From c76696c0e9025dd9e65af83b2a4d487343b6584b Mon Sep 17 00:00:00 2001
From: Matthias Ronge <matthias.ronge@zeutschel.de>
Date: Wed, 28 Oct 2020 15:36:16 +0100
Subject: [PATCH] Display root cause of error with its message

Fixes  #4073
---
 .../org/kitodo/production/helper/Helper.java  | 20 ++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/Kitodo/src/main/java/org/kitodo/production/helper/Helper.java b/Kitodo/src/main/java/org/kitodo/production/helper/Helper.java
index 0b197e2bec5..ff09debbfc6 100644
--- a/Kitodo/src/main/java/org/kitodo/production/helper/Helper.java
+++ b/Kitodo/src/main/java/org/kitodo/production/helper/Helper.java
@@ -33,6 +33,7 @@
 import javax.faces.application.FacesMessage;
 import javax.faces.context.FacesContext;
 
+import org.apache.commons.lang.StringUtils;
 import org.apache.logging.log4j.Level;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
@@ -161,12 +162,23 @@ public static void setErrorMessage(String title, final Object[] parameters) {
     public static void setErrorMessage(String title, Logger logger, Exception exception) {
         logger.error(title, exception);
         if (Objects.isNull(exception.getMessage()) || exception.getMessage().equals(title)) {
-            setErrorMessage(title);
+            setErrorMessage(getRootCause(exception));
         } else {
             setErrorMessage(title, exception.getMessage());
         }
     }
 
+    private static String getRootCause(Throwable problem) {
+        Throwable cause = problem.getCause();
+        String className = problem.getClass().getSimpleName();
+        if (Objects.nonNull(cause)) {
+            return className + " / " + getRootCause(cause);
+        } else {
+            String message = problem.getLocalizedMessage();
+            return StringUtils.isEmpty(message) ? className : className + ": " + message;
+        }
+    }
+
     /**
      * Set error message to message tag with given name 'title'. Substitute all
      * placeholders in message tag with elements of given array 'parameters'.
@@ -272,12 +284,6 @@ public static void setMessage(String control, String message, String description
      * übergeben.
      */
     private static void setMessage(String control, String message, String description, MessageLevel level) {
-        // Never forget: Strings are immutable
-        message = Objects.toString(message).replaceAll("<", "&lt;");
-        message = message.replaceAll(">", "&gt;");
-        description = Objects.toString(description).replaceAll("<", "&lt;");
-        description = description.replaceAll(">", "&gt;");
-
         String msg = getTranslation(message);
         String descript = getTranslation(description);