Fix: JAXB + Java >= 9 Class Loader Bug & Ensure Tomcat Deployment

- Problem: Jaxb + JAVA >= 9 Runtime + Tomcat = ClassNotFoundException:
  ContextFactory.

  Reason: Apparently, jaxb uses the "wrong" classloader (the system
  classloader via the thread classloader) and this classloader does
  not know about jaxb api's and implementations at runtime since
  oracle decided to move jaxb* out of JRE.

  Solution: create a new thread, override the thread's "thread"
  classloader with the "class" classloader and do all jaxb
  interactions in that thread. See:
  https://sjhannah.com/blog/2018/11/21/jaxb-hell-on-jdk-9/

- Move "run jaxb interactions in own thread with class class loader"
  code into own component (JaxbClassNotFoundFix,
  runInTheadWithClassClassLoader) and wrap ClientFactory and
  Marshaller code into the "runInTheadWithClassClassLoader".

- Ensure that app can be deployed in a Tomcat container (by following
  this guide: https://www.baeldung.com/spring-boot-war-tomcat-deploy)

1 files changed, 3 insertions, 2 deletions

diff --git a/src/main/java/at/gv/egiz/moazs/backend/DeliveryRequestBackend.java b/src/main/java/at/gv/egiz/moazs/backend/DeliveryRequestBackend.java
index 72f8ba0..46b0c2c 100644
--- a/src/main/java/at/gv/egiz/moazs/backend/DeliveryRequestBackend.java
+++ b/src/main/java/at/gv/egiz/moazs/backend/DeliveryRequestBackend.java
@@ -11,7 +11,8 @@ import at.gv.zustellung.app2mzs.xsd.DeliveryRequestType;
 import at.gv.zustellung.msg.xsd.App2ZusePort;
 import at.gv.zustellung.msg.xsd.DeliveryRequestStatusType;
 import at.gv.zustellung.tnvz.xsd.TNVZServicePort;
-import org.apache.log4j.Logger;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.annotation.Profile;
 import org.springframework.stereotype.Component;
@@ -28,7 +29,7 @@ import static java.lang.String.format;
 @Profile("!cluster")
 public class DeliveryRequestBackend implements Consumer<String> {
 
-    private static final Logger log = Logger.getLogger(DeliveryRequestBackend.class);
+    private static final Logger log = LoggerFactory.getLogger(DeliveryRequestBackend.class);
     private static final String MZS_PIPELINE_ERROR_MSG =
             "An error occured while processing the DeliveryRequest with AppDeliveryID=%s. ";
     private static final String DELIVERY_REQUEST_MISSING_ERROR_MSG =