error handling, excel, bug fixes, name fixes (#57)

src/main/java/stirling/software/SPDF/utils/ErrorUtils.java

@@ -0,0 +1,32 @@
+package stirling.software.SPDF.utils;
+
+import java.io.PrintWriter;
+import java.io.StringWriter;
+
+import org.springframework.ui.Model;
+import org.springframework.web.servlet.ModelAndView;
+
+public class ErrorUtils {
+
+    public static Model exceptionToModel(Model model, Exception ex) {
+        StringWriter sw = new StringWriter();
+        ex.printStackTrace(new PrintWriter(sw));
+        String stackTrace = sw.toString();
+
+        model.addAttribute("errorMessage", ex.getMessage());
+        model.addAttribute("stackTrace", stackTrace);
+        return model;
+    }
+
+    public static ModelAndView exceptionToModelView(Model model, Exception ex) {
+        StringWriter sw = new StringWriter();
+        ex.printStackTrace(new PrintWriter(sw));
+        String stackTrace = sw.toString();
+
+        ModelAndView modelAndView = new ModelAndView();
+        modelAndView.addObject("errorMessage", ex.getMessage());
+        modelAndView.addObject("stackTrace", stackTrace);
+        return modelAndView;
+    }
+    
+}