMap.put("status", "OK");
-                    } catch (Exception ex) {
-                        LOG.error("Exception: "+ ex.getMessage());
-                        responseMap.put("result", ex.getMessage());
-                        responseMap.put("status", "ERR");
-                        resp.status(400);
-                    }
-                    duration = System.currentTimeMillis() - timeStart;
-                    //System.out.println("end(" + duration + ")");
-                    LOG.info("Request" + body + " processed in " + duration + " ms.");
-                    responseMap.put("processor", "Saxon " + Saxon.getVersion() + " " + version + " over s9api");
-                    responseMap.put("time", "" + duration);
-                    resp.body(mapper.writeValueAsString(responseMap));
-                    return resp;
 
-                case "xalan":
-                    resp.header("processor", Xalan.getVersion());
-                    timeStart = System.currentTimeMillis();
-                    try {
-                        tmp = Xalan.processXPath(data, query).trim();
-                        responseMap.put("result", tmp);
-                        responseMap.put("status", "OK");
-                    } catch (Exception ex) {
-                        LOG.error("Exception: "+ ex.getMessage());
-                        responseMap.put("result", ex.getMessage());
-                        responseMap.put("status", "ERR");
-                        resp.status(400);
-                    }
-                    duration = System.currentTimeMillis() - timeStart;
-                    responseMap.put("processor", Xalan.getVersion());
+        switch (processor) {
+            case "saxon":
+                resp.header("processor", "Saxon " + Saxon.getVersion() + " " + version + " over s9api");
+                timeStart = System.currentTimeMillis();
+                try {
+                    tmp = Saxon.processXPath(data, query, version).trim();
                     responseMap.put("result", tmp);
-                    responseMap.put("time", Long.toString(duration));
-                    resp.body(mapper.writeValueAsString(responseMap));
-                    return resp;
+                    responseMap.put("status", "OK");
+                } catch (Exception ex) {
+                    LOG.error("Error on processing XPath using Saxon. " + ex);
+                    responseMap.put("result", ex.getMessage());
+                    responseMap.put("status", "ERR");
+                    resp.status(400);
+                }
+                duration = System.currentTimeMillis() - timeStart;
+                LOG.info("Request" + body + " processed in " + duration + " ms.");
+                responseMap.put("processor", "Saxon " + Saxon.getVersion() + " " + version + " over s9api");
+                responseMap.put("time", "" + duration);
+                resp.body(mapper.writeValueAsString(responseMap));
+                return resp;
 
-                default:
-                    return "saxon, xalan";
-            }
+            case "xalan":
+                resp.header("processor", Xalan.getVersion());
+                timeStart = System.currentTimeMillis();
+                try {
+                    tmp = Xalan.processXPath(data, query).trim();
+                    responseMap.put("result", tmp);
+                    responseMap.put("status", "OK");
+                } catch (Exception ex) {
+                    LOG.error("Error on processing XPath using Xalan. " + ex);
+                    responseMap.put("result", ex.getMessage());
+                    responseMap.put("status", "ERR");
+                    resp.status(400);
+                }
+                duration = System.currentTimeMillis() - timeStart;
+                LOG.info("Request: " + body + " processed in " + duration + " ms.");
+                responseMap.put("processor", Xalan.getVersion());
+                responseMap.put("result", tmp);
+                responseMap.put("time", Long.toString(duration));
+                resp.body(mapper.writeValueAsString(responseMap));
+                return resp;
 
-        } catch (Exception ex) {
-            ex.printStackTrace();
-            return ex.getMessage();
+            default:
+                return "saxon, xalan";
         }
     };
 
@@ -188,11 +180,8 @@ public class SparkInitializer {
         Map<String, String> responseMap = new HashMap<>();
         try {
             jsonMap = mapper.readValue(body, Map.class);
-            LOG.info(jsonMap);
-            //System.out.println(jsonMap);
         } catch (JsonMappingException ex) {
-            LOG.error("Exception: "+ ex.getMessage());
-            //ex.printStackTrace();
+            LOG.error("JSON mapping error. " + ex);
         }
         String data = jsonMap.get("data");
         String query = jsonMap.get("process");
@@ -202,54 +191,51 @@ public class SparkInitializer {
         if (processor == null) {
             return "saxon, xalan";
         }
-        try {
-            String tmp;
-            long timeStart;
-            long duration;
-            switch (processor) {
-                case "saxon":
-                    timeStart = System.currentTimeMillis();
-                    try {
-                        tmp = Saxon.processXSLT(data, query);
-                        responseMap.put("result", tmp);
-                        responseMap.put("status", "OK");
-                    } catch (Exception ex) {
-                        LOG.error("Exception: "+ ex.getMessage());
-                        responseMap.put("result", ex.getMessage());
-                        responseMap.put("status", "ERR");
-                        resp.status(400);
-                    }
 
+        String tmp;
+        long timeStart;
+        long duration;
+        switch (processor) {
+            case "saxon":
+                timeStart = System.currentTimeMillis();
+                try {
+                    tmp = Saxon.processXSLT(data, query);
+                    responseMap.put("result", tmp);
+                    responseMap.put("status", "OK");
+                } catch (Exception ex) {
+                    LOG.error("Error on processing XSLT using Saxon. " + ex);
+                    responseMap.put("result", ex.getMessage());
+                    responseMap.put("status", "ERR");
+                    resp.status(400);
+                }
+                duration = System.currentTimeMillis() - timeStart;
+                LOG.info("Request: " + body + " processed in " + duration + " ms.");
+                responseMap.put("processor", "Saxon " + Saxon.getVersion() + " " + version);
+                responseMap.put("time", Long.toString(duration));
+                resp.body(mapper.writeValueAsString(responseMap));
+                return resp;
 
-                    duration = System.currentTimeMillis() - timeStart;
-                    responseMap.put("processor", "Saxon " + Saxon.getVersion() + " " + version);
-                    responseMap.put("time", Long.toString(duration));
-                    resp.body(mapper.writeValueAsString(responseMap));
-                    return resp;
+            case "xalan":
+                timeStart = System.currentTimeMillis();
+                try {
+                    tmp = Xalan.processXSLT(data, query);
+                    responseMap.put("result", tmp);
+                    responseMap.put("status", "OK");
+                } catch (Exception ex) {
+                    LOG.error("Error on processing XSLT using Xalan. " + ex);
+                    responseMap.put("result", ex.getMessage());
+                    responseMap.put("status", "ERR");
+                    resp.status(400);
+                }
+                duration = System.currentTimeMillis() - timeStart;
+                LOG.info("Request: " + body + " processed in " + duration + " ms.");
+                responseMap.put("processor", Xalan.getVersion());
+                responseMap.put("time", Long.toString(duration));
+                resp.body(mapper.writeValueAsString(responseMap));
+                return resp;
 
-                case "xalan":
-                    timeStart = System.currentTimeMillis();
-                    try {
-                        tmp = Xalan.processXSLT(data, query);
-                        responseMap.put("result", tmp);
-                        responseMap.put("status", "OK");
-                    } catch (Exception ex) {
-                        LOG.error("Exception: "+ ex.getMessage());
-                        responseMap.put("result", ex.getMessage());
-                        responseMap.put("status", "ERR");
-                        resp.status(400);
-                    }
-                    duration = System.currentTimeMillis() - timeStart;
-                    responseMap.put("processor", Xalan.getVersion());
-                    responseMap.put("time", Long.toString(duration));
-                    resp.body(mapper.writeValueAsString(responseMap));
-                    return resp;
-
-                default:
-                    return "saxon, xalan";
-            }
-        } catch (Exception ex) {
-            return ex.getMessage();
+            default:
+                return "saxon, xalan";
         }
     };
 }