Kotlin enums are always marked as required if used in Java controllers.

Fixes #2622

springdoc-openapi-tests/springdoc-openapi-kotlin-webmvc-tests/pom.xml

@@ -78,6 +78,36 @@
 					</dependency>
 				</dependencies>
 			</plugin>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-compiler-plugin</artifactId>
+				<executions>
+					<!-- Replacing default-compile as it is treated specially by Maven -->
+					<execution>
+						<id>default-compile</id>
+						<phase>none</phase>
+					</execution>
+					<!-- Replacing default-testCompile as it is treated specially by Maven -->
+					<execution>
+						<id>default-testCompile</id>
+						<phase>none</phase>
+					</execution>
+					<execution>
+						<id>java-compile</id>
+						<phase>compile</phase>
+						<goals>
+							<goal>compile</goal>
+						</goals>
+					</execution>
+					<execution>
+						<id>java-test-compile</id>
+						<phase>test-compile</phase>
+						<goals>
+							<goal>testCompile</goal>
+						</goals>
+					</execution>
+				</executions>
+			</plugin>
 		</plugins>
 	</build>
 </project>