[JAVA][BUG] Do not use valueOf for numeric types for generating inner enums

[timon-sbr]

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Technical Comittee

@bbdouglas (2017/07) @sreeshas (2017/08) @jfiala (2017/08) @lukoyanov (2017/09) @cbornet (2017/09) @jeff9finger (2018/01) @karismann (2019/03) @Zomzog (2019/04) @lwlee2608 (2019/10) @martin-mfg (2023/08)

Description

The template file src/main/resources/Java/modelInnerEnum.mustache was using the valueOf() method to create instances for enum fields. This does not work for every Object, because valueOf() is not implemented in every possible Object. BigDecimal for example does not provide the valueOf(BigDecimal) method. This behaviour results in invalid code through generation.
To fix this, I decided to only use the valueOf method, for non numeric types. It seems the decision to use the valueOf method was, to fix a bug for Boolean values (see: PR-19815 ). So this fix should be non breaking.

This PR closes #20188

[wing328]

@timon-sbr thanks for the PR.

Can you please add a test case or 2 in modules/openapi-generator/src/test/resources/3_0/java/petstore-with-fake-endpoints-models-for-testing-okhttp-gson.yaml and then regenerate the samples?

[timon-sbr]

@wing328 thanks for the review. I've added some test data to modules/openapi-generator/src/test/resources/3_0/java/petstore-with-fake-endpoints-models-for-testing-okhttp-gson.yaml and regenerated the samples. Can you please check, if this is enough? I'm not sure, if I've also have to add java code to test the behaviour.

[wing328]

i did a test with https://raw.githubusercontent.com/OpenAPITools/openapi-generator/a8d3e7da44e268d32818e6d02d0a111d58f7bbea/modules/openapi-generator/src/test/resources/3_0/java/petstore-with-fake-endpoints-models-for-testing-okhttp-gson.yaml using the latest master CLI JAR but the output compiles without issue

is my understanding correct that the test spec (with the newly added test cases you just added) should generate output with compilation errors as described in the issue?

[timon-sbr]

Hi @wing328 the Test Spec I've added tests the bugfix, so the output should generate a valid result, which is the fix of the issue.

[wing328]

In the issue, you mentioned

The generated Code produces compiler errors, because it tries to create instances of BigDecimal with

but I couldn't repeat the compilation errors using the test spec you updated in this PR: https://raw.githubusercontent.com/OpenAPITools/openapi-generator/a8d3e7da44e268d32818e6d02d0a111d58f7bbea/modules/openapi-generator/src/test/resources/3_0/java/petstore-with-fake-endpoints-models-for-testing-okhttp-gson.yaml

in other words, how did you produce the compilation errors?