Merge pull request #2017 from scireum/feature/SIRI-985-show-more-info…

…rmation-wrapped-exceptions

Shows more information for wrapped exceptions

src/main/java/sirius/biz/protocol/Protocols.java

@@ -156,7 +156,7 @@ private String buildErrorMessages(Throwable throwable) {
             // Therefore, the first element is skipped.
             Throwables.getCausalChain(throwable).stream().skip(1).forEach(cause -> {
                 stringBuilder.append("\n").append("Caused by: ").append(cause.getClass().getName()).append(":").append("\n");
-                stringBuilder.append(truncateErrorMessage(cause.getMessage(), numberOfCharactersPerMessage)).append("\n\n");
+                stringBuilder.append(truncateErrorMessage(determineErrorMessage(cause), numberOfCharactersPerMessage)).append("\n\n");
             });
         } catch (IllegalArgumentException exception) {
             // This happens if the causal chain has a circular reference.
@@ -167,6 +167,16 @@ private String buildErrorMessages(Throwable throwable) {
         return stringBuilder.toString();
     }
 
+    private String determineErrorMessage(Throwable throwable) {
+        if (Strings.isFilled(throwable.getMessage())) {
+            return throwable.getMessage();
+        }
+        if (Strings.areEqual(throwable.getClass().getName(), throwable.toString())) {
+            return "";
+        }
+        return throwable.toString();
+    }
+
     private String truncateErrorMessage(String errorMessage, int length) {
         int charsToPreserveFromStart = Math.max(0, length - NUMBER_OF_CHARS_TO_PRESERVE_AT_THE_END_OF_AN_ERROR_MESSAGE);
         return Strings.truncateMiddle(errorMessage, charsToPreserveFromStart, NUMBER_OF_CHARS_TO_PRESERVE_AT_THE_END_OF_AN_ERROR_MESSAGE);