Also ship the API in the old javax namespace to aid transition

jakarta-servlet.spec

@@ -2,7 +2,7 @@
 
 Name:           jakarta-servlet
 Version:        5.0.0
-Release:        1%{?dist}
+Release:        2%{?dist}
 Summary:        Server-side API for handling HTTP requests and responses
 # most of the project is EPL-2.0 or GPLv2 w/exceptions,
 # but some files still have Apache-2.0 license headers:
@@ -47,6 +47,13 @@ This package contains the API documentation for %{name}.
 # do not build specification documentation
 %pom_disable_module spec
 
+# Copy to old package name
+# TODO: Remove when all dependencies are migrated from javax.servlet to jakarta.servlet
+cp -pr api/src/main/java/jakarta api/src/main/java/javax
+sed -i -e 's/jakarta\./javax./g' $(find api/src/main/java/javax -name *.java)
+%pom_xpath_replace pom:instructions/pom:Export-Package \
+  '<Export-Package>jakarta.servlet.*,javax.servlet.*;version="4.0.0"</Export-Package>' api
+
 # do not install useless parent POM
 %mvn_package jakarta.servlet:servlet-parent __noinstall
 
@@ -80,6 +87,9 @@ This package contains the API documentation for %{name}.
 
 
 %changelog
+* Wed Aug 19 2020 Mat Booth <mat.booth@redhat.com> - 5.0.0-2
+- Also ship the API in the old javax namespace to aid transition
+
 * Thu Aug 13 2020 Fabio Valentini <decathorpe@gmail.com> - 5.0.0-1
 - Initial package renamed from glassfish-servlet-api.