troubleshooting ubuntus maven

README.md

@@ -21,3 +21,26 @@ Optionally, start the user interface by running:
 ```bash
 docker-compose up fda-ui
 ```
+
+### Troubleshooting
+
+Ubuntu 20.04 LTS
+
+Do not use maven provided my Ubuntu 20.4 LTS. It cannot handle those injections spring-boot wants it to do.
+
+It says: WARNING: An illegal reflective access operation has occurred
+WARNING: Illegal reflective access by com.google.inject.internal.cglib.core.$ReflectUtils$1 (file:/usr/share/maven/lib/guice.jar) to method java.lang.ClassLoader.defineClass(java.lang.String,byte[],int,int,java.security.ProtectionDomain)
+
+Install maven from Apache Org.:
+
+# Download maven e.g. 3.6.3
+wget https://www-us.apache.org/dist/maven/maven-3/3.6.3/binaries/apache-maven-3.6.3-bin.tar.gz -P /tmp
+
+# Untar downloaded file to /opt
+sudo tar xf /tmp/apache-maven-*.tar.gz -C /opt
+
+# Install the alternative version for the mvn in your system
+sudo update-alternatives --install /usr/bin/mvn mvn /opt/apache-maven-3.6.3/bin/mvn 363
+
+# Check if your configuration is ok. You may use your current or the 3.6.3 whenever you wish, running the command below.
+sudo update-alternatives --config mvn