[Java][WebClient] Missing Spring dependency in build.gradle

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• What's the version of OpenAPI Generator used?
• Have you search for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Bounty to sponsor the fix (example)

[Java][WebClient]
Bug

Description

Missing dependency org.springframework in build.gradle using Java with library webclient

Swagger-codegen version

Master (5.0.0)

Swagger declaration file content or url

After generating code with java and library webclient. gradle.build file is missing a dependency (org.springframework) which makes building the project with gradle not possible. Note that building it with Maven works fine

Command line used for generation

I am using the following command

java -jar modules/openapi-generator-cli/target/openapi-generator-cli.jar generate -i https://raw.githubusercontent.com/openapitools/openapi-generator/master/modules/openapi-generator/src/test/resources/2_0/petstore.yaml -g java --library webclient -o /tmp/javaWebclient

Steps to reproduce

Using the command above and building project with gradle leads to import errors e.g.
error: package org.springframework.core does not exist import org.springframework.core.ParameterizedTypeReference;

Related issues/PRs

Suggest a fix/enhancement

Adding the following dependency to build.gradle.mustache (in dependencies java webclient)

compile "org.springframework:spring-webflux:$spring_web_version"

Start by running the provided OpenAPI Generator command with the Java WebClient library, then build the generated project with Gradle to reproduce the missing import errors. Inspect build.gradle.mustache and compare its WebClient dependencies with the Maven output; done means the generated Gradle project builds with the required Spring dependency.