[BUG] Java generators add underscore to enums

[joystuffs]

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?
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Description

after updating to version 7.12.0 the current configuration produces enums with unexpected 'underscore'

 <configuration>
                            <inputSpec>${project.basedir}/src/main/resources/api.yaml</inputSpec>
                            <generatorName>java</generatorName>
                            <skipValidateSpec>true</skipValidateSpec>
                            <strictSpec>true</strictSpec>
                            <generateApis>false</generateApis>
                            <generateSupportingFiles>false</generateSupportingFiles>
                            <generateModelTests>false</generateModelTests>
                            <apiPackage>com.api</apiPackage>
                            <modelPackage>com.api</modelPackage>
                            <typeMappings>
                                <typeMapping>Double=java.math.BigDecimal</typeMapping>
                                <typeMapping>Boolean=boolean</typeMapping>
                                <typeMapping>Date=String</typeMapping>
                                <typeMapping>UUID=String</typeMapping>
                            </typeMappings>
                            <importMappings>
                                <importMapping>Double=java.math.BigDecimal</importMapping>
                                <importMapping>Boolean=boolean</importMapping>
                                <importMapping>Date=String</importMapping>
                                <importMapping>UUID=String</importMapping>
                            </importMappings>
                            <configOptions>
                                <useJakartaEe>true</useJakartaEe>
                                <dateLibrary>custom</dateLibrary>
                                <library>resteasy</library>
                                <sourceFolder>src/gen/java/main</sourceFolder>
                                <openApiNullable>false</openApiNullable>
                                <additionalModelTypeAnnotations>@lombok.Builder @lombok.AllArgsConstructor</additionalModelTypeAnnotations>
                                <performBeanValidation>true</performBeanValidation>
                                <useBeanValidation>true</useBeanValidation>
                                <serializationLibrary>jackson</serializationLibrary>
                            </configOptions>
                        </configuration>

I tried to play around adding :

<enumPropertyNaming>original</enumPropertyNaming>

but the generator throws exception as the only types allowed are MACRO_CASE and legacy

even when I try to add :

removeEnumValuePrefix=true

or any similar/related enum config, nothing happens.

I looked into the source code but I couldn't fine a way to over come this problem and keep the previous behaviour.

probably there is something I miss with the configuration and that leads to this enum generation issue.

below the generated enum after the update

C2_C("C2C"),
 
 CORE("CORE");

before the update with version 7.5.0

B2B("C2C"),
 
 CORE("CORE");

openapi-generator version

7.12.0

OpenAPI declaration file content or url

below the example of the openapi definition

"Type": {
        "type": "string",
        "description": "Type [C2C, CORE]",
        "enum": [
          "C2C",
          "CORE"
        ]
      }

Generation Details

we use the openapi-generator-maven-plugin

version : 7.12.0

Steps to reproduce

just run the maven command with the two versions and you will be able to replicate the issue

Related issues/PRs

Suggest a fix

[wing328]

did you try setting the option enumPropertyNaming to legacy?

ref: https://openapi-generator.tech/docs/generators/java/

[joystuffs]

thank you for the reference. that solved the issue.