java-vertx generated code fails to run with nullpointerexception @ SwaggerRouter.getBasePath(SwaggerRouter.java:129)

[shades198]

Platform config:
OS: RHEL 7.8
Java: 11
openapi-generator-cli version: 4.1.2

I tried generating java-vertx code for a swagger-2 spec file and an openapi v3 spec file. Using below command
java -jar openapi-generator-cli.jar generate -g java-vertx -i ~/Documents/Work/swaggers\ for\ testing/Cards.yaml -o ~/GeneratedCode/openapi-java-vertx

Given swagger is correct without any issues. It opens jst fine on editor.swagger.io

Code was successfully generated. But had two issues

1. In pom.xml vertx-swagger-router.version was empty, no provided
2. After fixing above version, code failed to start with a nullpointerexception.

Stacktrace for pt.2

java.lang.NullPointerException
	at com.github.phiz71.vertx.swagger.router.SwaggerRouter.getBasePath(SwaggerRouter.java:129)
	at com.github.phiz71.vertx.swagger.router.SwaggerRouter.swaggerRouter(SwaggerRouter.java:75)
	at com.github.phiz71.vertx.swagger.router.SwaggerRouter.swaggerRouter(SwaggerRouter.java:70)
	at org.openapitools.server.api.MainApiVerticle.lambda$start$1(MainApiVerticle.java:50)
	at io.vertx.core.impl.FutureImpl.checkCallHandler(FutureImpl.java:188)
	at io.vertx.core.impl.FutureImpl.setHandler(FutureImpl.java:100)
	at io.vertx.core.impl.ContextImpl.lambda$null$0(ContextImpl.java:287)
	at io.vertx.core.impl.ContextImpl.lambda$wrapTask$2(ContextImpl.java:337)
	at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:163)
	at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:403)
	at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:445)
	at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858)
	at java.base/java.lang.Thread.run(Thread.java:834)

Inside MainApiVerticle.java are below line

FileSystem vertxFileSystem = vertx.fileSystem();
        vertxFileSystem.readFile("openapi.json", readFile -> {
            if (readFile.succeeded()) {
                Swagger swagger = new SwaggerParser().parse(readFile.result().toString(Charset.forName("utf-8")));
                Router swaggerRouter = SwaggerRouter.swaggerRouter(router, swagger, vertx.eventBus(), new OperationIdServiceIdResolver());

readFile() operation succeeds, however in next line value of swagger comes out as null. openapi.json was indeed present inside src/main/resources.
Please help.

[kay-schecker]

Please see #31