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, 11 insertions, 1 deletions

diff --git a/src/main/java/at/gv/egiz/moazs/MoaZS.java b/src/main/java/at/gv/egiz/moazs/MoaZS.java
index 3009745..e4e4acc 100644
--- a/src/main/java/at/gv/egiz/moazs/MoaZS.java
+++ b/src/main/java/at/gv/egiz/moazs/MoaZS.java
@@ -3,9 +3,19 @@ package at.gv.egiz.moazs;
 
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.builder.SpringApplicationBuilder;
+import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;
+
+import java.net.URL;
+import java.net.URLClassLoader;
 
 @SpringBootApplication
-public class MoaZS {
+public class MoaZS extends SpringBootServletInitializer {
+
+    @Override
+    protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {
+        return builder.sources(MoaZS.class);
+    }
 
     public static void main(String[] args) {
         SpringApplication.run(MoaZS.class, args);